b38dea0597
Share Gaia assets and adapters, keep private profiles and development documents local, and update both public READMEs.
66 lines
1.9 KiB
JavaScript
Executable file
66 lines
1.9 KiB
JavaScript
Executable file
(function(exports) {
|
|
'use strict';
|
|
|
|
/**
|
|
* The PipedPromise is a 'trait' or 'mixin' for other module to mix it in.
|
|
* Under certain situation, when we implement method that returns a Promise
|
|
* to callee, we don't want the method to be reentrant and instantiate another
|
|
* promise. We would like the request to be 'piped' in the same promise.
|
|
* This is the case where PipedPromise comes to our resque.
|
|
*
|
|
* @example
|
|
* SomeModule.prototype = {
|
|
* ...
|
|
* willReturnPromise: function willReturnPromise() {
|
|
* return this._getPipedPromise('willReturnPromise',
|
|
* function(resolve, reject) {
|
|
* ...
|
|
* });
|
|
* },
|
|
* ...
|
|
* };
|
|
* addMixin(SomeModule, PipedPromise);
|
|
*
|
|
*/
|
|
var PipedPromise = {
|
|
_removePipedPromise: function pp_removePipedPromise(key) {
|
|
if (!this._piped_promises) {
|
|
this._piped_promises = {};
|
|
}
|
|
|
|
this._piped_promises[key] = undefined;
|
|
},
|
|
|
|
/**
|
|
* Get Promise object of specific key. It will generate a new Promise
|
|
* if Promise of the key is not existed yet.
|
|
*
|
|
* @param {String} key - key of the Promise
|
|
* @param {Function} executor - the executor once the Promise resolved
|
|
* or rejected
|
|
* @returns {Promise} - A Promise
|
|
*
|
|
*/
|
|
_getPipedPromise: function pp_getOrCreatePromise(key, executor) {
|
|
if (!this._piped_promises) {
|
|
this._piped_promises = {};
|
|
}
|
|
|
|
var that = this;
|
|
var promise = this._piped_promises[key];
|
|
if (!promise) {
|
|
promise = new Promise(executor);
|
|
Promise.all([promise]).then(function onFulfill() {
|
|
that._removePipedPromise(key);
|
|
}, function onReject() {
|
|
that._removePipedPromise(key);
|
|
});
|
|
that._piped_promises[key] = promise;
|
|
}
|
|
return promise;
|
|
}
|
|
};
|
|
|
|
exports.PipedPromise = PipedPromise;
|
|
|
|
}(window));
|