openapi-generator/samples/meta-codegen/lib

OpenAPI Generator for the myClientCodegen library

Overview

This is a boiler-plate project to generate your own client library with Swagger. Its goal is to get you started with the basic plumbing so you can put in your own logic. It won't work without your changes applied.

What's Swagger?

The goal of Swagger™ is to define a standard, language-agnostic interface to REST APIs which allows both humans and computers to discover and understand the capabilities of the service without access to source code, documentation, or through network traffic inspection. When properly defined via Swagger, a consumer can understand and interact with the remote service with a minimal amount of implementation logic. Similar to what interfaces have done for lower-level programming, Swagger removes the guesswork in calling the service.

Check out OpenAPI-Spec for additional information about the Swagger project, including additional libraries with support for other languages and more.

How do I use this?

At this point, you've likely generated a client setup. It will include something along these lines:

.
|- README.md    // this file
|- pom.xml      // build script
|-- src
|--- main
|---- java
|----- com.my.company.codegen.MyclientcodegenGenerator.java // generator file
|---- resources
|----- myClientCodegen // template files
|----- META-INF
|------ services
|------- org.openapitools.codegen.CodegenConfig

You will need to make changes in at least the following:

MyclientcodegenGenerator.java

Templates in this folder:

src/main/resources/myClientCodegen

Once modified, you can run this:

mvn package

In your generator project. A single jar file will be produced in target. You can now use that with codegen:

java -cp /path/to/openapi-generator-cli.jar:/path/to/your.jar org.openapitools.codegen.Codegen -g myClientCodegen -i /path/to/openapi.yaml -o ./test

Now your templates are available to the client generator and you can write output values

But how do I modify this?

The MyclientcodegenGenerator.java has comments in it--lots of comments. There is no good substitute for reading the code more, though. See how the MyclientcodegenGenerator implements CodegenConfig. That class has the signature of all values that can be overridden.

For the templates themselves, you have a number of values available to you for generation. You can execute the java command from above while passing different debug flags to show the object you have available during client generation:

# The following additional debug options are available for all codegen targets:
# -DdebugSwagger prints the OpenAPI Specification as interpreted by the codegen
# -DdebugModels prints models passed to the template engine
# -DdebugOperations prints operations passed to the template engine
# -DdebugSupportingFiles prints additional data passed to the template engine

java -DdebugOperations -cp /path/to/openapi-generator-cli.jar:/path/to/your.jar org.openapitools.codegen.Codegen -g myClientCodegen -i /path/to/swagger.yaml -o ./test

Will, for example, output the debug info for operations. You can use this info in the api.mustache file.