neo4j-graphql · jexp · Mar 25, 2021 · Mar 4, 2021
diff --git a/core/src/main/kotlin/org/neo4j/graphql/SchemaBuilder.kt b/core/src/main/kotlin/org/neo4j/graphql/SchemaBuilder.kt
@@ -15,6 +15,9 @@ import org.neo4j.graphql.handler.relation.CreateRelationHandler
 import org.neo4j.graphql.handler.relation.CreateRelationTypeHandler
 import org.neo4j.graphql.handler.relation.DeleteRelationHandler
 
+/**
+ * Contains factory methods to generate an augmented graphql schema
+ */
 object SchemaBuilder {
 
     /**
@@ -31,6 +34,12 @@ object SchemaBuilder {
         return buildSchema(typeDefinitionRegistry, config, dataFetchingInterceptor)
     }
 
+    /**
+     * @param typeDefinitionRegistry a registry containing all the types, that should be augmented
+     * @param config defines how the schema should get augmented
+     * @param dataFetchingInterceptor since this library registers dataFetcher for its augmented methods, these data
+     * fetchers may be called by other resolver. This interceptor will let you convert a cypher query into real data.
+     */
     @JvmStatic
     @JvmOverloads
     fun buildSchema(typeDefinitionRegistry: TypeDefinitionRegistry, config: SchemaConfig = SchemaConfig(), dataFetchingInterceptor: DataFetchingInterceptor? = null): GraphQLSchema {

diff --git a/core/src/main/kotlin/org/neo4j/graphql/handler/BaseDataFetcher.kt b/core/src/main/kotlin/org/neo4j/graphql/handler/BaseDataFetcher.kt
@@ -11,6 +11,9 @@ import org.neo4j.graphql.Cypher
 import org.neo4j.graphql.aliasOrName
 import org.neo4j.graphql.handler.projection.ProjectionBase
 
+/**
+ * The is a base class for the implementation of graphql data fetcher used in this project
+ */
 abstract class BaseDataFetcher(val fieldDefinition: GraphQLFieldDefinition) : ProjectionBase(), DataFetcher<Cypher> {
 
     override fun get(env: DataFetchingEnvironment?): Cypher {

diff --git a/core/src/main/kotlin/org/neo4j/graphql/handler/BaseDataFetcherForContainer.kt b/core/src/main/kotlin/org/neo4j/graphql/handler/BaseDataFetcherForContainer.kt
@@ -9,6 +9,9 @@ import org.neo4j.cypherdsl.core.*
 import org.neo4j.cypherdsl.core.Cypher.*
 import org.neo4j.graphql.*
 
+/**
+ * This is a base class for all Node or Relation related data fetcher.
+ */
 abstract class BaseDataFetcherForContainer(
         val type: GraphQLFieldsContainer,
         fieldDefinition: GraphQLFieldDefinition

diff --git a/core/src/main/kotlin/org/neo4j/graphql/handler/CreateTypeHandler.kt b/core/src/main/kotlin/org/neo4j/graphql/handler/CreateTypeHandler.kt
@@ -6,6 +6,10 @@ import org.neo4j.cypherdsl.core.Statement
 import org.neo4j.cypherdsl.core.StatementBuilder
 import org.neo4j.graphql.*
 
+/**
+ * This class handles all the logic related to the creation of nodes.
+ * This includes the augmentation of the create&lt;Node&gt;-mutator and the related cypher generation
+ */
 class CreateTypeHandler private constructor(
         type: GraphQLFieldsContainer,
         fieldDefinition: GraphQLFieldDefinition

diff --git a/core/src/main/kotlin/org/neo4j/graphql/handler/CypherDirectiveHandler.kt b/core/src/main/kotlin/org/neo4j/graphql/handler/CypherDirectiveHandler.kt
@@ -9,6 +9,9 @@ import org.neo4j.cypherdsl.core.Functions
 import org.neo4j.cypherdsl.core.Statement
 import org.neo4j.graphql.*
 
+/**
+ * This class handles all logic related to custom Cypher queries declared by fields with a @cypher directive
+ */
 class CypherDirectiveHandler(
         private val type: GraphQLFieldsContainer?,
         private val isQuery: Boolean,

diff --git a/core/src/main/kotlin/org/neo4j/graphql/handler/DeleteHandler.kt b/core/src/main/kotlin/org/neo4j/graphql/handler/DeleteHandler.kt
@@ -8,6 +8,10 @@ import org.neo4j.cypherdsl.core.Statement
 import org.neo4j.cypherdsl.core.StatementBuilder.OngoingUpdate
 import org.neo4j.graphql.*
 
