/*
* YUI lang utils
* @module yui
* @submodule lang
*/
YUI.add("lang", function(Y) {
/**
* Provides the language utilites and extensions used by the library
* @class Lang
* @static
*/
Y.Lang = Y.Lang || {};
var L = Y.Lang,
ARRAY_TOSTRING = '[object Array]',
FUNCTION_TOSTRING = '[object Function]',
STRING = 'string',
OBJECT = 'object',
BOOLEAN = 'boolean',
UNDEFINED = 'undefined',
OP = Object.prototype;
/**
* Determines whether or not the provided object is an array.
* Testing typeof/instanceof/constructor of arrays across frame
* boundaries isn't possible in Safari unless you have a reference
* to the other frame to test against its Array prototype. To
* handle this case, we test well-known array properties instead.
* properties.
* @TODO can we kill this cross frame hack?
* @method isArray
* @static
* @param o The object to test
* @return {boolean} true if o is an array
*/
L.isArray = function(o) {
return OP.toString.apply(o) === ARRAY_TOSTRING;
};
/**
* Determines whether or not the provided object is a boolean
* @method isBoolean
* @static
* @param o The object to test
* @return {boolean} true if o is a boolean
*/
L.isBoolean = function(o) {
return typeof o === BOOLEAN;
};
/**
* Determines whether or not the provided object is a function
* Note: Internet Explorer thinks certain functions are objects:
*
* var obj = document.createElement("object");
* Y.Lang.isFunction(obj.getAttribute) // reports false in IE
*
* var input = document.createElement("input"); // append to body
* Y.Lang.isFunction(input.focus) // reports false in IE
*
* You will have to implement additional tests if these functions
* matter to you.
*
* @method isFunction
* @static
* @param o The object to test
* @return {boolean} true if o is a function
*/
L.isFunction = function(o) {
return OP.toString.apply(o) === FUNCTION_TOSTRING;
};
/**
* Determines whether or not the supplied object is a date instance
* @method isDate
* @static
* @param o The object to test
* @return {boolean} true if o is a date
*/
L.isDate = function(o) {
return o instanceof Date;
};
/**
* Determines whether or not the provided object is null
* @method isNull
* @static
* @param o The object to test
* @return {boolean} true if o is null
*/
L.isNull = function(o) {
return o === null;
};
/**
* Determines whether or not the provided object is a legal number
* @method isNumber
* @static
* @param o The object to test
* @return {boolean} true if o is a number
*/
L.isNumber = function(o) {
return typeof o === 'number' && isFinite(o);
};
/**
* Determines whether or not the provided object is of type object
* or function
* @method isObject
* @static
* @param o The object to test
* @param failfn {boolean} fail if the input is a function
* @return {boolean} true if o is an object
*/
L.isObject = function(o, failfn) {
return (o && (typeof o === OBJECT || (!failfn && L.isFunction(o)))) || false;
};
/**
* Determines whether or not the provided object is a string
* @method isString
* @static
* @param o The object to test
* @return {boolean} true if o is a string
*/
L.isString = function(o) {
return typeof o === STRING;
};
/**
* Determines whether or not the provided object is undefined
* @method isUndefined
* @static
* @param o The object to test
* @return {boolean} true if o is undefined
*/
L.isUndefined = function(o) {
return typeof o === UNDEFINED;
};
/**
* Returns a string without any leading or trailing whitespace. If
* the input is not a string, the input will be returned untouched.
* @method trim
* @static
* @param s {string} the string to trim
* @return {string} the trimmed string
*/
L.trim = function(s){
try {
return s.replace(/^\s+|\s+$/g, "");
} catch(e) {
return s;
}
};
/**
* A convenience method for detecting a legitimate non-null value.
* Returns false for null/undefined/NaN, true for other values,
* including 0/false/''
* @method isValue
* @static
* @param o The item to test
* @return {boolean} true if it is not null/undefined/NaN || false
*/
L.isValue = function(o) {
// return (o || o === false || o === 0 || o === ''); // Infinity fails
return (L.isObject(o) || L.isString(o) || L.isNumber(o) || L.isBoolean(o));
};
}, "@VERSION@");