Merge pull request #163 from guy120494/custom-paging

Custom paging

Author: yarinvak

README.md

@@ -307,3 +307,17 @@ NOTE: because `PropertyDataFetcher` and `FieldDataFetcher` can't handle connecti
 By default, GraphQLAnnotations will use the `graphql.relay.Relay` class to create the Relay specific schema types (Mutations, Connections, Edges, PageInfo, ...).
 It is possible to set a custom implementation of the Relay class with `GraphQLAnnotations.setRelay` method. The class should inherit from `graphql.relay.Relay` and 
 can redefine methods that create Relay types.
+
+It is also possible to specify for every connection which relay do you want to use, by giving a value to the annotation: 
+`@GraphQLConnection(connectionType = customRelay.class)`. If you do that, please also give values to `connectionFetcher`
+and `validator`.
+
+There is also a support for simple paging, without "Nodes" and "Edges". To use it, annotate you connection like that:
+`@GraphQLConnection(connectionFetcher = SimplePaginatedDataConnectionFetcher.class, connectionType = SimpleRelay.class, validator = SimplePaginatedDataConnectionTypeValidator.class)`
+and the return type must be of type `SimplePaginatedData`.
+It has 2 methods:
+1. `getTotalCount` - how many elements are there in total
+2. `getData` - get the data
+
+For you convenience, there are two classes that you can use: `AbstractSimplePaginatedData` and `SimplePaginatedDataImpl`
+For examples, look at the tests

build.gradle

@@ -11,9 +11,9 @@ buildscript {
     }
 }
 plugins {
-    id "com.github.hierynomus.license" version "0.12.1"
     id "com.jfrog.bintray" version "1.7"
     id 'net.researchgate.release' version '2.3.4'
+    id "com.github.hierynomus.license" version "0.14.0"
 }
 
 apply plugin: 'java'

src/main/java/graphql/annotations/connection/FakeRelay.java

@@ -0,0 +1,23 @@
+/**
+ * Copyright 2016 Yurii Rashkovskii
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ */
+package graphql.annotations.connection;
+
+import graphql.relay.Relay;
+
+/**
+ * This class is just for the library to know whether to use the relay in the container or not
+ */
+public final class FakeRelay extends Relay {
+}

src/main/java/graphql/annotations/connection/GraphQLConnection.java

@@ -15,6 +15,8 @@
 package graphql.annotations.connection;
 
 
+import graphql.relay.Relay;
+
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -27,7 +29,7 @@
  *
  * At the moment, the only allowed type for such field is <code>List&lt;?&gt;</code>
  */
-@Target({ElementType.FIELD, ElementType.METHOD})
+@Target({ElementType.FIELD, ElementType.METHOD, ElementType.TYPE})
 @Retention(RetentionPolicy.RUNTIME)
 public @interface GraphQLConnection {
     /**
@@ -37,7 +39,7 @@
      * your own connection validator
      * @return a connection class
      */
-    Class<? extends ConnectionFetcher> connection() default PaginatedDataConnectionFetcher.class;
+    Class<? extends ConnectionFetcher> connectionFetcher() default PaginatedDataConnectionFetcher.class;
 
     /**
      * By default, wrapped type's name is used for naming TypeConnection, but can be overridden
@@ -59,4 +61,12 @@
      * @return if async fetching to be used.
      */
     boolean async() default false;
+
+    /**
+     * By default, the relay connection that the container has is used. If you want to change the way connection works
+     * (For example, you don't want edges and nodes), override the {@link Relay} class and specify it.
+     *
+     * @return a class that represents the connection type
+     */
+    Class<? extends Relay> connectionType() default FakeRelay.class;
 }

src/main/java/graphql/annotations/connection/SimplePaginatedData.java renamed to src/main/java/graphql/annotations/connection/NaivePaginatedData.java

@@ -19,15 +19,15 @@
 
 import static java.util.Base64.getEncoder;
 
-public class SimplePaginatedData<T> extends AbstractPaginatedData<T> {
+public class NaivePaginatedData<T> extends AbstractPaginatedData<T> {
     private static final String DUMMY_CURSOR_PREFIX = "simple-cursor";
     private final String prefix;
 
-    public SimplePaginatedData(boolean hasPreviousPage, boolean hasNextPage, Iterable<T> data) {
+    public NaivePaginatedData(boolean hasPreviousPage, boolean hasNextPage, Iterable<T> data) {
         this(hasPreviousPage, hasNextPage, data, DUMMY_CURSOR_PREFIX);
     }
 
-    public SimplePaginatedData(boolean hasPreviousPage, boolean hasNextPage, Iterable<T> data, String prefix) {
+    public NaivePaginatedData(boolean hasPreviousPage, boolean hasNextPage, Iterable<T> data, String prefix) {
         super(hasPreviousPage, hasNextPage, data);
         this.prefix = prefix;
     }

src/main/java/graphql/annotations/connection/PaginatedDataConnectionTypeValidator.java