+/**
+ * This class handles all the logic related to the deletion of nodes.
+ * This includes the augmentation of the delete&lt;Node&gt;-mutator and the related cypher generation
+ */
 class DeleteHandler private constructor(
         type: GraphQLFieldsContainer,
         private val idField: GraphQLFieldDefinition,

diff --git a/core/src/main/kotlin/org/neo4j/graphql/handler/MergeOrUpdateHandler.kt b/core/src/main/kotlin/org/neo4j/graphql/handler/MergeOrUpdateHandler.kt
@@ -11,6 +11,10 @@ import org.neo4j.cypherdsl.core.Statement
 import org.neo4j.cypherdsl.core.StatementBuilder.OngoingMatchAndUpdate
 import org.neo4j.graphql.*
 
+/**
+ * This class handles all the logic related to the updating of nodes.
+ * This includes the augmentation of the update&lt;Node&gt; and merge&lt;Node&gt;-mutator and the related cypher generation
+ */
 class MergeOrUpdateHandler private constructor(
         type: GraphQLFieldsContainer,
         private val merge: Boolean,

diff --git a/core/src/main/kotlin/org/neo4j/graphql/handler/QueryHandler.kt b/core/src/main/kotlin/org/neo4j/graphql/handler/QueryHandler.kt
@@ -8,6 +8,10 @@ import org.neo4j.cypherdsl.core.Statement
 import org.neo4j.graphql.*
 import org.neo4j.graphql.handler.filter.OptimizedFilterHandler
 
+/**
+ * This class handles all the logic related to the querying of nodes and relations.
+ * This includes the augmentation of the query-fields and the related cypher generation
+ */
 class QueryHandler private constructor(
         type: GraphQLFieldsContainer,
         fieldDefinition: GraphQLFieldDefinition)

diff --git a/core/src/main/kotlin/org/neo4j/graphql/handler/filter/OptimizedFilterHandler.kt b/core/src/main/kotlin/org/neo4j/graphql/handler/filter/OptimizedFilterHandler.kt
@@ -22,6 +22,14 @@ typealias WhereClauseFactory = (
 
 typealias ConditionBuilder = (ExposesWith) -> OrderableOngoingReadingAndWithWithoutWhere
 
+/**
+ * This its a specialized handler that uses an alternative approach for filtering. By using multiple MATCH clauses,
+ * this can facilitate the use of optimizations within the neo4j database, which can lead to significant performance
+ * improvements for large data sets.
+ *
+ * If this handler cannot generate an optimization for the passed filter, an [OptimizedQueryException] will be
+ * thrown, so the calling site can fall back to the non-optimized logic
+ */
 class OptimizedFilterHandler(val type: GraphQLFieldsContainer) : ProjectionBase() {
 
     fun generateFilterQuery(variable: String, field: Field, readingWithoutWhere: OngoingReadingWithoutWhere, rootNode: PropertyContainer): OngoingReading {

diff --git a/core/src/main/kotlin/org/neo4j/graphql/handler/projection/ProjectionBase.kt b/core/src/main/kotlin/org/neo4j/graphql/handler/projection/ProjectionBase.kt
@@ -15,7 +15,9 @@ import org.neo4j.graphql.parser.ParsedQuery
 import org.neo4j.graphql.parser.QueryParser.parseArguments
 import org.neo4j.graphql.parser.QueryParser.parseFilter
 
-
+/**
+ * This class contains the logic for projecting nodes and relations
+ */
 open class ProjectionBase {
     companion object {
         const val NATIVE_ID = "_id"

diff --git a/core/src/main/kotlin/org/neo4j/graphql/handler/relation/BaseRelationHandler.kt b/core/src/main/kotlin/org/neo4j/graphql/handler/relation/BaseRelationHandler.kt
@@ -8,6 +8,9 @@ import org.neo4j.cypherdsl.core.Node
 import org.neo4j.graphql.*
 import org.neo4j.graphql.handler.BaseDataFetcherForContainer
 
