usage_customtemplates

• Customizing code templates
• templates param usage
• Template IDs
• Examples

Customizing code templates

Code generated by the Graphql Maven Plugin is generated applying a set of Velocity templates to the input GraphQL Schmea. Templates are located in the project at graphql-maven-plugin-logic/src/main/resources/templates

If for any reason you may need to customize the template to modify the generated code, this can be done by using the plugin parameter templates

templates param usage

Here there's an example of plugin configuration to use customized templates

<project ...>
...

<build>
	<plugins>
...
		<plugin>
			<groupId>com.graphql-java-generator</groupId>
			<artifactId>graphql-maven-plugin</artifactId>
			<version>${lastReleasedVersion}</version>

			<executions>
				<execution>
					<goals>
						<goal>graphql</goal>
					</goals>
				</execution>
			</executions>
			<configuration>
				<mode>client</mode>
				<templates>
					<QUERY_MUTATION>classpath/entry/to/customtemplate.java.vm</QUERY_MUTATION>
				</templates>
			</configuration>
			<dependencies>

				<!-- Dependency containing your templates-->
				<dependency>
					<groupId>...</groupId>
					<artifactId>...</artifactId>
					<version>...</version>
				</dependency>

			</dependencies>
		</plugin>
	</plugins>
</build>
...
</project>

The templates param is a map where the key is the ID of the template to customize and the value is a classpath entry to the resources containing the customized template.

Customize templates shall be provided in a dependency configured in the plugin.

Both client and server templates can be customized.

Template IDs

The available template IDs that can be configured for customization are:

| OBJECT | COMMON | templates/object_type.vm.java | | INTERFACE | COMMON | templates/interface_type.vm.java | | ENUM | COMMON | templates/enum_type.vm.java | | UNION | COMMON | templates/union_type.vm.java | | CUSTOM_SCALAR_REGISTRY_INITIALIZER | CLIENT | templates/client_CustomScalarRegistryInitializer.vm.java | | QUERY_MUTATION | CLIENT | templates/client_query_mutation_type.vm.java | | QUERY_TARGET_TYPE | CLIENT | templates/client_query_target_type.vm.java | | JACKSON_DESERIALIZER | CLIENT | templates/client_jackson_deserialize.vm.java | | SUBSCRIPTION | CLIENT | templates/client_subscription_type.vm.java | | DATA_FETCHER | SERVER | templates/server_GraphQLDataFetchers.vm.java | | BATCH_LOADER_DELEGATE_IMPL | SERVER | templates/server_BatchLoaderDelegateImpl.vm.java | | DATA_FETCHER_DELEGATE | SERVER | [templates/server_GraphQLDataFetchersDelegate.vm.java](http://github.com/graphql-java-generator/graphql-maven-plugin-project/tree/master/graphql-maven-plugin-logic/src/main/resources/templates/server_GraphQLDataFetchersDelegate.vm.java | | GRAPHQLUTIL | SERVER | templates/server_GraphQLUtil.vm.java | | SERVER | SERVER | templates/server_GraphQLServerMain.vm.java | | WEB_SOCKET_CONFIG | SERVER | templates/server_WebSocketConfig.vm.java | | WEB_SOCKET_HANDLER | SERVER | templates/server_WebSocketHandler.vm.java | | WIRING | SERVER | templates/server_GraphQLWiring.vm.java |

Examples

Available on the project there is an example of this behavior:

• graphql-maven-plugin-samples-customtemplates-resttemplate: contains an example of a template customization for QUERY_MUTATION_SUBSCRIPTION template. Code generated uses a Spring implementation of com.graphql_java_generator.client.QueryExecutor that uses RestTemplate as the client
• graphql-maven-plugin-samples-customtemplates-client: a Spring-based client generated with the previous customized template.