# Yahoo! UI Library

### yuiloader 2.5.0

Yahoo! UI Library > yuiloader > YAHOO.util.YUILoader

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## Class YAHOO.util.YUILoader

YUILoader provides dynamic loading for YUI.

### Properties

#### _internalCallback `- private object`

Internal callback to handle multiple internal insert() calls so that css is inserted prior to js

#### _useYahooListener `- private object`

Use the YAHOO environment listener to detect script load. This is only switched on for Safari 2.x and below.

#### allowRollup `- boolean`

Should we allow rollups
Default Value: true

#### base `- string`

The base directory.
Default Value: http://yui.yahooapis.com/[YUI VERSION]/build/

#### data `- object`

Data that is passed to all callbacks

#### dirty `- boolean`

Flag to indicate the dependency tree needs to be recomputed if insert is called again.
Default Value: true

#### filter `- string|{searchExp: string, replaceStr: string}`

A filter to apply to result urls. This filter will modify the default path for all modules. The default path for the YUI library is the minified version of the files (e.g., event-min.js). The filter property can be a predefined filter or a custom filter. The valid predefined filters are:

DEBUG
  Selects the debug versions of the library (e.g., event-debug.js). This option will automatically include the logger widget
RAW
  Selects the non-minified version of the library (e.g., event.js).

You can also define a custom filter, which must be an object literal containing a search expression and a replace string:

    myFilter: {
    'searchExp': "-min\\.js",
    'replaceStr': "-debug.js"
    }

#### force `- string`

A list of modules that should always be loaded, even if they have already been inserted into the page.

#### ignore `- string[]`

A list of modules that should not be loaded, even if they turn up in the dependency tree

#### inserted `- {string: boolean}`

List of modules inserted by the utility

#### loaded `- {string: boolean}`

Set when beginning to compute the dependency tree. Composed of what YAHOO reports to be loaded combined with what has been loaded by the tool

#### loadOptional `- boolean`

Whether or not to load optional dependencies for the requested modules
Default Value: false

#### moduleInfo `- object`

The library metadata

#### required `- {string: boolean}`

The list of requested modules

#### rollups `- object`

List of rollup files found in the library metadata

#### scope `- object`

The execution scope for all callbacks
Default Value: this

#### skin `- object`

Provides the information used to skin the skinnable components. The following skin definition would result in 'skin1' and 'skin2' being loaded for calendar (if calendar was requested), and 'sam' for all other skinnable components: `skin: { // The default skin, which is automatically applied if not // overriden by a component-specific skin definition. // Change this in to apply a different skin globally defaultSkin: 'sam', // This is combined with the loader base property to get // the default root directory for a skin. ex: // http://yui.yahooapis.com/2.3.0/build/assets/skins/sam/ base: 'assets/skins/', // The name of the rollup css file for the skin path: 'skin.css', // The number of skinnable components requested that are // required before using the rollup file rather than the // individual component css files rollup: 3, // Any component-specific overrides can be specified here, // making it possible to load different skins for different // components. It is possible to load more than one skin // for a given component as well. overrides: { calendar: ['skin1', 'skin2'] } }`

#### sorted `- string[]`

All of the derived dependencies in sorted order, which will be populated when either calculate() or insert() is called

#### varName `- string`

The name of the variable in a sandbox or script node (for external script support in Safari 2.x and earlier) to reference when the load is complete. If this variable is not available in the specified scripts, the operation will fail.

