ravel
Version:
Ravel Rapid Application Development Framework
60 lines (57 loc) • 3.6 kB
JavaScript
;
const ApplicationError = require('../../util/application_error');
const Metadata = require('../../util/meta');
/**
* Dependency injection decorator for Ravel `Modules`,
* `Resources` and `Routes`.
* Based on Aurelia @inject decorator, but without the
* es6 module format. Since eliminating relative require()s
* has always been one of the core goals of the Ravel
* framework, this decorator takes strings instead of
* actual references to require()d modules. This string
* is either the name of the module to require, or the
* registered name of a client Ravel Module. Ravel Modules
* override npm modules.
*
* This decorator simply annotates the class with modules which
* should be injected when Ravel initializes. See `util/injector`
* for the actual DI implementation.
*
* @param {String...} rest - The names of `Module`s or npm modules to inject.
* @example
* // @inject works the same way on Modules, Resources and Routes
* const inject = require('ravel').inject;
* const Module = require('ravel').Module;
*
* // @inject('path', 'fs', 'custom-module')
* class MyModule extends Module {
* constructor (path, fs, custom) {
* super();
* this.path = path;
* this.fs = fs;
* this.custom = custom;
* }
*
* aMethod() {
* // can access this.fs, this.path or this.custom
* }
* }
*/
const inject = function (...rest) {
return function (target) {
if (rest.length === 0) {
throw new ApplicationError.NotFound(`Empty @inject supplied on ${typeof target}`);
}
for (const elem of rest) {
if (typeof elem !== 'string') {
throw new ApplicationError.IllegalValue('Values supplied to @inject decorator must be strings.');
}
}
Metadata.putClassMeta(target.prototype, '@inject', 'dependencies',
rest.concat(Metadata.getClassMetaValue(target.prototype, '@inject', 'dependencies', [])));
};
};
/*!
* Populates a class with a static reference to the // @inject decorator
*/
module.exports = inject;