#2610 Add support for conditions on source parameters + fix incorrect use of source parameter in presence check method (#3543)

The new `@SourceParameterCondition` is also going to cover the problems in #3270 and #3459.
The changes in the `MethodFamilySelector` are also fixing #3561

core/src/main/java/org/mapstruct/Condition.java

@@ -11,26 +11,35 @@ import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
 /**
- * This annotation marks a method as a <em>presence check method</em> to check check for presence in beans.
+ * This annotation marks a method as a <em>presence check method</em> to check for presence in beans
+ * or it can be used to define additional check methods for something like source parameters.
  * <p>
- * By default bean properties are checked against {@code null} or using a presence check method in the source bean.
+ * By default, bean properties are checked against {@code null} or using a presence check method in the source bean.
  * If a presence check method is available then it will be used instead.
  * <p>
  * Presence check methods have to return {@code boolean}.
  * The following parameters are accepted for the presence check methods:
  *     <ul>
  *         <li>The parameter with the value of the source property.
- *         e.g. the value given by calling {@code getName()} for the name property of the source bean</li>
+ *         e.g. the value given by calling {@code getName()} for the name property of the source bean
+ *         - only possible when using the {@link ConditionStrategy#PROPERTIES}
+ *         </li>
  *         <li>The mapping source parameter</li>
  *         <li>{@code @}{@link Context} parameter</li>
- *         <li>{@code @}{@link TargetPropertyName} parameter</li>
+ *         <li>
- *         <li>{@code @}{@link SourcePropertyName} parameter</li>
+ *             {@code @}{@link TargetPropertyName} parameter -
+ *             only possible when using the {@link ConditionStrategy#PROPERTIES}
+ *         </li>
+ *         <li>
+ *             {@code @}{@link SourcePropertyName} parameter -
+ *             only possible when using the {@link ConditionStrategy#PROPERTIES}
+ *         </li>
  *     </ul>
  *
  * <strong>Note:</strong> The usage of this annotation is <em>mandatory</em>
  * for a method to be considered as a presence check method.
  *
- * <pre><code>
+ * <pre><code class='java'>
  * public class PresenceCheckUtils {
  *
  *   &#64;Condition
@@ -45,11 +54,10 @@ import java.lang.annotation.Target;
  *     MovieDto map(Movie movie);
  * }
  * </code></pre>
- *
+ * <p>
  * The following implementation of {@code MovieMapper} will be generated:
  *
- * <pre>
+ * <pre><code class='java'>
- * <code>
  * public class MovieMapperImpl implements MovieMapper {
  *
  *     &#64;Override
@@ -67,14 +75,22 @@ import java.lang.annotation.Target;
  *         return movieDto;
  *     }
  * }
- * </code>
+ * </code></pre>
- * </pre>
+ * <p>
+ * This annotation can also be used as a meta-annotation to define the condition strategy.
  *
  * @author Filip Hrisafov
+ * @see SourceParameterCondition
  * @since 1.5
  */
-@Target({ ElementType.METHOD })
+@Target({ ElementType.METHOD, ElementType.ANNOTATION_TYPE })
 @Retention(RetentionPolicy.CLASS)
 public @interface Condition {
 
+    /**
+     * @return the places where the condition should apply to
+     * @since 1.6
+     */
+    ConditionStrategy[] appliesTo() default ConditionStrategy.PROPERTIES;
+
 }

core/src/main/java/org/mapstruct/ConditionStrategy.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct;
+
+/**
+ * Strategy for defining what to what a condition (check) method is applied to
+ *
+ * @author Filip Hrisafov
+ * @since 1.6
+ */
+public enum ConditionStrategy {
+    /**
+     * The condition method should be applied whether a property should be mapped.
+     */
+    PROPERTIES,
+    /**
+     * The condition method should be applied to check if a source parameters should be mapped.
+     */
+    SOURCE_PARAMETERS,
+}

core/src/main/java/org/mapstruct/SourceParameterCondition.java

@@ -0,0 +1,74 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * This annotation marks a method as a <em>check method</em> to check if a source parameter needs to be mapped.
+ * <p>
+ * By default, source parameters are checked against {@code null}, unless they are primitives.
+ * <p>
+ * Check methods have to return {@code boolean}.
+ * The following parameters are accepted for the presence check methods:
+ *     <ul>
+ *         <li>The mapping source parameter</li>
+ *         <li>{@code @}{@link Context} parameter</li>
+ *     </ul>
+ *
+ * <strong>Note:</strong> The usage of this annotation is <em>mandatory</em>
+ * for a method to be considered as a source check method.
+ *
+ * <pre><code class='java'>
+ * public class PresenceCheckUtils {
+ *
+ *   &#64;SourceParameterCondition
+ *   public static boolean isDefined(Car car) {
+ *      return car != null &#38;&#38; car.getId() != null;
+ *   }
+ * }
+ *
+ * &#64;Mapper(uses = PresenceCheckUtils.class)
+ * public interface CarMapper {
+ *
+ *     CarDto map(Car car);
+ * }
+ * </code></pre>
+ *
+ * The following implementation of {@code CarMapper} will be generated:
+ *
+ * <pre><code class='java'>
+ * public class CarMapperImpl implements CarMapper {
+ *
+ *     &#64;Override
+ *     public CarDto map(Car car) {
+ *         if ( !PresenceCheckUtils.isDefined( car ) ) {
+ *             return null;
+ *         }
+ *
+ *         CarDto carDto = new CarDto();
+ *
+ *         carDto.setId( car.getId() );
+ *         // ...
+ *
+ *         return carDto;
+ *     }
+ * }
+ * </code></pre>
+ *
+ * @author Filip Hrisafov
+ * @since 1.6
+ * @see Condition @Condition
+ */
+@Target({ ElementType.METHOD })
+@Retention(RetentionPolicy.CLASS)
+@Condition(appliesTo = ConditionStrategy.SOURCE_PARAMETERS)
+public @interface SourceParameterCondition {
+
+}

documentation/src/main/asciidoc/chapter-10-advanced-mapping-options.asciidoc

@@ -303,8 +303,10 @@ null check, regardless the value of the `NullValueCheckStrategy` to avoid additi
 
 Conditional Mapping is a type of <<source-presence-check>>.
 The difference is that it allows users to write custom condition methods that will be invoked to check if a property needs to be mapped or not.
+Conditional mapping can also be used to check if a source parameter should be mapped or not.
 
-A custom condition method is a method that is annotated with `org.mapstruct.Condition` and returns `boolean`.
+A custom condition method for properties is a method that is annotated with `org.mapstruct.Condition` and returns `boolean`.
+A custom condition method for source parameters is annotated with `org.mapstruct.SourceParameterCondition`, `org.mapstruct.Condition(appliesTo = org.mapstruct.ConditionStrategy#SOURCE_PARAMETERS)` or meta-annotated with `Condition(appliesTo = ConditionStrategy#SOURCE_PARAMETERS)`
 
 e.g. if you only want to map a String property when it is not `null`, and it is not empty then you can do something like:
 
@@ -484,6 +486,55 @@ Methods annotated with `@Condition` in addition to the value of the source prope
 <<selection-based-on-qualifiers>> is also valid for `@Condition` methods.
 In order to use a more specific condition method you will need to use one of `Mapping#conditionQualifiedByName` or `Mapping#conditionQualifiedBy`.
 
+If we want to only map cars that have an id provided then we can do something like:
+
+
+.Mapper using custom condition source parameter check method
+====
+[source, java, linenums]
+[subs="verbatim,attributes"]
+----
+@Mapper
+public interface CarMapper {
+
+    CarDto carToCarDto(Car car);
+
+    @SourceParameterCondition
+    default boolean hasCar(Car car) {
+        return car != null && car.getId() != null;
+    }
+}
+----
+====
+
+The generated mapper will look like:
+
+.Custom condition source parameter check generated implementation
+====
+[source, java, linenums]
+[subs="verbatim,attributes"]
+----
+// GENERATED CODE
+public class CarMapperImpl implements CarMapper {
+
+    @Override
+    public CarDto carToCarDto(Car car) {
+        if ( !hasCar( car ) ) {
+            return null;
+        }
+
+        CarDto carDto = new CarDto();
+
+        carDto.setOwner( car.getOwner() );
+
+        // Mapping of other properties
+
+        return carDto;
+    }
+}
+----
+====
+
 [[exceptions]]
 === Exceptions
 

processor/src/main/java/org/mapstruct/ap/internal/gem/ConditionStrategyGem.java

@@ -0,0 +1,15 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.internal.gem;
+
+/**
+ * @author Filip Hrisafov
+ */
+public enum ConditionStrategyGem {
+
+    PROPERTIES,
+    SOURCE_PARAMETERS
+}

processor/src/main/java/org/mapstruct/ap/internal/model/BeanMappingMethod.java

@@ -411,6 +411,26 @@ public class BeanMappingMethod extends NormalTypeMappingMethod {
                 removeMappingReferencesWithoutSourceParameters( afterMappingReferencesWithFinalizedReturnType );
             }
 
