/**
* The YUI module contains the components required for building the YUI seed file.
* This includes the script loading mechanism, a simple queue, and the core utilities for the library.
* @module yui
* @submodule yui-base
*/
(function() {
var L = Y.Lang,
DELIMITER = '__',
// FROZEN = {
// 'prototype': 1,
// '_yuid': 1
// },
/*
* IE will not enumerate native functions in a derived object even if the
* function was overridden. This is a workaround for specific functions
* we care about on the Object prototype.
* @property _iefix
* @for YUI
* @param {Function} r the object to receive the augmentation
* @param {Function} s the object that supplies the properties to augment
* @private
*/
_iefix = function(r, s) {
var fn = s.toString;
if (L.isFunction(fn) && fn != Object.prototype.toString) {
r.toString = fn;
}
};
/**
* Returns a new object containing all of the properties of
* all the supplied objects. The properties from later objects
* will overwrite those in earlier objects. Passing in a
* single object will create a shallow copy of it. For a deep
* copy, use clone.
* @method merge
* @for YUI
* @param arguments {Object*} the objects to merge
* @return {object} the new merged object
*/
Y.merge = function() {
var a = arguments, o = {}, i, l = a.length;
for (i=0; i<l; i=i+1) {
Y.mix(o, a[i], true);
}
return o;
};
/**
* Applies the supplier's properties to the receiver. By default
* all prototype and static propertes on the supplier are applied
* to the corresponding spot on the receiver. By default all
* properties are applied, and a property that is already on the
* reciever will not be overwritten. The default behavior can
* be modified by supplying the appropriate parameters.
*
* @TODO add constants for the modes
*
* @method mix
* @param {Function} r the object to receive the augmentation
* @param {Function} s the object that supplies the properties to augment
* @param ov {boolean} if true, properties already on the receiver
* will be overwritten if found on the supplier.
* @param wl {string[]} a whitelist. If supplied, only properties in
* this list will be applied to the receiver.
* @param {int} mode what should be copies, and to where
* default(0): object to object
* 1: prototype to prototype (old augment)
* 2: prototype to prototype and object props (new augment)
* 3: prototype to object
* 4: object to prototype
* @param merge {boolean} merge objects instead of overwriting/ignoring
* Used by Y.aggregate
* @return {object} the augmented object
*/
Y.mix = function(r, s, ov, wl, mode, merge) {
if (!s||!r) {
return r || Y;
}
if (mode) {
switch (mode) {
case 1: // proto to proto
return Y.mix(r.prototype, s.prototype, ov, wl, 0, merge);
case 2: // object to object and proto to proto
Y.mix(r.prototype, s.prototype, ov, wl, 0, merge);
break; // pass through
case 3: // proto to static
return Y.mix(r, s.prototype, ov, wl, 0, merge);
case 4: // static to proto
return Y.mix(r.prototype, s, ov, wl, 0, merge);
default: // object to object is what happens below
}
}
// Maybe don't even need this wl && wl.length check anymore??
var arr = merge && L.isArray(r), i, l, p;
if (wl && wl.length) {
for (i = 0, l = wl.length; i < l; ++i) {
p = wl[i];
if (p in s) {
if (merge && L.isObject(r[p], true)) {
Y.mix(r[p], s[p]);
} else if (!arr && (ov || !(p in r))) {
r[p] = s[p];
} else if (arr) {
r.push(s[p]);
}
}
}
} else {
for (i in s) {
// if (s.hasOwnProperty(i) && !(i in FROZEN)) {
// check white list if it was supplied
// if the receiver has this property, it is an object,
// and merge is specified, merge the two objects.
if (merge && L.isObject(r[i], true)) {
Y.mix(r[i], s[i]); // recursive
// otherwise apply the property only if overwrite
// is specified or the receiver doesn't have one.
} else if (!arr && (ov || !(i in r))) {
r[i] = s[i];
// if merge is specified and the receiver is an array,
// append the array item
} else if (arr) {
r.push(s[i]);
}
// }
}
if (Y.UA.ie) {
_iefix(r, s);
}
}
return r;
};
/**
* Returns a wrapper for a function which caches the
* return value of that function, keyed off of the combined
* argument values.
* @function cached
* @param source {function} the function to memoize
* @param cache an optional cache seed
* @param refetch if supplied, this value is tested against the cached
* value. If the values are equal, the wrapped function is executed again.
* @return {Function} the wrapped function
*/
Y.cached = function(source, cache, refetch){
cache = cache || {};
return function(arg1, arg2) {
var k = (arg2) ? Array.prototype.join.call(arguments, DELIMITER) : arg1,
v = cache[k];
if (!(k in cache) || (refetch && cache[k] == refetch)) {
cache[k] = source.apply(source, arguments);
}
return cache[k];
};
};
})();