@@ -16,6 +16,7 @@
 
 
 import graphql.annotations.annotationTypes.GraphQLDataFetcher;
+import graphql.annotations.connection.exceptions.GraphQLConnectionException;
 
 import java.lang.reflect.AccessibleObject;
 import java.lang.reflect.Field;

src/main/java/graphql/annotations/connection/GraphQLConnectionException.java renamed to src/main/java/graphql/annotations/connection/exceptions/GraphQLConnectionException.java

@@ -12,11 +12,11 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  */
-package graphql.annotations.connection;
+package graphql.annotations.connection.exceptions;
 
-class GraphQLConnectionException extends RuntimeException {
+public class GraphQLConnectionException extends RuntimeException {
 
-    GraphQLConnectionException(String error) {
+    public GraphQLConnectionException(String error) {
         super(error);
     }
 }

src/main/java/graphql/annotations/connection/simple/AbstractSimplePaginatedData.java

@@ -0,0 +1,39 @@
+/**
+ * Copyright 2016 Yurii Rashkovskii
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ */
+package graphql.annotations.connection.simple;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+public abstract class AbstractSimplePaginatedData<T> implements SimplePaginatedData<T> {
+    private Iterable<T> data;
+
+    public AbstractSimplePaginatedData(Iterable<T> data) {
+        this.data = data;
+    }
+
+    @Override
+    public Iterator<T> iterator() {
+        return data.iterator();
+    }
+
+    @Override
+    public List<T> getData() {
+        List<T> dataList = new ArrayList<>();
+        data.forEach(dataList::add);
+        return dataList;
+    }
+}

src/main/java/graphql/annotations/connection/simple/SimpleConnection.java

@@ -0,0 +1,55 @@
+/**
+ * Copyright 2016 Yurii Rashkovskii
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ */
+package graphql.annotations.connection.simple;
+
+
+import graphql.relay.Connection;
+import graphql.relay.Edge;
+import graphql.relay.PageInfo;
+
+import java.util.List;
+
+/**
+ * This is a more intuitive implementation for paging. You send back only the data that is requested,
+ * along with "overall" - the amount of all the entities
+ *
+ * @param <T> The type of the entities
+ */
+public interface SimpleConnection<T> extends Connection<T> {
+
+    /**
+     * Get the list of the entities
+     *
+     * @return List of entities
+     */
+    List<T> getData();
+
+    /**
+     * The amount of entities
+     *
+     * @return The amount of entities
+     */
+    long getTotalCount();
+
+    @Override
+    default List<Edge<T>> getEdges() {
+        throw new UnsupportedOperationException("Simple paging doesn't have edges");
+    }
+
+    @Override
+    default PageInfo getPageInfo() {
+        throw new UnsupportedOperationException("Simple paging doesn't have page info");
+    }
+}

src/main/java/graphql/annotations/connection/simple/SimpleConnectionDataFetcher.java

@@ -0,0 +1,51 @@
+/**
+ * Copyright 2016 Yurii Rashkovskii
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ */
+package graphql.annotations.connection.simple;
+
+import graphql.relay.Connection;
+import graphql.schema.DataFetcher;
+import graphql.schema.DataFetchingEnvironment;
+
+import java.lang.reflect.Constructor;
+import java.util.Arrays;
+import java.util.Optional;
+
+import static graphql.annotations.processor.util.ReflectionKit.constructNewInstance;
+
+public class SimpleConnectionDataFetcher<T> implements SimpleConnectionFetcher<T> {
+    private final DataFetcher<?> actualDataFetcher;
+    private final Constructor<SimpleConnectionFetcher<T>> constructor;
+
+    @SuppressWarnings("unchecked")
+    public SimpleConnectionDataFetcher(Class<? extends SimpleConnectionFetcher<T>> connection, DataFetcher<?> actualDataFetcher) {
+        this.actualDataFetcher = actualDataFetcher;
+        Optional<Constructor<SimpleConnectionFetcher<T>>> constructor =
+                Arrays.stream(connection.getConstructors()).
+                        filter(c -> c.getParameterCount() == 1).
+                        map(c -> (Constructor<SimpleConnectionFetcher<T>>) c).
+                        findFirst();
+        if (constructor.isPresent()) {
+            this.constructor = constructor.get();
+        } else {
+            throw new IllegalArgumentException(connection.getSimpleName() + " doesn't have a single argument constructor");
+        }
+    }
+
+    @Override
+    public Connection<T> get(DataFetchingEnvironment environment) {
+        SimpleConnectionFetcher<T> conn = constructNewInstance(constructor, actualDataFetcher);
+        return conn.get(environment);
+    }
+}