+            Map<String, PresenceCheck> presenceChecksByParameter = new LinkedHashMap<>();
+            for ( Parameter sourceParameter : method.getSourceParameters() ) {
+                PresenceCheck parameterPresenceCheck = PresenceCheckMethodResolver.getPresenceCheckForSourceParameter(
+                    method,
+                    selectionParameters,
+                    sourceParameter,
+                    ctx
+                );
+                if ( parameterPresenceCheck != null ) {
+                    presenceChecksByParameter.put( sourceParameter.getName(), parameterPresenceCheck );
+                }
+                else if ( !sourceParameter.getType().isPrimitive() ) {
+                    presenceChecksByParameter.put(
+                        sourceParameter.getName(),
+                        new NullPresenceCheck( sourceParameter.getName() )
+                    );
+                }
+            }
+
+
             return new BeanMappingMethod(
                 method,
                 getMethodAnnotations(),
@@ -426,7 +446,8 @@ public class BeanMappingMethod extends NormalTypeMappingMethod {
                 afterMappingReferencesWithFinalizedReturnType,
                 finalizeMethod,
                 mappingReferences,
-                subclasses
+                subclasses,
+                presenceChecksByParameter
             );
         }
 
@@ -1891,7 +1912,8 @@ public class BeanMappingMethod extends NormalTypeMappingMethod {
                               List<LifecycleCallbackMethodReference> afterMappingReferencesWithFinalizedReturnType,
                               MethodReference finalizerMethod,
                               MappingReferences mappingReferences,
-                              List<SubclassMapping> subclassMappings) {
+                              List<SubclassMapping> subclassMappings,
+                              Map<String, PresenceCheck> presenceChecksByParameter) {
         super(
             method,
             annotations,
@@ -1923,18 +1945,12 @@ public class BeanMappingMethod extends NormalTypeMappingMethod {
         // parameter mapping.
         this.mappingsByParameter = new HashMap<>();
         this.constantMappings = new ArrayList<>( propertyMappings.size() );
-        this.presenceChecksByParameter = new LinkedHashMap<>();
+        this.presenceChecksByParameter = presenceChecksByParameter;
         this.constructorMappingsByParameter = new LinkedHashMap<>();
         this.constructorConstantMappings = new ArrayList<>();
         Set<String> sourceParameterNames = new HashSet<>();
         for ( Parameter sourceParameter : getSourceParameters() ) {
             sourceParameterNames.add( sourceParameter.getName() );
-            if ( !sourceParameter.getType().isPrimitive() ) {
-                presenceChecksByParameter.put(
-                    sourceParameter.getName(),
-                    new NullPresenceCheck( sourceParameter.getName() )
-                );
-            }
         }
         for ( PropertyMapping mapping : propertyMappings ) {
             if ( mapping.isConstructorMapping() ) {

processor/src/main/java/org/mapstruct/ap/internal/model/PresenceCheckMethodResolver.java

@@ -9,6 +9,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.stream.Collectors;
 
+import org.mapstruct.ap.internal.gem.ConditionStrategyGem;
 import org.mapstruct.ap.internal.model.common.Parameter;
 import org.mapstruct.ap.internal.model.common.PresenceCheck;
 import org.mapstruct.ap.internal.model.source.Method;
@@ -18,6 +19,7 @@ import org.mapstruct.ap.internal.model.source.SourceMethod;
 import org.mapstruct.ap.internal.model.source.selector.MethodSelectors;
 import org.mapstruct.ap.internal.model.source.selector.SelectedMethod;
 import org.mapstruct.ap.internal.model.source.selector.SelectionContext;
+import org.mapstruct.ap.internal.model.source.selector.SelectionCriteria;
 import org.mapstruct.ap.internal.util.Message;
 
 /**
@@ -34,38 +36,12 @@ public final class PresenceCheckMethodResolver {
         SelectionParameters selectionParameters,
         MappingBuilderContext ctx
     ) {
-        SelectedMethod<SourceMethod> matchingMethod = findMatchingPresenceCheckMethod(
+        List<SelectedMethod<SourceMethod>> matchingMethods = findMatchingMethods(
             method,
-            selectionParameters,
+            SelectionContext.forPresenceCheckMethods( method, selectionParameters, ctx.getTypeFactory() ),
             ctx
         );
 
-        if ( matchingMethod == null ) {
-            return null;
-        }
-
-        MethodReference methodReference = getPresenceCheckMethodReference( method, matchingMethod, ctx );
-
-        return new MethodReferencePresenceCheck( methodReference );
-
-    }
-
-    private static SelectedMethod<SourceMethod> findMatchingPresenceCheckMethod(
-        Method method,
-        SelectionParameters selectionParameters,
-        MappingBuilderContext ctx
-    ) {
-        MethodSelectors selectors = new MethodSelectors(
-            ctx.getTypeUtils(),
-            ctx.getElementUtils(),
-            ctx.getMessager()
-        );
-
-        List<SelectedMethod<SourceMethod>> matchingMethods = selectors.getMatchingMethods(
-            getAllAvailableMethods( method, ctx.getSourceModel() ),
-            SelectionContext.forPresenceCheckMethods( method, selectionParameters, ctx.getTypeFactory() )
-        );
-
         if ( matchingMethods.isEmpty() ) {
             return null;
         }
@@ -84,7 +60,72 @@ public final class PresenceCheckMethodResolver {
             return null;
         }
 
-        return matchingMethods.get( 0 );
+        SelectedMethod<SourceMethod> matchingMethod = matchingMethods.get( 0 );
+
+        MethodReference methodReference = getPresenceCheckMethodReference( method, matchingMethod, ctx );
+
+        return new MethodReferencePresenceCheck( methodReference );
+
+    }
+
+    public static PresenceCheck getPresenceCheckForSourceParameter(
+        Method method,
+        SelectionParameters selectionParameters,
+        Parameter sourceParameter,
+        MappingBuilderContext ctx
+    ) {
+        List<SelectedMethod<SourceMethod>> matchingMethods = findMatchingMethods(
+            method,
+            SelectionContext.forSourceParameterPresenceCheckMethods(
+                method,
+                selectionParameters,
+                sourceParameter,
+                ctx.getTypeFactory()
+            ),
+            ctx
+        );
+
+        if ( matchingMethods.isEmpty() ) {
+            return null;
+        }
+
+        if ( matchingMethods.size() > 1 ) {
+            ctx.getMessager().printMessage(
+                method.getExecutable(),
+                Message.GENERAL_AMBIGUOUS_SOURCE_PARAMETER_CHECK_METHOD,
+                sourceParameter.getType().describe(),
+                matchingMethods.stream()
+                    .map( SelectedMethod::getMethod )
+                    .map( Method::describe )
+                    .collect( Collectors.joining( ", " ) )
+            );
+
+            return null;
+        }
+
+        SelectedMethod<SourceMethod> matchingMethod = matchingMethods.get( 0 );
+
+        MethodReference methodReference = getPresenceCheckMethodReference( method, matchingMethod, ctx );
+
+        return new MethodReferencePresenceCheck( methodReference );
+
+    }
+
+    private static List<SelectedMethod<SourceMethod>> findMatchingMethods(
+        Method method,
+        SelectionContext selectionContext,
+        MappingBuilderContext ctx
+    ) {
+        MethodSelectors selectors = new MethodSelectors(
+            ctx.getTypeUtils(),
+            ctx.getElementUtils(),
+            ctx.getMessager()
+        );
+
+        return selectors.getMatchingMethods(
+            getAllAvailableMethods( method, ctx.getSourceModel(), selectionContext.getSelectionCriteria() ),
+            selectionContext
+        );
     }
 
     private static MethodReference getPresenceCheckMethodReference(
@@ -116,7 +157,8 @@ public final class PresenceCheckMethodResolver {
         }
     }
 
-    private static List<SourceMethod> getAllAvailableMethods(Method method, List<SourceMethod> sourceModelMethods) {
+    private static List<SourceMethod> getAllAvailableMethods(Method method, List<SourceMethod> sourceModelMethods,
+                                                             SelectionCriteria selectionCriteria) {
         ParameterProvidedMethods contextProvidedMethods = method.getContextProvidedMethods();
         if ( contextProvidedMethods.isEmpty() ) {
             return sourceModelMethods;
@@ -129,9 +171,19 @@ public final class PresenceCheckMethodResolver {
             new ArrayList<>( methodsProvidedByParams.size() + sourceModelMethods.size() );
 
         for ( SourceMethod methodProvidedByParams : methodsProvidedByParams ) {
-            // add only methods from context that do have the @Condition annotation
+            if ( selectionCriteria.isPresenceCheckRequired() ) {
-            if ( methodProvidedByParams.isPresenceCheck() ) {
+                // add only methods from context that do have the @Condition for properties annotation
-                availableMethods.add( methodProvidedByParams );
+                if ( methodProvidedByParams.getConditionOptions()
+                    .isStrategyApplicable( ConditionStrategyGem.PROPERTIES ) ) {
+                    availableMethods.add( methodProvidedByParams );
+                }
+            }
+            else if ( selectionCriteria.isSourceParameterCheckRequired() ) {
+                // add only methods from context that do have the @Condition for source parameters annotation
+                if ( methodProvidedByParams.getConditionOptions()
+                    .isStrategyApplicable( ConditionStrategyGem.SOURCE_PARAMETERS ) ) {
+                    availableMethods.add( methodProvidedByParams );
+                }
             }
         }
         availableMethods.addAll( sourceModelMethods );

processor/src/main/java/org/mapstruct/ap/internal/model/common/Parameter.java

@@ -133,6 +133,14 @@ public class Parameter extends ModelElement {
         return varArgs;
     }
 
