Version 3.18.1
Show:

Lang Class

Defined in: yui/js/yui-lang.js:9
Module: yui-base
Parent Module: yui

Provides core language utilites and extensions used throughout YUI.

Item Index

Methods

Methods

_isNative

(
  • fn
)
Boolean protected static

Defined in yui/js/yui-lang.js:45

Available since 3.5.0

Returns true if the given function appears to be implemented in native code, false otherwise. Will always return false -- even in ES5-capable browsers -- if the useNativeES5 YUI config option is set to false.

This isn't guaranteed to be 100% accurate and won't work for anything other than functions, but it can be useful for determining whether a function like Array.prototype.forEach is native or a JS shim provided by another library.

There's a great article by @kangax discussing certain flaws with this technique: http://perfectionkills.com/detecting-built-in-host-methods/

While his points are valid, it's still possible to benefit from this function as long as it's used carefully and sparingly, and in such a way that false negatives have minimal consequences. It's used internally to avoid using potentially broken non-native ES5 shims that have been added to the page by other libraries.

Parameters:

Returns:

Boolean:

true if fn appears to be native, false otherwise.

isArray

(
  • o
)
Boolean static

Determines whether or not the provided item is an array.

Returns false for array-like collections such as the function arguments collection or HTMLElement collections. Use Y.Array.test() if you want to test for an array-like collection.

Parameters:

  • o Object

    The object to test.

Returns:

Boolean:

true if o is an array.

isBoolean

(
  • o
)
Boolean static

Determines whether or not the provided item is a boolean.

Parameters:

  • o Object

    The object to test.

Returns:

Boolean:

true if o is a boolean.

isDate

(
  • o
)
Boolean static

Determines whether or not the supplied item is a date instance.

Parameters:

  • o Object

    The object to test.

Returns:

Boolean:

true if o is a date.

isFunction

(
  • o
)
Boolean static

Determines whether or not the provided item 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.

Parameters:

  • o Object

    The object to test.

Returns:

Boolean:

true if o is a function.

isNull

(
  • o
)
Boolean static

Determines whether or not the provided item is null.

Parameters:

  • o Object

    The object to test.

Returns:

Boolean:

true if o is null.

isNumber

(
  • o
)
Boolean static

Determines whether or not the provided item is a legal number.

Parameters:

  • o Object

    The object to test.

Returns:

Boolean:

true if o is a number.

isObject

(
  • o
  • failfn
)
Boolean static

Determines whether or not the provided item is of type object or function. Note that arrays are also objects, so Y.Lang.isObject([]) === true.

Parameters:

  • o Object

    The object to test.

  • failfn Boolean

    fail if the input is a function.

Returns:

Boolean:

true if o is an object.

isRegExp

(
  • value
)
Boolean static

Determines whether or not the provided value is a regexp.

Parameters:

  • value Object

    The value or object to test.

Returns:

Boolean:

true if value is a regexp.

isString

(
  • o
)
Boolean static

Determines whether or not the provided item is a string.

Parameters:

  • o Object

    The object to test.

Returns:

Boolean:

true if o is a string.

isUndefined

(
  • o
)
Boolean static

Determines whether or not the provided item is undefined.

Parameters:

  • o Object

    The object to test.

Returns:

Boolean:

true if o is undefined.

isValue

(
  • o
)
Boolean static

A convenience method for detecting a legitimate non-null value. Returns false for null/undefined/NaN, true for other values, including 0/false/''

Parameters:

Returns:

Boolean:

true if it is not null/undefined/NaN || false.

now

() Number static

Defined in yui/js/yui-lang.js:239

Available since 3.3.0

Returns the current time in milliseconds.

Returns:

Number:

Current time in milliseconds.

sub

(
  • s
  • o
)
String static

Defined in yui/js/yui-lang.js:251

Available since 3.2.0

Performs {placeholder} substitution on a string. The object passed as the second parameter provides values to replace the {placeholder}s. {placeholder} token names must match property names of the object. For example,

var greeting = Y.Lang.sub("Hello, {who}!", { who: "World" });

{placeholder} tokens that are undefined on the object map will be left in tact (leaving unsightly {placeholder}'s in the output string).

Parameters:

  • s String

    String to be modified.

  • o Object

    Object containing replacement values.

Returns:

String:

the substitute result.

trim

(
  • s
)
String static

Returns a string without any leading or trailing whitespace. If the input is not a string, the input will be returned untouched.

Parameters:

  • s String

    the string to trim.

Returns:

String:

the trimmed string.

trimLeft

(
  • s
)
String static

Returns a string without any leading whitespace.

Parameters:

  • s String

    the string to trim.

Returns:

String:

the trimmed string.

trimRight

(
  • s
)
String static

Returns a string without any trailing whitespace.

Parameters:

  • s String

    the string to trim.

Returns:

String:

the trimmed string.

type

(
  • o
)
String static

Returns one of the following strings, representing the type of the item passed in:

  • "array"
  • "boolean"
  • "date"
  • "error"
  • "function"
  • "null"
  • "number"
  • "object"
  • "regexp"
  • "string"
  • "undefined"

Known issues:

  • typeof HTMLElementCollection returns function in Safari, but Y.Lang.type() reports "object", which could be a good thing -- but it actually caused the logic in Y.Lang.isObject to fail.

Parameters:

Returns:

String:

the detected type.