+/**
+ * This is a base class for all handler acting on relations / edges
+ */
 abstract class BaseRelationHandler(
         type: GraphQLFieldsContainer,
         val relation: RelationshipInfo,

diff --git a/core/src/main/kotlin/org/neo4j/graphql/handler/relation/CreateRelationHandler.kt b/core/src/main/kotlin/org/neo4j/graphql/handler/relation/CreateRelationHandler.kt
@@ -9,6 +9,10 @@ import org.neo4j.cypherdsl.core.Statement
 import org.neo4j.cypherdsl.core.StatementBuilder.OngoingUpdate
 import org.neo4j.graphql.*
 
+/**
+ * This class handles all the logic related to the creation of relations starting from an existing node.
+ * This includes the augmentation of the add&lt;Edge&gt;-mutator and the related cypher generation
+ */
 class CreateRelationHandler private constructor(
         type: GraphQLFieldsContainer,
         relation: RelationshipInfo,

diff --git a/core/src/main/kotlin/org/neo4j/graphql/handler/relation/CreateRelationTypeHandler.kt b/core/src/main/kotlin/org/neo4j/graphql/handler/relation/CreateRelationTypeHandler.kt
@@ -7,6 +7,10 @@ import org.neo4j.cypherdsl.core.Statement
 import org.neo4j.cypherdsl.core.StatementBuilder
 import org.neo4j.graphql.*
 
+/**
+ * This class handles all the logic related to the creation of relations.
+ * This includes the augmentation of the create&lt;Edge&gt;-mutator and the related cypher generation
+ */
 class CreateRelationTypeHandler private constructor(
         type: GraphQLFieldsContainer,
         relation: RelationshipInfo,

diff --git a/core/src/main/kotlin/org/neo4j/graphql/handler/relation/DeleteRelationHandler.kt b/core/src/main/kotlin/org/neo4j/graphql/handler/relation/DeleteRelationHandler.kt
@@ -9,6 +9,10 @@ import org.neo4j.cypherdsl.core.Statement
 import org.neo4j.cypherdsl.core.StatementBuilder
 import org.neo4j.graphql.*
 
+/**
+ * This class handles all the logic related to the deletion of relations starting from an existing node.
+ * This includes the augmentation of the delete&lt;Edge&gt;-mutator and the related cypher generation
+ */
 class DeleteRelationHandler private constructor(
         type: GraphQLFieldsContainer,
         relation: RelationshipInfo,

diff --git a/core/src/main/kotlin/org/neo4j/graphql/parser/QueryParser.kt b/core/src/main/kotlin/org/neo4j/graphql/parser/QueryParser.kt
@@ -11,6 +11,9 @@ import org.neo4j.graphql.handler.projection.ProjectionBase
 
 typealias CypherDSL = org.neo4j.cypherdsl.core.Cypher
 
+/**
+ * An internal representation of all the filtering passed to an graphql field
+ */
 class ParsedQuery(
         val fieldPredicates: List<FieldPredicate>,
         val relationPredicates: List<RelationPredicate>,
@@ -31,6 +34,9 @@ abstract class Predicate<T>(
         val normalizedName: String,
         val index: Int)
 
+/**
+ * Predicates on a nodes' or relations' property
+ */
 class FieldPredicate(
         op: FieldOperator,
         queryField: ObjectField,
@@ -50,6 +56,10 @@ class FieldPredicate(
 
 }
 
+/**
+ * Predicate for a relation
+ */
+
 class RelationPredicate(
         type: GraphQLFieldsContainer,
         op: RelationOperator,
@@ -77,7 +87,9 @@ class RelationPredicate(
 
 object QueryParser {
 
-
+    /**
+     * This parser takes an filter object an transform it to the internal [ParsedQuery]-representation
+     */
     fun parseFilter(objectValue: ObjectValue, type: GraphQLFieldsContainer): ParsedQuery {
         // Map of all queried fields
         // we remove all matching fields from this map, so we can ensure that only known fields got queried
@@ -98,6 +110,9 @@ object QueryParser {
         return createParsedQuery(queriedFields, type, null, or, and)
     }
 
+    /**
+     * This parser takes all non-filter arguments of a graphql-field an transform it to the internal [ParsedQuery]-representation
+     */
     fun parseArguments(arguments: List<Argument>, fieldDefinition: GraphQLFieldDefinition, type: GraphQLFieldsContainer): ParsedQuery {
         // TODO we should check if the argument is defined on the field definition and throw an error otherwise
         // Map of all queried fields