yui-array.js revision 401d3c02d890d39b7a48d94e0a9c1830f8aade42
(function() {
/**
* YUI core
* @module yui
*/
var L = Y.Lang, Native = Array.prototype,
/**
* Adds the following array utilities to the YUI instance
* @class YUI~array
*/
/**
* Y.Array(o) returns an array:
* - Arrays are return unmodified unless the start position is specified.
* - "Array-like" collections (@see Array.test) are converted to arrays
* - For everything else, a new array is created with the input as the sole item
* - The start position is used if the input is or is like an array to return
* a subset of the collection.
*
* @TODO this will not automatically convert elements that are also collections
* such as forms and selects. Passing true as the third param will
* force a conversion.
*
* @method Array
* @static
* @param o the item to arrayify
* @param i {int} if an array or array-like, this is the start index
* @param al {boolean} if true, it forces the array-like fork. This
* can be used to avoid multiple array.test calls.
* @return {Array} the resulting array
*/
A = function(o, startIdx, al) {
var t = (al) ? 2 : Y.Array.test(o), i, l, a;
// switch (t) {
// case 1:
// // return (startIdx) ? o.slice(startIdx) : o;
// case 2:
// return Native.slice.call(o, startIdx || 0);
// default:
// return [o];
// }
if (t) {
try {
return Native.slice.call(o, startIdx || 0);
// IE errors when trying to slice element collections
} catch(e) {
a=[];
for (i=0, l=o.length; i<l; i=i+1) {
a.push(o[i]);
}
return a;
}
} else {
return [o];
}
};
Y.Array = A;
/**
* Evaluates the input to determine if it is an array, array-like, or
* something else. This is used to handle the arguments collection
* available within functions, and HTMLElement collections
*
* @method Array.test
* @static
*
* @todo current implementation (intenionally) will not implicitly
* handle html elements that are array-like (forms, selects, etc).
*
* @return {int} a number indicating the results:
* 0: Not an array or an array-like collection
* 1: A real array.
* 2: array-like collection.
*/
A.test = function(o) {
var r = 0;
if (L.isObject(o)) {
if (L.isArray(o)) {
r = 1;
} else {
try {
// indexed, but no tagName (element) or alert (window)
if ("length" in o && !("tagName" in o) && !("alert" in o) &&
(!Y.Lang.isFunction(o.size) || o.size() > 1)) {
r = 2;
}
} catch(e) {}
}
}
return r;
};
/**
* Executes the supplied function on each item in the array.
* @method Array.each
* @param a {Array} the array to iterate
* @param f {Function} the function to execute on each item
* @param o Optional context object
* @static
* @return {YUI} the YUI instance
*/
A.each = (Native.forEach) ?
function (a, f, o) {
Native.forEach.call(a || [], f, o || Y);
return Y;
} :
function (a, f, o) {
var l = (a && a.length) || 0, i;
for (i = 0; i < l; i=i+1) {
f.call(o || Y, a[i], i, a);
}
return Y;
};
/**
* Returns an object using the first array as keys, and
* the second as values. If the second array is not
* provided the value is set to true for each.
* @method Array.hash
* @static
* @param k {Array} keyset
* @param v {Array} optional valueset
* @return {object} the hash
*/
A.hash = function(k, v) {
var o = {}, l = k.length, vl = v && v.length, i;
for (i=0; i<l; i=i+1) {
o[k[i]] = (vl && vl > i) ? v[i] : true;
}
return o;
};
/**
* Returns the index of the first item in the array
* that contains the specified value, -1 if the
* value isn't found.
* @method Array.indexOf
* @static
* @param a {Array} the array to search
* @param val the value to search for
* @return {int} the index of the item that contains the value or -1
*/
A.indexOf = (Native.indexOf) ?
function(a, val) {
return a.indexOf(val);
} :
function(a, val) {
for (var i=0; i<a.length; i=i+1) {
if (a[i] === val) {
return i;
}
}
return -1;
};
/**
* Numeric sort convenience function.
* Y.ArrayAssert.itemsAreEqual([1, 2, 3], [3, 1, 2].sort(Y.Array.numericSort));
* @method numericSort
*/
A.numericSort = function(a, b) {
return (a - b);
};
})();