+    public boolean isSourceParameter() {
+        return !isMappingTarget() &&
+            !isTargetType() &&
+            !isMappingContext() &&
+            !isSourcePropertyName() &&
+            !isTargetPropertyName();
+    }
+
     @Override
     public int hashCode() {
         int result = name != null ? name.hashCode() : 0;
@@ -224,12 +232,4 @@ public class Parameter extends ModelElement {
       return parameters.stream().filter( Parameter::isTargetPropertyName ).findAny().orElse( null );
     }
 
-    private static boolean isSourceParameter( Parameter parameter ) {
-        return !parameter.isMappingTarget() &&
-               !parameter.isTargetType() &&
-               !parameter.isMappingContext() &&
-               !parameter.isSourcePropertyName() &&
-               !parameter.isTargetPropertyName();
-    }
-
 }

processor/src/main/java/org/mapstruct/ap/internal/model/common/ParameterBinding.java

@@ -6,7 +6,9 @@
 package org.mapstruct.ap.internal.model.common;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
+import java.util.EnumSet;
 import java.util.List;
 import java.util.Set;
 
@@ -19,23 +21,14 @@ public class ParameterBinding {
 
     private final Type type;
     private final String variableName;
-    private final boolean targetType;
-    private final boolean mappingTarget;
-    private final boolean mappingContext;
-    private final boolean sourcePropertyName;
-    private final boolean targetPropertyName;
     private final SourceRHS sourceRHS;
+    private final Collection<BindingType> bindingTypes;
 
-    private ParameterBinding(Type parameterType, String variableName, boolean mappingTarget, boolean targetType,
+    private ParameterBinding(Type parameterType, String variableName, Collection<BindingType> bindingTypes,
-                             boolean mappingContext, boolean sourcePropertyName, boolean targetPropertyName,
                              SourceRHS sourceRHS) {
         this.type = parameterType;
         this.variableName = variableName;
-        this.targetType = targetType;
+        this.bindingTypes = bindingTypes;
-        this.mappingTarget = mappingTarget;
-        this.mappingContext = mappingContext;
-        this.sourcePropertyName = sourcePropertyName;
-        this.targetPropertyName = targetPropertyName;
         this.sourceRHS = sourceRHS;
     }
 
@@ -46,39 +39,47 @@ public class ParameterBinding {
         return variableName;
     }
 
+    public boolean isSourceParameter() {
+        return bindingTypes.contains( BindingType.PARAMETER );
+    }
+
     /**
      * @return {@code true}, if the parameter being bound is a {@code @TargetType} parameter.
      */
     public boolean isTargetType() {
-        return targetType;
+        return bindingTypes.contains( BindingType.TARGET_TYPE );
     }
 
     /**
      * @return {@code true}, if the parameter being bound is a {@code @MappingTarget} parameter.
      */
     public boolean isMappingTarget() {
-        return mappingTarget;
+        return bindingTypes.contains( BindingType.MAPPING_TARGET );
     }
 
     /**
      * @return {@code true}, if the parameter being bound is a {@code @MappingContext} parameter.
      */
     public boolean isMappingContext() {
-        return mappingContext;
+        return bindingTypes.contains( BindingType.CONTEXT );
+    }
+
+    public boolean isForSourceRhs() {
+        return bindingTypes.contains( BindingType.SOURCE_RHS );
     }
 
     /**
      * @return {@code true}, if the parameter being bound is a {@code @SourcePropertyName} parameter.
      */
     public boolean isSourcePropertyName() {
-        return sourcePropertyName;
+        return bindingTypes.contains( BindingType.SOURCE_PROPERTY_NAME );
     }
 
     /**
      * @return {@code true}, if the parameter being bound is a {@code @TargetPropertyName} parameter.
      */
     public boolean isTargetPropertyName() {
-        return targetPropertyName;
+        return bindingTypes.contains( BindingType.TARGET_PROPERTY_NAME );
     }
 
     /**
@@ -96,7 +97,7 @@ public class ParameterBinding {
     }
 
     public Set<Type> getImportTypes() {
-        if ( targetType ) {
+        if ( isTargetType() ) {
             return type.getImportTypes();
         }
 
@@ -112,14 +113,31 @@ public class ParameterBinding {
      * @return a parameter binding reflecting the given parameter as being used as argument for a method call
      */
     public static ParameterBinding fromParameter(Parameter parameter) {
+        EnumSet<BindingType> bindingTypes = EnumSet.of( BindingType.PARAMETER );
+        if ( parameter.isMappingTarget() ) {
+            bindingTypes.add( BindingType.MAPPING_TARGET );
+        }
+
+        if ( parameter.isTargetType() ) {
+            bindingTypes.add( BindingType.TARGET_TYPE );
+        }
+
+        if ( parameter.isMappingContext() ) {
+            bindingTypes.add( BindingType.CONTEXT );
+        }
+
+        if ( parameter.isSourcePropertyName() ) {
+            bindingTypes.add( BindingType.SOURCE_PROPERTY_NAME );
+        }
+
+        if ( parameter.isTargetPropertyName() ) {
+            bindingTypes.add( BindingType.TARGET_PROPERTY_NAME );
+        }
+
         return new ParameterBinding(
             parameter.getType(),
             parameter.getName(),
-            parameter.isMappingTarget(),
+            bindingTypes,
-            parameter.isTargetType(),
-            parameter.isMappingContext(),
-            parameter.isSourcePropertyName(),
-            parameter.isTargetPropertyName(),
             null
         );
     }
@@ -136,11 +154,7 @@ public class ParameterBinding {
         return new ParameterBinding(
             parameterType,
             parameterName,
-            false,
+            Collections.emptySet(),
-            false,
-            false,
-            false,
-            false,
             null
         );
     }
@@ -150,21 +164,31 @@ public class ParameterBinding {
      * @return a parameter binding representing a target type parameter
      */
     public static ParameterBinding forTargetTypeBinding(Type classTypeOf) {
-        return new ParameterBinding( classTypeOf, null, false, true, false, false, false, null );
+        return new ParameterBinding( classTypeOf, null, Collections.singleton( BindingType.TARGET_TYPE ), null );
     }
 
     /**
      * @return a parameter binding representing a target property name parameter
      */
     public static ParameterBinding forTargetPropertyNameBinding(Type classTypeOf) {
-        return new ParameterBinding( classTypeOf, null, false, false, false, false, true, null );
+        return new ParameterBinding(
+            classTypeOf,
+            null,
+            Collections.singleton( BindingType.TARGET_PROPERTY_NAME ),
+            null
+        );
     }
 
     /**
      * @return a parameter binding representing a source property name parameter
      */
     public static ParameterBinding forSourcePropertyNameBinding(Type classTypeOf) {
-        return new ParameterBinding( classTypeOf, null, false, false, false, true, false, null );
+        return new ParameterBinding(
+            classTypeOf,
+            null,
+            Collections.singleton( BindingType.SOURCE_PROPERTY_NAME ),
+            null
+        );
     }
 
     /**
@@ -172,7 +196,7 @@ public class ParameterBinding {
      * @return a parameter binding representing a mapping target parameter
      */
     public static ParameterBinding forMappingTargetBinding(Type resultType) {
-        return new ParameterBinding( resultType, null, true, false, false, false, false, null );
+        return new ParameterBinding( resultType, null, Collections.singleton( BindingType.MAPPING_TARGET ), null );
     }
 
     /**
@@ -180,10 +204,27 @@ public class ParameterBinding {
      * @return a parameter binding representing a mapping source type
      */
     public static ParameterBinding forSourceTypeBinding(Type sourceType) {
-        return new ParameterBinding( sourceType, null, false, false, false, false, false, null );
+        return new ParameterBinding( sourceType, null, Collections.singleton( BindingType.SOURCE_TYPE ), null );
     }
 
     public static ParameterBinding fromSourceRHS(SourceRHS sourceRHS) {
-        return new ParameterBinding( sourceRHS.getSourceType(), null, false, false, false, false, false, sourceRHS );
+        return new ParameterBinding(
+            sourceRHS.getSourceType(),
+            null,
+            Collections.singleton( BindingType.SOURCE_RHS ),
+            sourceRHS
+        );
+    }
+
+    enum BindingType {
+        PARAMETER,
+        FROM_TYPE_AND_NAME,
+        TARGET_TYPE,
+        TARGET_PROPERTY_NAME,
+        SOURCE_PROPERTY_NAME,
+        MAPPING_TARGET,
+        CONTEXT,
+        SOURCE_TYPE,
+        SOURCE_RHS
     }
 }

processor/src/main/java/org/mapstruct/ap/internal/model/source/ConditionMethodOptions.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.internal.model.source;
+
+import java.util.Collection;
+import java.util.Collections;
+
+import org.mapstruct.ap.internal.gem.ConditionStrategyGem;
+
+/**
+ * Encapsulates all options specific for a condition check method.
+ *
+ * @author Filip Hrisafov
+ */
+public class ConditionMethodOptions {
+
+    private static final ConditionMethodOptions EMPTY = new ConditionMethodOptions( Collections.emptyList() );
+
+    private final Collection<ConditionOptions> conditionOptions;
+
+    public ConditionMethodOptions(Collection<ConditionOptions> conditionOptions) {
+        this.conditionOptions = conditionOptions;
+    }
+
+    public boolean isStrategyApplicable(ConditionStrategyGem strategy) {
+        for ( ConditionOptions conditionOption : conditionOptions ) {
+            if ( conditionOption.getConditionStrategies().contains( strategy ) ) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    public boolean isAnyStrategyApplicable() {
+        return !conditionOptions.isEmpty();
+    }
+
+    public static ConditionMethodOptions empty() {
+        return EMPTY;
+    }
+}

processor/src/main/java/org/mapstruct/ap/internal/model/source/ConditionOptions.java

