wallet-core/node_modules/use/index.js
2017-08-14 05:02:09 +02:00

122 lines
2.6 KiB
JavaScript

/*!
* use <https://github.com/jonschlinkert/use>
*
* Copyright (c) 2015, 2017, Jon Schlinkert.
* Released under the MIT License.
*/
'use strict';
var utils = require('./utils');
module.exports = function base(app, opts) {
if (!utils.isObject(app) && typeof app !== 'function') {
throw new TypeError('use: expect `app` be an object or function');
}
if (!utils.isObject(opts)) {
opts = {};
}
var prop = utils.isString(opts.prop) ? opts.prop : 'fns';
if (!Array.isArray(app[prop])) {
utils.define(app, prop, []);
}
/**
* Define a plugin function to be passed to use. The only
* parameter exposed to the plugin is `app`, the object or function.
* passed to `use(app)`. `app` is also exposed as `this` in plugins.
*
* Additionally, **if a plugin returns a function, the function will
* be pushed onto the `fns` array**, allowing the plugin to be
* called at a later point by the `run` method.
*
* ```js
* var use = require('use');
*
* // define a plugin
* function foo(app) {
* // do stuff
* }
*
* var app = function(){};
* use(app);
*
* // register plugins
* app.use(foo);
* app.use(bar);
* app.use(baz);
* ```
* @name .use
* @param {Function} `fn` plugin function to call
* @api public
*/
utils.define(app, 'use', use);
/**
* Run all plugins on `fns`. Any plugin that returns a function
* when called by `use` is pushed onto the `fns` array.
*
* ```js
* var config = {};
* app.run(config);
* ```
* @name .run
* @param {Object} `value` Object to be modified by plugins.
* @return {Object} Returns the object passed to `run`
* @api public
*/
utils.define(app, 'run', function(val) {
if (!utils.isObject(val)) return;
decorate(val);
var self = this || app;
var fns = self[prop];
var len = fns.length;
var idx = -1;
while (++idx < len) {
val.use(fns[idx]);
}
return val;
});
/**
* Call plugin `fn`. If a function is returned push it into the
* `fns` array to be called by the `run` method.
*/
function use(fn, options) {
if (typeof fn !== 'function') {
throw new TypeError('.use expects `fn` be a function');
}
var self = this || app;
if (typeof opts.fn === 'function') {
opts.fn.call(self, self, options);
}
var plugin = fn.call(self, self);
if (typeof plugin === 'function') {
var fns = self[prop];
fns.push(plugin);
}
return self;
}
/**
* Ensure the `.use` method exists on `val`
*/
function decorate(val) {
if (!val.use || !val.run) {
base(val);
}
}
return app;
};