### Methods

#### _addSkin

`private void _addSkin ( )`
Adds the skin def to the module info

Returns: `void`

#### _explode

`private void _explode ( )`
Inspects the required modules list looking for additional dependencies. Expands the required list to include all required modules. Called by calculate()

Returns: `void`

#### _pushEvents

`private void _pushEvents ( optional )`
In IE, the onAvailable/onDOMReady events need help when Event is loaded dynamically

Parameters:
  `optional <Function>` function reference

Returns: `void`

#### _reduce

`private void _reduce ( )`
Remove superceded modules and loaded modules. Called by calculate() after we have the mega list of all dependencies

Returns: `void`

#### _rollup

`private void _rollup ( )`
Look for rollup packages to determine if all of the modules a rollup supersedes are required. If so, include the rollup to help reduce the total number of connections required. Called by calculate()

Returns: `void`

#### _setup

`private void _setup ( )`
Investigates the current YUI configuration on the page. By default, modules already detected will not be loaded again unless a force option is encountered. Called by calculate()

Returns: `void`

#### _skin

`private void _skin ( )`
Sets up the requirements for the skin assets if any of the requested modules are skinnable

Returns: `void`

#### _sort

`private void _sort ( )`
Sorts the dependency tree. The last step of calculate()

Returns: `void`

#### _url

`private string _url ( path )`
Generates the full url for a module method _url

Parameters:
  `path <string>` the path fragment

Returns: `string`
  the full url

#### addModule

`boolean addModule ( o )`
Add a new module to the component metadata.

name:
  required, the component name
type:
  required, the component type (js or css)
path:
  required, the path to the script from "base"
requires:
  the modules required by this component
optional:
  the optional modules for this component
supersedes:
  the modules this component replaces
rollup:
  the number of superseded modules required for automatic rollup
fullpath:
  If fullpath is specified, this is used instead of the configured base + path
skinnable:
  flag to determine if skin assets should automatically be pulled in

Parameters:
  `o <object>` An object containing the module data

Returns: `boolean`
  true if the module was added, false if the object passed in did not provide all required attributes

#### calculate

`void calculate ( o )`
Calculates the dependency tree, the result is stored in the sorted property

Parameters:
  `o <object>` optional options object

Returns: `void`

#### formatSkin

`string formatSkin ( skin , mod )`
Returns the skin module name for the specified skin name. If a module name is supplied, the returned skin module name is specific to the module passed in.

Parameters:
  `skin <string>` the name of the skin
  `mod <string>` optional: the name of a module to skin

Returns: `string`
  the full skin module name

#### getProvides

`void getProvides ( mod )`
Returns an object literal of the modules the supplied module satisfies

Parameters:
  `mod <object>` The module definition from moduleInfo

Returns: `void`
  what this module provides

#### getRequires

`void getRequires ( mod )`
Returns an object containing properties for all modules required in order to load the requested module

Parameters:
  `mod <object>` The module definition from moduleInfo

Returns: `void`

#### insert

`void insert ( o , type )`
inserts the requested modules and their dependencies. `type` can be "js" or "css". Both script and css are inserted if type is not provided.

Parameters:
  `o <object>` optional options object
  `type <string>` the type of dependency to insert

Returns: `void`

#### loadNext

`void loadNext ( mname )`
Executed every time a module is loaded, and if we are in a load cycle, we attempt to load the next script. Public so that it is possible to call this if using a method other than YAHOO.register to determine when scripts are fully loaded

Parameters:
  `mname <string>` optional the name of the module that has been loaded (which is usually why it is time to load the next one)

Returns: `void`

#### onFailure

`void onFailure ( )`
Callback that will be executed if there is a failure

Returns: `void`

#### onProgress

`void onProgress ( )`
Callback that will be executed each time a new module is loaded

Returns: `void`

#### onSuccess

`void onSuccess ( )`
Callback that will be executed when the loader is finished with an insert

Returns: `void`

#### parseSkin

`skin: string, module: string parseSkin ( mod )`
Reverses `formatSkin`, providing the skin name and module name if the string matches the pattern for skins.

Parameters:
  `mod <string>` the module name to parse

Returns: `skin: string, module: string`
  the parsed skin name and module name, or null if the supplied string does not match the skin pattern

#### require

`void require ( what )`
Add a requirement for one or more module

Parameters:
  `what <string[] | string*>` the modules to load

Returns: `void`

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