@@ -0,0 +1,170 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.internal.model.source;
+
+import java.util.Collection;
+import java.util.EnumSet;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+import javax.lang.model.element.ExecutableElement;
+import javax.lang.model.element.TypeElement;
+import javax.lang.model.type.DeclaredType;
+import javax.lang.model.type.TypeKind;
+import javax.lang.model.type.TypeMirror;
+
+import org.mapstruct.ap.internal.gem.ConditionGem;
+import org.mapstruct.ap.internal.gem.ConditionStrategyGem;
+import org.mapstruct.ap.internal.model.common.Parameter;
+import org.mapstruct.ap.internal.util.FormattingMessager;
+import org.mapstruct.ap.internal.util.Message;
+
+/**
+ * @author Filip Hrisafov
+ */
+public class ConditionOptions {
+
+    private final Set<ConditionStrategyGem> conditionStrategies;
+
+    private ConditionOptions(Set<ConditionStrategyGem> conditionStrategies) {
+        this.conditionStrategies = conditionStrategies;
+    }
+
+    public Collection<ConditionStrategyGem> getConditionStrategies() {
+        return conditionStrategies;
+    }
+
+    public static ConditionOptions getInstanceOn(ConditionGem condition, ExecutableElement method,
+                                                 List<Parameter> parameters,
+                                                 FormattingMessager messager) {
+        if ( condition == null ) {
+            return null;
+        }
+
+        TypeMirror returnType = method.getReturnType();
+        TypeKind returnTypeKind = returnType.getKind();
+        // We only allow methods that return boolean or Boolean to be condition methods
+        if ( returnTypeKind != TypeKind.BOOLEAN ) {
+            if ( returnTypeKind != TypeKind.DECLARED ) {
+                return null;
+            }
+            DeclaredType declaredType = (DeclaredType) returnType;
+            TypeElement returnTypeElement = (TypeElement) declaredType.asElement();
+            if ( !returnTypeElement.getQualifiedName().contentEquals( Boolean.class.getCanonicalName() ) ) {
+                return null;
+            }
+        }
+
+        Set<ConditionStrategyGem> strategies = condition.appliesTo().get()
+            .stream()
+            .map( ConditionStrategyGem::valueOf )
+            .collect( Collectors.toCollection( () -> EnumSet.noneOf( ConditionStrategyGem.class ) ) );
+
+        if ( strategies.isEmpty() ) {
+            messager.printMessage(
+                method,
+                condition.mirror(),
+                condition.appliesTo().getAnnotationValue(),
+                Message.CONDITION_MISSING_APPLIES_TO_STRATEGY
+            );
+
+            return null;
+        }
+
+        boolean allStrategiesValid = true;
+
+        for ( ConditionStrategyGem strategy : strategies ) {
+            boolean isStrategyValid = isValid( strategy, condition, method, parameters, messager );
+            allStrategiesValid &= isStrategyValid;
+        }
+
+        return allStrategiesValid ? new ConditionOptions( strategies ) : null;
+    }
+
+    protected static boolean isValid(ConditionStrategyGem strategy, ConditionGem condition,
+                                     ExecutableElement method, List<Parameter> parameters,
+                                     FormattingMessager messager) {
+        if ( strategy == ConditionStrategyGem.SOURCE_PARAMETERS ) {
+            return hasValidStrategyForSourceProperties( condition, method, parameters, messager );
+        }
+        else if ( strategy == ConditionStrategyGem.PROPERTIES ) {
+            return hasValidStrategyForProperties( condition, method, parameters, messager );
+        }
+        else {
+            throw new IllegalStateException( "Invalid condition strategy: " + strategy );
+        }
+    }
+
+    protected static boolean hasValidStrategyForSourceProperties(ConditionGem condition, ExecutableElement method,
+                                                                 List<Parameter> parameters,
+                                                                 FormattingMessager messager) {
+        for ( Parameter parameter : parameters ) {
+            if ( parameter.isSourceParameter() ) {
+                // source parameter is a valid parameter for a source condition check
+                continue;
+            }
+
+            if ( parameter.isMappingContext() ) {
+                // mapping context parameter is a valid parameter for a source condition check
+                continue;
+            }
+
+            messager.printMessage(
+                method,
+                condition.mirror(),
+                Message.CONDITION_SOURCE_PARAMETERS_INVALID_PARAMETER,
+                parameter.describe()
+            );
+            return false;
+        }
+        return true;
+    }
+
+    protected static boolean hasValidStrategyForProperties(ConditionGem condition, ExecutableElement method,
+                                                           List<Parameter> parameters,
+                                                           FormattingMessager messager) {
+        for ( Parameter parameter : parameters ) {
+            if ( parameter.isSourceParameter() ) {
+                // source parameter is a valid parameter for a property condition check
+                continue;
+            }
+
+            if ( parameter.isMappingContext() ) {
+                // mapping context parameter is a valid parameter for a property condition check
+                continue;
+            }
+
+            if ( parameter.isTargetType() ) {
+                // target type parameter is a valid parameter for a property condition check
+                continue;
+            }
+
+            if ( parameter.isMappingTarget() ) {
+                // mapping target parameter is a valid parameter for a property condition check
+                continue;
+            }
+
+            if ( parameter.isSourcePropertyName() ) {
+                // source property name parameter is a valid parameter for a property condition check
+                continue;
+            }
+
+            if ( parameter.isTargetPropertyName() ) {
+                // target property name parameter is a valid parameter for a property condition check
+                continue;
+            }
+
+            messager.printMessage(
+                method,
+                condition.mirror(),
+                Message.CONDITION_PROPERTIES_INVALID_PARAMETER,
+                parameter
+            );
+            return false;
+        }
+        return true;
+    }
+}

processor/src/main/java/org/mapstruct/ap/internal/model/source/Method.java

@@ -90,14 +90,6 @@ public interface Method {
      */
     boolean isObjectFactory();
 
-    /**
-     * Returns whether the method is designated as a presence check method
-     * @return {@code true} if it is a presence check method
-     */
-    default boolean isPresenceCheck() {
-        return false;
-    }
-
     /**
      * Returns the parameter designated as target type (if present) {@link org.mapstruct.TargetType }
      *
@@ -187,6 +179,10 @@ public interface Method {
      */
     MappingMethodOptions getOptions();
 
+    default ConditionMethodOptions getConditionOptions() {
+        return ConditionMethodOptions.empty();
+    }
+
     /**
      *
      * @return true when @MappingTarget annotated parameter is the same type as the return type. The method has

processor/src/main/java/org/mapstruct/ap/internal/model/source/SourceMethod.java

@@ -15,7 +15,6 @@ import javax.lang.model.element.Element;
 import javax.lang.model.element.ExecutableElement;
 import javax.lang.model.element.Modifier;
 
-import org.mapstruct.ap.internal.gem.ConditionGem;
 import org.mapstruct.ap.internal.gem.ObjectFactoryGem;
 import org.mapstruct.ap.internal.model.common.Accessibility;
 import org.mapstruct.ap.internal.model.common.Parameter;
@@ -50,11 +49,11 @@ public class SourceMethod implements Method {
     private final Parameter sourcePropertyNameParameter;
     private final Parameter targetPropertyNameParameter;
     private final boolean isObjectFactory;
-    private final boolean isPresenceCheck;
     private final Type returnType;
     private final Accessibility accessibility;
     private final List<Type> exceptionTypes;
     private final MappingMethodOptions mappingMethodOptions;
+    private final ConditionMethodOptions conditionMethodOptions;
     private final List<SourceMethod> prototypeMethods;
     private final Type mapperToImplement;
 
@@ -95,6 +94,7 @@ public class SourceMethod implements Method {
         private List<ValueMappingOptions> valueMappings;
         private EnumMappingOptions enumMappingOptions;
         private ParameterProvidedMethods contextProvidedMethods;
+        private Set<ConditionOptions> conditionOptions;
         private List<Type> typeParameters;
         private Set<SubclassMappingOptions> subclassMappings;
 
@@ -196,6 +196,11 @@ public class SourceMethod implements Method {
             return this;
         }
 
+        public Builder setConditionOptions(Set<ConditionOptions> conditionOptions) {
+            this.conditionOptions = conditionOptions;
+            return this;
+        }
+
         public Builder setVerboseLogging(boolean verboseLogging) {
             this.verboseLogging = verboseLogging;
             return this;
@@ -223,17 +228,22 @@ public class SourceMethod implements Method {
                 subclassValidator
             );
 
+            ConditionMethodOptions conditionMethodOptions =
+                conditionOptions != null ? new ConditionMethodOptions( conditionOptions ) :
+                    ConditionMethodOptions.empty();
+
             this.typeParameters = this.executable.getTypeParameters()
                 .stream()
                 .map( Element::asType )
                 .map( typeFactory::getType )
                 .collect( Collectors.toList() );
 
-            return new SourceMethod( this, mappingMethodOptions );
+            return new SourceMethod( this, mappingMethodOptions, conditionMethodOptions );
         }
     }
 
