ern-api-gen

This package is part of Electrode Native.

The Electrode Native API Generator creates new API projects based on a Swagger schema.

The generated code uses react-native-electrode-bridge to facilitate bi-directional message exchange between native code (Android/iOS) and JavaScript (React Native).

Usage

See the documentation and CLI help for more information:

ern create-api --help

Details

ern-api-gen is based on code from the Swagger project, mainly version 2.X of Swagger Codegen.

Stock (Swagger) Code Generators

The three primary code generators adapted from Swagger are:

• AndroidClientCodegen
• JavascriptClientCodegen
• SwiftCodegen

In line with the main Swagger project, all three classes extend the base class DefaultCodegen.

Custom (ERN) Code Generators

For the purposes of ern-api-gen there are three custom implementations of API code generators for native code (Java/Swift) and JavaScript:

Codegen | Base Class | Template Folder --- | --- | --- ErnAndroidApiCodegen | AndroidClientCodegen | resources/android/libraries/ern/ ErnES6ApiCodegen | ES6Codegen | resources/es6/libraries/ern/ ErnSwiftCodegen | SwiftCodegen | resources/swift/libraries/ern/

Note that ErnES6ApiCodegen extends ES6Codegen, not JavascriptClientCodegen (see next section for details).

ES6 Generator

The base class of ErnES6ApiCodegen is the ES6Codegen class which extends JavascriptClientCodegen. ES6Codegen uses a different template directory but otherwise does not change functionality much compared to its base class. It's important to understand that Swagger does not have a ES6Codegen and instead uses conditionals in JavascriptClientCodegen to generate ES6. The ES6 template folder of Swagger differs significantly from the one in ern-api-gen. This is likely due to the fact that ES6 generation was not yet available in Swagger at the time the initial code was converted for ern-api-gen.

History

Below is a brief summary of the significant events in this module. The information was mainly obtained from Git logs and by comparing select snapshots to historic state of swagger-codegen.

Initial version

The very first version of the content in this folder can be traced back to the addition of the ern-message-gen folder in 36637761 on Apr 4, 2017.

When the code was first added to the repository it had not only gone through a Java to JavaScript conversion, but also contained other changes and additions. Some changes in the resource files (e.g. triple curly braces) may have been a necessity due to subtle differences of the Mustache template engine in Java, and the mustache JavaScript package used by ern-api-gen. For these two reasons is it very difficult (or impossible) to determine the exact state of the Swagger project that was used as the actual "source".

The most accurate approximations point to somewhere between v2.2.1 and v2.2.2, with most code being closer to v2.2.1, while a few files more closely resemble v2.2.2. There are more than 900 commits between the two tags.

Rename

ern-message-gen was renamed to ern-api-gen on Aug 9, 2017 (0f9e0e34). This fully replaced the previous hull-based generator from the initial commit.

TypeScript conversion

A major update (mainly formatting) was done in 8fea575a when the rest of the Electrode Native code base was converted to TypeScript on Apr 28, 2018.

In May 2019, the JavaScript sources in ern-api-gen were converted to TypeScript: 92b69b9b (as well as 6d8f166a, 2e7d2327).