Added docs

Author: marcingrzejszczak

src/main/antora/modules/ROOT/pages/appendix/custom-queries.adoc

@@ -367,8 +367,11 @@ If an entity has a relationship with the same type to different types of others
 If you need such a mapping and also have the need to work with those custom parameters, you have to unroll it accordingly.
 One way to do this are correlated subqueries (Neo4j 4.1+ required).
 
+[[custom-queries.expressions]]
+== Value Expressions in custom queries
+
 [[custom-queries.spel]]
-== Spring Expression Language in custom queries
+=== Spring Expression Language in custom queries
 
 {springdocsurl}/core/expressions.html[Spring Expression Language (SpEL)] can be used in custom queries inside `:#{}`.
 The colon here refers to a parameter and such an expression should be used where parameters make sense.
@@ -502,3 +505,18 @@ MATCH (n:`Bike`:`Gravel`:`Easy Trail`) WHERE n.id = $nameOrId OR n.name = $nameO
 
 Notice how we used standard parameter for the `nameOrId`: In most cases there is no need to complicate things here by
 adding a SpEL expression.
+
+
+[[custom-queries.propertyplaceholder]]
+=== Property Placeholder resolution in custom queries
+
+Spring's property placeholders can be used in custom queries inside `${}`.
+
+[source,java,indent=0]
+[[custom-queries-with-property-placeholder-example]]
+.ARepository.java
+----
+include::example$documentation/repositories/domain_events/ARepository.java[tags=property-placeholder]
+----
+
+In the example above, if the property `foo` would be set to `bar` then the `${foo}` block would be resolved to `bar`.

src/test/java/org/springframework/data/neo4j/documentation/repositories/domain_events/ARepository.java

@@ -36,6 +36,11 @@ public interface ARepository extends Neo4jRepository<AnAggregateRoot, String> {
 	Optional<AnAggregateRoot> findByCustomQuery(String name);
 	// end::standard-parameter[]
 
+	// tag::property-placeholder[]
+	@Query("MATCH (a:AnAggregateRoot) WHERE a.name = :${foo} RETURN a")
+	Optional<AnAggregateRoot> findByCustomQueryWithPropertyPlaceholder();
+	// end::property-placeholder[]
+
 	// tag::spel[]
 	@Query("MATCH (a:AnAggregateRoot) WHERE a.name = :#{#pt1 + #pt2} RETURN a")
 	Optional<AnAggregateRoot> findByCustomQueryWithSpEL(String pt1, String pt2);

src/test/java/org/springframework/data/neo4j/documentation/repositories/domain_events/DomainEventsTest.java

@@ -22,11 +22,13 @@
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.TestPropertySource;
 
 /**
  * Basic tests for domain events (and documentation).
  */
 @Disabled
+@TestPropertySource("foo=The Root")
 // tag::domain-events[]
 public class DomainEventsTest {
 
@@ -57,6 +59,9 @@ void customQueryShouldWork() {
 
 		optionalAggregate = aRepository.findByCustomQueryWithSpEL("The ", "Root");
 		assertThat(optionalAggregate).isPresent();
+
+		optionalAggregate = aRepository.findByCustomQueryWithPropertyPlaceholder();
+		assertThat(optionalAggregate).isPresent();
 	}
 
 	// tag::domain-events[]