-    private SourceMethod(Builder builder, MappingMethodOptions mappingMethodOptions) {
+    private SourceMethod(Builder builder, MappingMethodOptions mappingMethodOptions,
+                         ConditionMethodOptions conditionMethodOptions) {
         this.declaringMapper = builder.declaringMapper;
         this.executable = builder.executable;
         this.parameters = builder.parameters;
@@ -242,6 +252,7 @@ public class SourceMethod implements Method {
         this.accessibility = Accessibility.fromModifiers( builder.executable.getModifiers() );
 
         this.mappingMethodOptions = mappingMethodOptions;
+        this.conditionMethodOptions = conditionMethodOptions;
 
         this.sourceParameters = Parameter.getSourceParameters( parameters );
         this.contextParameters = Parameter.getContextParameters( parameters );
@@ -254,7 +265,6 @@ public class SourceMethod implements Method {
         this.targetPropertyNameParameter = Parameter.getTargetPropertyNameParameter( parameters );
         this.hasObjectFactoryAnnotation = ObjectFactoryGem.instanceOn( executable ) != null;
         this.isObjectFactory = determineIfIsObjectFactory();
-        this.isPresenceCheck = determineIfIsPresenceCheck();
 
         this.typeUtils = builder.typeUtils;
         this.typeFactory = builder.typeFactory;
@@ -274,19 +284,6 @@ public class SourceMethod implements Method {
             && ( hasObjectFactoryAnnotation || hasNoSourceParameters );
     }
 
-    private boolean determineIfIsPresenceCheck() {
-        if ( returnType.isPrimitive() ) {
-            if ( !returnType.getName().equals( "boolean" ) ) {
-                return false;
-            }
-        }
-        else if ( !returnType.getFullyQualifiedName().equals( Boolean.class.getCanonicalName() ) ) {
-            return false;
-        }
-
-        return ConditionGem.instanceOn( executable ) != null;
-    }
-
     @Override
     public Type getDeclaringMapper() {
         return declaringMapper;
@@ -547,6 +544,11 @@ public class SourceMethod implements Method {
         return mappingMethodOptions;
     }
 
+    @Override
+    public ConditionMethodOptions getConditionOptions() {
+        return conditionMethodOptions;
+    }
+
     @Override
     public boolean isStatic() {
         return executable.getModifiers().contains( Modifier.STATIC );
@@ -567,11 +569,6 @@ public class SourceMethod implements Method {
         return Executables.isLifecycleCallbackMethod( getExecutable() );
     }
 
-    @Override
-    public boolean isPresenceCheck() {
-        return isPresenceCheck;
-    }
-
     public boolean isAfterMappingMethod() {
         return Executables.isAfterMappingMethod( getExecutable() );
     }

processor/src/main/java/org/mapstruct/ap/internal/model/source/selector/CreateOrUpdateSelector.java

@@ -32,6 +32,7 @@ public class CreateOrUpdateSelector implements MethodSelector {
                                                                          SelectionContext context) {
         SelectionCriteria criteria = context.getSelectionCriteria();
         if ( criteria.isLifecycleCallbackRequired() || criteria.isObjectFactoryRequired()
+            || criteria.isSourceParameterCheckRequired()
             || criteria.isPresenceCheckRequired() ) {
             return methods;
         }

processor/src/main/java/org/mapstruct/ap/internal/model/source/selector/MethodFamilySelector.java

@@ -8,6 +8,7 @@ package org.mapstruct.ap.internal.model.source.selector;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.mapstruct.ap.internal.gem.ConditionStrategyGem;
 import org.mapstruct.ap.internal.model.source.Method;
 
 /**
@@ -25,9 +26,22 @@ public class MethodFamilySelector implements MethodSelector {
 
         List<SelectedMethod<T>> result = new ArrayList<>( methods.size() );
         for ( SelectedMethod<T> method : methods ) {
-            if ( method.getMethod().isObjectFactory() == criteria.isObjectFactoryRequired()
+            if ( criteria.isPresenceCheckRequired() ) {
+                if ( method.getMethod()
+                    .getConditionOptions()
+                    .isStrategyApplicable( ConditionStrategyGem.PROPERTIES ) ) {
+                    result.add( method );
+                }
+            }
+            else if ( criteria.isSourceParameterCheckRequired() ) {
+                if ( method.getMethod()
+                    .getConditionOptions()
+                    .isStrategyApplicable( ConditionStrategyGem.SOURCE_PARAMETERS ) ) {
+                    result.add( method );
+                }
+            }
+            else if ( method.getMethod().isObjectFactory() == criteria.isObjectFactoryRequired()
                 && method.getMethod().isLifecycleCallbackMethod() == criteria.isLifecycleCallbackRequired()
-                && method.getMethod().isPresenceCheck() == criteria.isPresenceCheckRequired()
             ) {
 
                 result.add( method );

processor/src/main/java/org/mapstruct/ap/internal/model/source/selector/SelectionContext.java

@@ -163,6 +163,45 @@ public class SelectionContext {
         );
     }
 
+    public static SelectionContext forSourceParameterPresenceCheckMethods(Method mappingMethod,
+                                                                          SelectionParameters selectionParameters,
+                                                                          Parameter sourceParameter,
+                                                                          TypeFactory typeFactory) {
+        SelectionCriteria criteria = SelectionCriteria.forSourceParameterCheckMethods( selectionParameters );
+        Type booleanType = typeFactory.getType( Boolean.class );
+        return new SelectionContext(
+            null,
+            criteria,
+            mappingMethod,
+            booleanType,
+            booleanType,
+            () -> getParameterBindingsForSourceParameterPresenceCheck(
+                mappingMethod,
+                booleanType,
+                sourceParameter,
+                typeFactory
+            )
+        );
+    }
+
+    private static List<ParameterBinding> getParameterBindingsForSourceParameterPresenceCheck(Method method,
+                                                                                              Type targetType,
+                                                                                              Parameter sourceParameter,
+                                                                                              TypeFactory typeFactory) {
+
+        List<ParameterBinding> availableParams = new ArrayList<>( method.getParameters().size() + 3 );
+
+        availableParams.add( ParameterBinding.fromParameter( sourceParameter ) );
+        availableParams.add( ParameterBinding.forTargetTypeBinding( typeFactory.classTypeOf( targetType ) ) );
+        for ( Parameter parameter : method.getParameters() ) {
+            if ( !parameter.isSourceParameter( ) ) {
+                availableParams.add( ParameterBinding.fromParameter( parameter ) );
+            }
+        }
+
+        return availableParams;
+    }
+
     private static List<ParameterBinding> getAvailableParameterBindingsFromMethod(Method method, Type targetType,
                                                                                   SourceRHS sourceRHS,
                                                                                   TypeFactory typeFactory) {

processor/src/main/java/org/mapstruct/ap/internal/model/source/selector/SelectionCriteria.java

@@ -97,6 +97,13 @@ public class SelectionCriteria {
         return type == Type.PRESENCE_CHECK;
     }
 
+    /**
+     * @return {@code true} if source parameter check methods should be selected, {@code false} otherwise
+     */
+    public boolean isSourceParameterCheckRequired() {
+        return type == Type.SOURCE_PARAMETER_CHECK;
+    }
+
     public void setIgnoreQualifiers(boolean ignoreQualifiers) {
         this.ignoreQualifiers = ignoreQualifiers;
     }
@@ -177,6 +184,10 @@ public class SelectionCriteria {
         return new SelectionCriteria( selectionParameters, null, null, Type.PRESENCE_CHECK );
     }
 
+    public static SelectionCriteria forSourceParameterCheckMethods(SelectionParameters selectionParameters) {
+        return new SelectionCriteria( selectionParameters, null, null, Type.SOURCE_PARAMETER_CHECK );
+    }
+
     public static SelectionCriteria forSubclassMappingMethods(SelectionParameters selectionParameters,
         MappingControl mappingControl) {
         return new SelectionCriteria( selectionParameters, mappingControl, null, Type.SELF_NOT_ALLOWED );
@@ -187,6 +198,7 @@ public class SelectionCriteria {
         OBJECT_FACTORY,
         LIFECYCLE_CALLBACK,
         PRESENCE_CHECK,
+        SOURCE_PARAMETER_CHECK,
         SELF_NOT_ALLOWED,
     }
 }

processor/src/main/java/org/mapstruct/ap/internal/processor/MethodRetrievalProcessor.java

