@7polo/kityminder-core
Version:
KityMinder Core Implement
214 lines (190 loc) • 8.89 kB
JavaScript
define(function(require, exports, module) {
/*!
** Thenable -- Embeddable Minimum Strictly-Compliant Promises/A+ 1.1.1 Thenable
** Copyright (c) 2013-2014 Ralf S. Engelschall <http://engelschall.com>
** Licensed under The MIT License <http://opensource.org/licenses/MIT>
** Source-Code distributed on <http://github.com/rse/thenable>
*/
/* promise states [Promises/A+ 2.1] */
var STATE_PENDING = 0; /* [Promises/A+ 2.1.1] */
var STATE_FULFILLED = 1; /* [Promises/A+ 2.1.2] */
var STATE_REJECTED = 2; /* [Promises/A+ 2.1.3] */
/* promise object constructor */
var Promise = function(executor) {
/* optionally support non-constructor/plain-function call */
if (!(this instanceof Promise))
return new Promise(executor);
/* initialize object */
this.id = 'Thenable/1.0.7';
this.state = STATE_PENDING; /* initial state */
this.fulfillValue = undefined; /* initial value */ /* [Promises/A+ 1.3, 2.1.2.2] */
this.rejectReason = undefined; /* initial reason */ /* [Promises/A+ 1.5, 2.1.3.2] */
this.onFulfilled = []; /* initial handlers */
this.onRejected = []; /* initial handlers */
/* support optional executor function */
if (typeof executor === 'function')
executor.call(this, this.fulfill.bind(this), this.reject.bind(this));
};
/* Promise API methods */
Promise.prototype = {
/* promise resolving methods */
fulfill: function(value) { return deliver(this, STATE_FULFILLED, 'fulfillValue', value); },
reject: function(value) { return deliver(this, STATE_REJECTED, 'rejectReason', value); },
/* 'The then Method' [Promises/A+ 1.1, 1.2, 2.2] */
then: function(onFulfilled, onRejected) {
var curr = this;
var next = new Promise(); /* [Promises/A+ 2.2.7] */
curr.onFulfilled.push(
resolver(onFulfilled, next, 'fulfill')); /* [Promises/A+ 2.2.2/2.2.6] */
curr.onRejected.push(
resolver(onRejected, next, 'reject')); /* [Promises/A+ 2.2.3/2.2.6] */
execute(curr);
return next; /* [Promises/A+ 2.2.7, 3.3] */
}
};
Promise.all = function (arr) {
return new Promise(function(resolve, reject) {
var len = arr.length,
i = 0,
res = 0,
results = [];
if (len === 0) {
resolve(results);
}
while (i < len) {
arr[i].then(
function (result) {
results.push(result);
if (++res === len) {
resolve(results);
}
},
function (val) {
reject(val);
}
);
i++;
}
});
};
/* deliver an action */
var deliver = function(curr, state, name, value) {
if (curr.state === STATE_PENDING) {
curr.state = state; /* [Promises/A+ 2.1.2.1, 2.1.3.1] */
curr[name] = value; /* [Promises/A+ 2.1.2.2, 2.1.3.2] */
execute(curr);
}
return curr;
};
/* execute all handlers */
var execute = function(curr) {
if (curr.state === STATE_FULFILLED)
execute_handlers(curr, 'onFulfilled', curr.fulfillValue);
else if (curr.state === STATE_REJECTED)
execute_handlers(curr, 'onRejected', curr.rejectReason);
};
/* execute particular set of handlers */
var execute_handlers = function(curr, name, value) {
/* global process: true */
/* global setImmediate: true */
/* global setTimeout: true */
/* short-circuit processing */
if (curr[name].length === 0)
return;
/* iterate over all handlers, exactly once */
var handlers = curr[name];
curr[name] = []; /* [Promises/A+ 2.2.2.3, 2.2.3.3] */
var func = function() {
for (var i = 0; i < handlers.length; i++)
handlers[i](value); /* [Promises/A+ 2.2.5] */
};
/* execute procedure asynchronously */ /* [Promises/A+ 2.2.4, 3.1] */
if (typeof process === 'object' && typeof process.nextTick === 'function')
process.nextTick(func);
else if (typeof setImmediate === 'function')
setImmediate(func);
else
setTimeout(func, 0);
};
/* generate a resolver function */
var resolver = function(cb, next, method) {
return function(value) {
if (typeof cb !== 'function') /* [Promises/A+ 2.2.1, 2.2.7.3, 2.2.7.4] */
next[method].call(next, value); /* [Promises/A+ 2.2.7.3, 2.2.7.4] */
else {
var result;
try {
if (value instanceof Promise) {
result = value.then(cb);
}
else result = cb(value);
} /* [Promises/A+ 2.2.2.1, 2.2.3.1, 2.2.5, 3.2] */
catch (e) {
next.reject(e); /* [Promises/A+ 2.2.7.2] */
return;
}
resolve(next, result); /* [Promises/A+ 2.2.7.1] */
}
};
};
/* 'Promise Resolution Procedure' */ /* [Promises/A+ 2.3] */
var resolve = function(promise, x) {
/* sanity check arguments */ /* [Promises/A+ 2.3.1] */
if (promise === x) {
promise.reject(new TypeError('cannot resolve promise with itself'));
return;
}
/* surgically check for a 'then' method
(mainly to just call the 'getter' of 'then' only once) */
var then;
if ((typeof x === 'object' && x !== null) || typeof x === 'function') {
try { then = x.then; } /* [Promises/A+ 2.3.3.1, 3.5] */
catch (e) {
promise.reject(e); /* [Promises/A+ 2.3.3.2] */
return;
}
}
/* handle own Thenables [Promises/A+ 2.3.2]
and similar 'thenables' [Promises/A+ 2.3.3] */
if (typeof then === 'function') {
var resolved = false;
try {
/* call retrieved 'then' method */ /* [Promises/A+ 2.3.3.3] */
then.call(x,
/* resolvePromise */ /* [Promises/A+ 2.3.3.3.1] */
function(y) {
if (resolved) return; resolved = true; /* [Promises/A+ 2.3.3.3.3] */
if (y === x) /* [Promises/A+ 3.6] */
promise.reject(new TypeError('circular thenable chain'));
else
resolve(promise, y);
},
/* rejectPromise */ /* [Promises/A+ 2.3.3.3.2] */
function(r) {
if (resolved) return; resolved = true; /* [Promises/A+ 2.3.3.3.3] */
promise.reject(r);
}
);
}
catch (e) {
if (!resolved) /* [Promises/A+ 2.3.3.3.3] */
promise.reject(e); /* [Promises/A+ 2.3.3.3.4] */
}
return;
}
/* handle other values */
promise.fulfill(x); /* [Promises/A+ 2.3.4, 2.3.3.4] */
};
Promise.resolve = function(value) {
return new Promise(function(resolve) {
resolve(value);
});
};
Promise.reject = function(reason) {
return new Promise(function(resolve, reject) {
reject(reason);
});
};
/* export API */
module.exports = Promise;
});