My Experiences Generating API Server or Client Code Using Swagger
26 Jan 2015
When you start talking about generating server or client side code for APIs, using machine readable API definition formats like Swagger or API Blueprint, many technologists feel compelled to let you know, that at some point you will hit a wall. There is only so far you can go, when using your API definition as guide for generating server-side or clienit-side code, but in my experience you can definitely save some significant time an energy, by auto-generating code using Swagger definitions.
I just finished re-designing 15 APIs that support the core of API Evangelist, and to support the work I wrote four separate code generation tools:
- PHP Server - Generating a Slim PHP framework for my API, based upon Swagger definition.
- PHP Client - Assemble a custom PHP client of my design, using Swagger definition as guide.
- MySQL Database - Generate a MySQL script based upon the data models available in a Swagger definition.
Using Swagger, I can get myself 90-100% of the way for most of the common portions of the APIs I design. When writing a simple CRUD API like notes, or for links, I can auto-generate the PHP server, and a JS client, and underlying MySQL table structure, which in the end, runs perfectly with no changes.
Once I needed more custom functionality, and have more unique API calls to make, I then have to get my hands dirty, and begin manually working in the code. However auto-generation of code sure gets me a long way down the road, saving me time doing the really mundane, heavy lifting in creating the skeleton code structures I need to get up an running with any new API.
I’m also exploring using APIs.json, complete with Swagger references, and Docker image references to further bridge this gap. In my opinion, a Swagger definition for any API, can act as a fingerprint for which interfaces a docker image supports. I will write about this more in the future, as I produce better examples, but I'm finding that using APIs.json to bind a Swagger definition, with one or many Docker images, opens up a whole new view of how you can automate API deployment, management, and integration.