@@ -36,6 +36,7 @@ import org.mapstruct.ap.internal.model.common.Parameter;
 import org.mapstruct.ap.internal.model.common.Type;
 import org.mapstruct.ap.internal.model.common.TypeFactory;
 import org.mapstruct.ap.internal.model.source.BeanMappingOptions;
+import org.mapstruct.ap.internal.model.source.ConditionOptions;
 import org.mapstruct.ap.internal.model.source.EnumMappingOptions;
 import org.mapstruct.ap.internal.model.source.IterableMappingOptions;
 import org.mapstruct.ap.internal.model.source.MapMappingOptions;
@@ -53,6 +54,7 @@ import org.mapstruct.ap.internal.util.ElementUtils;
 import org.mapstruct.ap.internal.util.Executables;
 import org.mapstruct.ap.internal.util.FormattingMessager;
 import org.mapstruct.ap.internal.util.Message;
+import org.mapstruct.ap.internal.util.MetaAnnotations;
 import org.mapstruct.ap.internal.util.RepeatableAnnotations;
 import org.mapstruct.ap.internal.util.TypeUtils;
 import org.mapstruct.ap.spi.EnumTransformationStrategy;
@@ -73,6 +75,7 @@ public class MethodRetrievalProcessor implements ModelElementProcessor<Void, Lis
     private static final String SUB_CLASS_MAPPINGS_FQN = "org.mapstruct.SubclassMappings";
     private static final String VALUE_MAPPING_FQN = "org.mapstruct.ValueMapping";
     private static final String VALUE_MAPPINGS_FQN = "org.mapstruct.ValueMappings";
+    private static final String CONDITION_FQN = "org.mapstruct.Condition";
     private FormattingMessager messager;
     private TypeFactory typeFactory;
     private AccessorNamingUtils accessorNaming;
@@ -358,7 +361,7 @@ public class MethodRetrievalProcessor implements ModelElementProcessor<Void, Lis
             List<SourceMethod> contextProvidedMethods = new ArrayList<>( contextParamMethods.size() );
             for ( SourceMethod sourceMethod : contextParamMethods ) {
                 if ( sourceMethod.isLifecycleCallbackMethod() || sourceMethod.isObjectFactory()
-                    || sourceMethod.isPresenceCheck() ) {
+                    || sourceMethod.getConditionOptions().isAnyStrategyApplicable() ) {
                     contextProvidedMethods.add( sourceMethod );
                 }
             }
@@ -393,6 +396,7 @@ public class MethodRetrievalProcessor implements ModelElementProcessor<Void, Lis
             .setExceptionTypes( exceptionTypes )
             .setTypeUtils( typeUtils )
             .setTypeFactory( typeFactory )
+            .setConditionOptions( getConditionOptions( method, parameters ) )
             .setVerboseLogging( options.isVerbose() )
             .build();
     }
@@ -633,6 +637,18 @@ public class MethodRetrievalProcessor implements ModelElementProcessor<Void, Lis
                         .getProcessedAnnotations( method );
     }
 
+    /**
+     * Retrieves the conditions configured via {@code @Condition} from the given method.
+     *
+     * @param method     The method of interest
+     * @param parameters
+     * @return The condition options for the given method
+     */
+
+    private Set<ConditionOptions> getConditionOptions(ExecutableElement method, List<Parameter> parameters) {
+        return new MetaConditions( parameters ).getProcessedAnnotations( method );
+    }
+
     private class RepeatableMappings extends RepeatableAnnotations<MappingGem, MappingsGem, MappingOptions> {
         private BeanMappingOptions beanMappingOptions;
 
@@ -774,4 +790,32 @@ public class MethodRetrievalProcessor implements ModelElementProcessor<Void, Lis
             ValueMappingOptions.fromMappingsGem( gems, (ExecutableElement) source, messager, mappings );
         }
     }
+
+    private class MetaConditions extends MetaAnnotations<ConditionGem, ConditionOptions> {
+
+        protected final List<Parameter> parameters;
+
+        protected MetaConditions(List<Parameter> parameters) {
+            super( elementUtils, CONDITION_FQN );
+            this.parameters = parameters;
+        }
+
+        @Override
+        protected ConditionGem instanceOn(Element element) {
+            return ConditionGem.instanceOn( element );
+        }
+
+        @Override
+        protected void addInstance(ConditionGem gem, Element source, Set<ConditionOptions> values) {
+            ConditionOptions options = ConditionOptions.getInstanceOn(
+                gem,
+                (ExecutableElement) source,
+                parameters,
+                messager
+            );
+            if ( options != null ) {
+                values.add( options );
+            }
+        }
+    }
 }

processor/src/main/java/org/mapstruct/ap/internal/processor/creation/MappingResolverImpl.java

@@ -470,7 +470,7 @@ public class MappingResolverImpl implements MappingResolver {
         }
 
         private boolean isCandidateForMapping(Method methodCandidate) {
-            if ( methodCandidate.isPresenceCheck() ) {
+            if ( methodCandidate.getConditionOptions().isAnyStrategyApplicable() ) {
                 return false;
             }
             return isCreateMethodForMapping( methodCandidate ) || isUpdateMethodForMapping( methodCandidate );

processor/src/main/java/org/mapstruct/ap/internal/util/Message.java

@@ -46,6 +46,10 @@ public enum Message {
     BEANMAPPING_UNKNOWN_PROPERTY_IN_DEPENDS_ON( "\"%s\" is no property of the method return type." ),
     BEANMAPPING_IGNORE_BY_DEFAULT_WITH_MAPPING_TARGET_THIS( "Using @BeanMapping( ignoreByDefault = true ) with @Mapping( target = \".\", ... ) is not allowed. You'll need to explicitly ignore the target properties that should be ignored instead." ),
 
+    CONDITION_MISSING_APPLIES_TO_STRATEGY("'appliesTo' has to have at least one value in @Condition" ),
+    CONDITION_SOURCE_PARAMETERS_INVALID_PARAMETER("Parameter \"%s\" cannot be used with the ConditionStrategy#SOURCE_PARAMETERS. Only source and @Context parameters are allowed for conditions applicable to source parameters." ),
+    CONDITION_PROPERTIES_INVALID_PARAMETER("Parameter \"%s\" cannot be used with the ConditionStrategy#PROPERTIES. Only source, @Context, @MappingTarget, @TargetType, @TargetPropertyName and @SourcePropertyName parameters are allowed for conditions applicable to properties." ),
+
     PROPERTYMAPPING_MAPPING_NOTE( "mapping property: %s to: %s.", Diagnostic.Kind.NOTE ),
     PROPERTYMAPPING_CREATE_NOTE( "creating property mapping: %s.", Diagnostic.Kind.NOTE ),
     PROPERTYMAPPING_SELECT_NOTE( "selecting property mapping: %s.", Diagnostic.Kind.NOTE ),
@@ -143,6 +147,7 @@ public enum Message {
     GENERAL_AMBIGUOUS_MAPPING_METHOD( "Ambiguous mapping methods found for mapping %s to %s: %s. See " + FAQ_AMBIGUOUS_URL + " for more info." ),
     GENERAL_AMBIGUOUS_FACTORY_METHOD( "Ambiguous factory methods found for creating %s: %s. See " + FAQ_AMBIGUOUS_URL + " for more info." ),
     GENERAL_AMBIGUOUS_PRESENCE_CHECK_METHOD( "Ambiguous presence check methods found for checking %s: %s. See " + FAQ_AMBIGUOUS_URL + " for more info." ),
+    GENERAL_AMBIGUOUS_SOURCE_PARAMETER_CHECK_METHOD( "Ambiguous source parameter check methods found for checking %s: %s. See " + FAQ_AMBIGUOUS_URL + " for more info." ),
     GENERAL_AMBIGUOUS_CONSTRUCTORS( "Ambiguous constructors found for creating %s: %s. Either declare parameterless constructor or annotate the default constructor with an annotation named @Default." ),
     GENERAL_CONSTRUCTOR_PROPERTIES_NOT_MATCHING_PARAMETERS( "Incorrect @ConstructorProperties for %s. The size of the @ConstructorProperties does not match the number of constructor parameters" ),
     GENERAL_UNSUPPORTED_DATE_FORMAT_CHECK( "No dateFormat check is supported for types %s, %s" ),

processor/src/main/java/org/mapstruct/ap/internal/util/MetaAnnotations.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.internal.util;
+
+import java.util.HashSet;
+import java.util.LinkedHashSet;
+import java.util.Set;
+import javax.lang.model.element.AnnotationMirror;
+import javax.lang.model.element.Element;
+import javax.lang.model.element.ElementKind;
+import javax.lang.model.element.TypeElement;
+
+import org.mapstruct.tools.gem.Gem;
+
+/**
+ * @author Filip Hrisafov
+ */
+public abstract class MetaAnnotations<G extends Gem, V> {
+
+    private static final String JAVA_LANG_ANNOTATION_PGK = "java.lang.annotation";
+
+    private final ElementUtils elementUtils;
+    private final String annotationFqn;
+
+    protected MetaAnnotations(ElementUtils elementUtils, String annotationFqn) {
+        this.elementUtils = elementUtils;
+        this.annotationFqn = annotationFqn;
+    }
+
+    /**
+     * Retrieves the processed annotations.
+     *
+     * @param source The source element of interest
+     * @return The processed annotations for the given element
+     */
+    public Set<V> getProcessedAnnotations(Element source) {
+        return getValues( source, source, new LinkedHashSet<>(), new HashSet<>() );
+    }
+
+    protected abstract G instanceOn(Element element);
+
+    protected abstract void addInstance(G gem, Element source, Set<V> values);
+
+    /**
+     * Retrieves the processed annotations.
+     *
+     * @param source          The source element of interest
+     * @param element         Element of interest: method, or (meta) annotation
+     * @param values          the set of values found so far
+     * @param handledElements The collection of already handled elements to handle recursion correctly.
+     * @return The processed annotations for the given element
+     */
+    private Set<V> getValues(Element source, Element element, Set<V> values, Set<Element> handledElements) {
+        for ( AnnotationMirror annotationMirror : element.getAnnotationMirrors() ) {
+            Element annotationElement = annotationMirror.getAnnotationType().asElement();
+            if ( isAnnotation( annotationElement, annotationFqn ) ) {
+                G gem = instanceOn( element );
+                addInstance( gem, source, values );
+            }
+            else if ( isNotJavaAnnotation( element ) && !handledElements.contains( annotationElement ) ) {
+                handledElements.add( annotationElement );
+                getValues( source, annotationElement, values, handledElements );
+            }
+        }
+        return values;
+    }
+
+    private boolean isNotJavaAnnotation(Element element) {
+        if ( ElementKind.ANNOTATION_TYPE == element.getKind() ) {
+            return !elementUtils.getPackageOf( element ).getQualifiedName().contentEquals( JAVA_LANG_ANNOTATION_PGK );
+        }
+        return true;
+    }
+
+    private boolean isAnnotation(Element element, String annotationFqn) {
+        if ( ElementKind.ANNOTATION_TYPE == element.getKind() ) {
+            return ( (TypeElement) element ).getQualifiedName().contentEquals( annotationFqn );
+        }
+
+        return false;
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/conditional/basic/ConditionalMappingTest.java

@@ -208,6 +208,84 @@ public class ConditionalMappingTest {
             .containsExactly( "Test", "Test Vol. 2" );
     }
 
+    @ProcessorTest
+    @WithClasses({
+        ConditionalMethodForSourceBeanMapper.class
+    })
+    public void conditionalMethodForSourceBean() {
+        ConditionalMethodForSourceBeanMapper mapper = ConditionalMethodForSourceBeanMapper.INSTANCE;
+
+        ConditionalMethodForSourceBeanMapper.Employee employee = mapper.map(
+            new ConditionalMethodForSourceBeanMapper.EmployeeDto(
+                "1",
+                "Tester"
+            ) );
+
+        assertThat( employee ).isNotNull();
+        assertThat( employee.getId() ).isEqualTo( "1" );
+        assertThat( employee.getName() ).isEqualTo( "Tester" );
+
+        employee = mapper.map( null );
+
+        assertThat( employee ).isNull();
+
+        employee = mapper.map( new ConditionalMethodForSourceBeanMapper.EmployeeDto( null, "Tester" ) );
+
+        assertThat( employee ).isNull();
+
+        employee = mapper.map( new ConditionalMethodForSourceBeanMapper.EmployeeDto( "test-123", "Tester" ) );
+
+        assertThat( employee ).isNotNull();
+        assertThat( employee.getId() ).isEqualTo( "test-123" );
+        assertThat( employee.getName() ).isEqualTo( "Tester" );
+    }
+
+    @ProcessorTest
+    @WithClasses({
+        ConditionalMethodForSourceParameterAndPropertyMapper.class
+    })
+    public void conditionalMethodForSourceParameterAndProperty() {
+        ConditionalMethodForSourceParameterAndPropertyMapper mapper =
+            ConditionalMethodForSourceParameterAndPropertyMapper.INSTANCE;
+
+        ConditionalMethodForSourceParameterAndPropertyMapper.Employee employee = mapper.map(
+            new ConditionalMethodForSourceParameterAndPropertyMapper.EmployeeDto(
+                "1",
+                "Tester"
+            ) );
+
+        assertThat( employee ).isNotNull();
+        assertThat( employee.getId() ).isEqualTo( "1" );
+        assertThat( employee.getName() ).isEqualTo( "Tester" );
+        assertThat( employee.getManager() ).isNull();
+
+        employee = mapper.map( null );
+
+        assertThat( employee ).isNull();
+
+        employee = mapper.map( new ConditionalMethodForSourceParameterAndPropertyMapper.EmployeeDto(
+            "1",
+            "Tester",
+            new ConditionalMethodForSourceParameterAndPropertyMapper.EmployeeDto( null, "Manager" )
+        ) );
+
+        assertThat( employee ).isNotNull();
+        assertThat( employee.getManager() ).isNull();
+
+        employee = mapper.map( new ConditionalMethodForSourceParameterAndPropertyMapper.EmployeeDto(
+            "1",
+            "Tester",
+            new ConditionalMethodForSourceParameterAndPropertyMapper.EmployeeDto( "2", "Manager" )
+        ) );
+
+        assertThat( employee ).isNotNull();
+        assertThat( employee.getId() ).isEqualTo( "1" );
+        assertThat( employee.getName() ).isEqualTo( "Tester" );
+        assertThat( employee.getManager() ).isNotNull();
+        assertThat( employee.getManager().getId() ).isEqualTo( "2" );
+        assertThat( employee.getManager().getName() ).isEqualTo( "Manager" );
+    }
+
     @ProcessorTest
     @WithClasses({
         OptionalLikeConditionalMapper.class
@@ -244,4 +322,124 @@ public class ConditionalMappingTest {
 
         assertThat( targetEmployee.getName() ).isEqualTo( "CurrentName" );
     }
+
+    @ProcessorTest
+    @WithClasses({
+        ErroneousConditionalWithoutAppliesToMethodMapper.class
+    })
+    @ExpectedCompilationOutcome(
+        value = CompilationResult.FAILED,
+        diagnostics = {
+            @Diagnostic(
+                kind = javax.tools.Diagnostic.Kind.ERROR,
+                type = ErroneousConditionalWithoutAppliesToMethodMapper.class,
+                line = 19,
+                message = "'appliesTo' has to have at least one value in @Condition"
+            )
+        }
+    )
+    public void emptyConditional() {
+    }
+
+    @ProcessorTest
+    @WithClasses({
+        ErroneousSourceParameterConditionalWithMappingTargetMapper.class
+    })
+    @ExpectedCompilationOutcome(
+        value = CompilationResult.FAILED,
+        diagnostics = {
+            @Diagnostic(
+                kind = javax.tools.Diagnostic.Kind.ERROR,
+                type = ErroneousSourceParameterConditionalWithMappingTargetMapper.class,
+                line = 21,
+                message = "Parameter \"@MappingTarget BasicEmployee employee\"" +
+                    " cannot be used with the ConditionStrategy#SOURCE_PARAMETERS." +
+                    " Only source and @Context parameters are allowed for conditions applicable to source parameters."
+            )
+        }
+    )
+    public void sourceParameterConditionalWithMappingTarget() {
+    }
+
+    @ProcessorTest
+    @WithClasses({
+        ErroneousSourceParameterConditionalWithTargetTypeMapper.class
+    })
+    @ExpectedCompilationOutcome(
+        value = CompilationResult.FAILED,
+        diagnostics = {
+            @Diagnostic(
+                kind = javax.tools.Diagnostic.Kind.ERROR,
+                type = ErroneousSourceParameterConditionalWithTargetTypeMapper.class,
+                line = 21,
+                message = "Parameter \"@TargetType Class<?> targetClass\"" +
+                    " cannot be used with the ConditionStrategy#SOURCE_PARAMETERS." +
+                    " Only source and @Context parameters are allowed for conditions applicable to source parameters."
+            )
+        }
+    )
+    public void sourceParameterConditionalWithTargetType() {
+    }
+
+    @ProcessorTest
+    @WithClasses({
+        ErroneousSourceParameterConditionalWithTargetPropertyNameMapper.class
+    })
+    @ExpectedCompilationOutcome(
+        value = CompilationResult.FAILED,
+        diagnostics = {
+            @Diagnostic(
+                kind = javax.tools.Diagnostic.Kind.ERROR,
+                type = ErroneousSourceParameterConditionalWithTargetPropertyNameMapper.class,
+                line = 21,
+                message = "Parameter \"@TargetPropertyName String targetProperty\"" +
+                    " cannot be used with the ConditionStrategy#SOURCE_PARAMETERS." +
+                    " Only source and @Context parameters are allowed for conditions applicable to source parameters."
+            )
+        }
+    )
+    public void sourceParameterConditionalWithTargetPropertyName() {
+    }
+
+    @ProcessorTest
+    @WithClasses({
+        ErroneousSourceParameterConditionalWithSourcePropertyNameMapper.class
+    })
+    @ExpectedCompilationOutcome(
+        value = CompilationResult.FAILED,
+        diagnostics = {
+            @Diagnostic(
+                kind = javax.tools.Diagnostic.Kind.ERROR,
+                type = ErroneousSourceParameterConditionalWithSourcePropertyNameMapper.class,
+                line = 21,
+                message = "Parameter \"@SourcePropertyName String sourceProperty\"" +
+                    " cannot be used with the ConditionStrategy#SOURCE_PARAMETERS." +
+                    " Only source and @Context parameters are allowed for conditions applicable to source parameters."
+            )
+        }
+    )
+    public void sourceParametersConditionalWithSourcePropertyName() {
+    }
+
+    @ProcessorTest
+    @WithClasses({
+        ErroneousAmbiguousSourceParameterConditionalMethodMapper.class
+    })
+    @ExpectedCompilationOutcome(
+        value = CompilationResult.FAILED,
+        diagnostics = {
+            @Diagnostic(
+                kind = javax.tools.Diagnostic.Kind.ERROR,
+                type = ErroneousAmbiguousSourceParameterConditionalMethodMapper.class,
+                line = 17,
+                message = "Ambiguous source parameter check methods found for checking BasicEmployeeDto: " +
+                    "boolean hasName(BasicEmployeeDto value), " +
+                    "boolean hasStrategy(BasicEmployeeDto value). " +
+                    "See https://mapstruct.org/faq/#ambiguous for more info."
+            )
+        }
+    )
+    public void ambiguousSourceParameterConditionalMethod() {
+
+    }
 }

processor/src/test/java/org/mapstruct/ap/test/conditional/basic/ConditionalMethodForSourceBeanMapper.java

@@ -0,0 +1,64 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.conditional.basic;
+
+import org.mapstruct.Mapper;
+import org.mapstruct.SourceParameterCondition;
+import org.mapstruct.factory.Mappers;
+
+/**
+ * @author Filip Hrisafov
+ */
+@Mapper
+public interface ConditionalMethodForSourceBeanMapper {
+
+    ConditionalMethodForSourceBeanMapper INSTANCE = Mappers.getMapper( ConditionalMethodForSourceBeanMapper.class );
+
+    Employee map(EmployeeDto employee);
+
+    @SourceParameterCondition
+    default boolean canMapEmployeeDto(EmployeeDto employee) {
+        return employee != null && employee.getId() != null;
+    }
+
+    class EmployeeDto {
+
+        private final String id;
+        private final String name;
+
+        public EmployeeDto(String id, String name) {
+            this.id = id;
+            this.name = name;
+        }
+
+        public String getId() {
+            return id;
+        }
+
+        public String getName() {
+            return name;
+        }
+    }
+
+    class Employee {
+
+        private final String id;
+        private final String name;
+
+        public Employee(String id, String name) {
+            this.id = id;
+            this.name = name;
+        }
+
+        public String getId() {
+            return id;
+        }
+
+        public String getName() {
+            return name;
+        }
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/conditional/basic/ConditionalMethodForSourceParameterAndPropertyMapper.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.conditional.basic;
+
+import org.mapstruct.Condition;
+import org.mapstruct.ConditionStrategy;
+import org.mapstruct.Mapper;
+import org.mapstruct.factory.Mappers;
+
+/**
+ * @author Filip Hrisafov
+ */
+@Mapper
+public interface ConditionalMethodForSourceParameterAndPropertyMapper {
+
+    ConditionalMethodForSourceParameterAndPropertyMapper INSTANCE = Mappers.getMapper(
+        ConditionalMethodForSourceParameterAndPropertyMapper.class );
+
+    Employee map(EmployeeDto employee);
+
+    @Condition(appliesTo = {
+        ConditionStrategy.SOURCE_PARAMETERS,
+        ConditionStrategy.PROPERTIES
+    })
+    default boolean canMapEmployeeDto(EmployeeDto employee) {
+        return employee != null && employee.getId() != null;
+    }
+
+    class EmployeeDto {
+
+        private final String id;
+        private final String name;
+        private final EmployeeDto manager;
+
+        public EmployeeDto(String id, String name) {
+            this( id, name, null );
+        }
+
+        public EmployeeDto(String id, String name, EmployeeDto manager) {
+            this.id = id;
+            this.name = name;
+            this.manager = manager;
+        }
+
+        public String getId() {
+            return id;
+        }
+
+        public String getName() {
+            return name;
+        }
+
+        public EmployeeDto getManager() {
+            return manager;
+        }
+    }
+
+    class Employee {
+
+        private final String id;
+        private final String name;
+        private final Employee manager;
+
+        public Employee(String id, String name, Employee manager) {
+            this.id = id;
+            this.name = name;
+            this.manager = manager;
+        }
+
+        public String getId() {
+            return id;
+        }
+
+        public String getName() {
+            return name;
+        }
+
+        public Employee getManager() {
+            return manager;
+        }
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/conditional/basic/ErroneousAmbiguousSourceParameterConditionalMethodMapper.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.conditional.basic;
+
+import org.mapstruct.Mapper;
+import org.mapstruct.SourceParameterCondition;
+
+/**
+ * @author Filip Hrisafov
+ */
+@Mapper
+public interface ErroneousAmbiguousSourceParameterConditionalMethodMapper {
+
+    BasicEmployee map(BasicEmployeeDto employee);
+
+    @SourceParameterCondition
+    default boolean hasName(BasicEmployeeDto value) {
+        return value != null && value.getName() != null;
+    }
+
+    @SourceParameterCondition
+    default boolean hasStrategy(BasicEmployeeDto value) {
+        return value != null && value.getStrategy() != null;
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/conditional/basic/ErroneousConditionalWithoutAppliesToMethodMapper.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.conditional.basic;
+
+import org.mapstruct.Condition;
+import org.mapstruct.Mapper;
+
+/**
+ * @author Filip Hrisafov
+ */
+@Mapper
+public interface ErroneousConditionalWithoutAppliesToMethodMapper {
+
+    BasicEmployee map(BasicEmployeeDto employee);
+
+    @Condition(appliesTo = {})
+    default boolean isNotBlank(String value) {
+        return value != null && !value.trim().isEmpty();
+    }
+
+}

processor/src/test/java/org/mapstruct/ap/test/conditional/basic/ErroneousSourceParameterConditionalWithMappingTargetMapper.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.conditional.basic;
+
+import org.mapstruct.Condition;
+import org.mapstruct.ConditionStrategy;
+import org.mapstruct.Mapper;
+import org.mapstruct.MappingTarget;
+
+/**
+ * @author Filip Hrisafov
+ */
+@Mapper
+public interface ErroneousSourceParameterConditionalWithMappingTargetMapper {
+
+    BasicEmployee map(BasicEmployeeDto employee);
+
+    @Condition(appliesTo = ConditionStrategy.SOURCE_PARAMETERS)
+    default boolean isNotBlank(String value, @MappingTarget BasicEmployee employee) {
+        return value != null && !value.trim().isEmpty();
+    }
+
+}

processor/src/test/java/org/mapstruct/ap/test/conditional/basic/ErroneousSourceParameterConditionalWithSourcePropertyNameMapper.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.conditional.basic;
+
+import org.mapstruct.Condition;
+import org.mapstruct.ConditionStrategy;
+import org.mapstruct.Mapper;
+import org.mapstruct.SourcePropertyName;
+
+/**
+ * @author Filip Hrisafov
+ */
+@Mapper
+public interface ErroneousSourceParameterConditionalWithSourcePropertyNameMapper {
+
+    BasicEmployee map(BasicEmployeeDto employee);
+
+    @Condition(appliesTo = ConditionStrategy.SOURCE_PARAMETERS)
+    default boolean isNotBlank(String value, @SourcePropertyName String sourceProperty) {
+        return value != null && !value.trim().isEmpty();
+    }
+
+}

processor/src/test/java/org/mapstruct/ap/test/conditional/basic/ErroneousSourceParameterConditionalWithTargetPropertyNameMapper.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.conditional.basic;
+
+import org.mapstruct.Condition;
+import org.mapstruct.ConditionStrategy;
+import org.mapstruct.Mapper;
+import org.mapstruct.TargetPropertyName;
+
+/**
+ * @author Filip Hrisafov
+ */
+@Mapper
+public interface ErroneousSourceParameterConditionalWithTargetPropertyNameMapper {
+
+    BasicEmployee map(BasicEmployeeDto employee);
+
+    @Condition(appliesTo = ConditionStrategy.SOURCE_PARAMETERS)
+    default boolean isNotBlank(String value, @TargetPropertyName String targetProperty) {
+        return value != null && !value.trim().isEmpty();
+    }
+
+}

processor/src/test/java/org/mapstruct/ap/test/conditional/basic/ErroneousSourceParameterConditionalWithTargetTypeMapper.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.conditional.basic;
+
+import org.mapstruct.Condition;
+import org.mapstruct.ConditionStrategy;
+import org.mapstruct.Mapper;
+import org.mapstruct.TargetType;
+
+/**
+ * @author Filip Hrisafov
+ */
+@Mapper
+public interface ErroneousSourceParameterConditionalWithTargetTypeMapper {
+
+    BasicEmployee map(BasicEmployeeDto employee);
+
+    @Condition(appliesTo = ConditionStrategy.SOURCE_PARAMETERS)
+    default boolean isNotBlank(String value, @TargetType Class<?> targetClass) {
+        return value != null && !value.trim().isEmpty();
+    }
+
+}

processor/src/test/java/org/mapstruct/ap/test/gem/EnumGemsTest.java

@@ -11,12 +11,14 @@ import java.util.stream.Stream;
 
 import org.junit.jupiter.api.Test;
 import org.mapstruct.CollectionMappingStrategy;
+import org.mapstruct.ConditionStrategy;
 import org.mapstruct.InjectionStrategy;
 import org.mapstruct.MappingInheritanceStrategy;
 import org.mapstruct.NullValueCheckStrategy;
 import org.mapstruct.NullValueMappingStrategy;
 import org.mapstruct.ReportingPolicy;
 import org.mapstruct.ap.internal.gem.CollectionMappingStrategyGem;
+import org.mapstruct.ap.internal.gem.ConditionStrategyGem;
 import org.mapstruct.ap.internal.gem.InjectionStrategyGem;
 import org.mapstruct.ap.internal.gem.MappingInheritanceStrategyGem;
 import org.mapstruct.ap.internal.gem.NullValueCheckStrategyGem;
@@ -67,6 +69,12 @@ public class EnumGemsTest {
             namesOf( InjectionStrategyGem.values() ) );
     }
 
+    @Test
+    public void conditionStrategyGemIsCorrect() {
+        assertThat( namesOf( ConditionStrategy.values() ) ).isEqualTo(
+            namesOf( ConditionStrategyGem.values() ) );
+    }
+
     private static List<String> namesOf(Enum<?>[] values) {
         return Stream.of( values )
             .map( Enum::name )