define( [

  	"./core",

  	"./core/access",
  	"./data/var/dataPriv",
  	"./data/var/dataUser"
  ], function( jQuery, access, dataPriv, dataUser ) {
  
  "use strict";
  
  //	Implementation Summary
  //
  //	1. Enforce API surface and semantic compatibility with 1.9.x branch
  //	2. Improve the module's maintainability by reducing the storage
  //		paths to a single mechanism.
  //	3. Use the same single mechanism to support "private" and "user" data.
  //	4. _Never_ expose "private" data to user code (TODO: Drop _data, _removeData)
  //	5. Avoid exposing implementation details on user objects (eg. expando properties)
  //	6. Provide a clear path for implementation upgrade to WeakMap in 2014

  
  var rbrace = /^(?:\{[\w\W]*\}|\[[\w\W]*\])$/,

  	rmultiDash = /[A-Z]/g;

  function getData( data ) {
  	if ( data === "true" ) {
  		return true;

  	}

  	if ( data === "false" ) {
  		return false;

  	}

  	if ( data === "null" ) {
  		return null;

  	}

  	// Only convert to a number if it doesn't change the string
  	if ( data === +data + "" ) {
  		return +data;

  	}

  	if ( rbrace.test( data ) ) {
  		return JSON.parse( data );

  	}

  	return data;

  }

  function dataAttr( elem, key, data ) {
  	var name;

  	// If nothing was found internally, try to fetch any
  	// data from the HTML5 data-* attribute
  	if ( data === undefined && elem.nodeType === 1 ) {
  		name = "data-" + key.replace( rmultiDash, "-$&" ).toLowerCase();
  		data = elem.getAttribute( name );

  		if ( typeof data === "string" ) {
  			try {
  				data = getData( data );
  			} catch ( e ) {}

  			// Make sure we set the data so it isn't changed later
  			dataUser.set( elem, key, data );
  		} else {
  			data = undefined;

  		}
  	}

  	return data;

  }

  jQuery.extend( {

  	hasData: function( elem ) {

  		return dataUser.hasData( elem ) || dataPriv.hasData( elem );

  	},
  
  	data: function( elem, name, data ) {

  		return dataUser.access( elem, name, data );

  	},
  
  	removeData: function( elem, name ) {

  		dataUser.remove( elem, name );

  	},

  	// TODO: Now that all calls to _data and _removeData have been replaced
  	// with direct calls to dataPriv methods, these can be deprecated.

  	_data: function( elem, name, data ) {

  		return dataPriv.access( elem, name, data );

  	},
  
  	_removeData: function( elem, name ) {

  		dataPriv.remove( elem, name );

  	}

  } );

  jQuery.fn.extend( {

  	data: function( key, value ) {
  		var i, name, data,

  			elem = this[ 0 ],

  			attrs = elem && elem.attributes;

  		// Gets all values
  		if ( key === undefined ) {
  			if ( this.length ) {

  				data = dataUser.get( elem );

  				if ( elem.nodeType === 1 && !dataPriv.get( elem, "hasDataAttrs" ) ) {

  					i = attrs.length;
  					while ( i-- ) {

  						// Support: IE 11 only

  						// The attrs elements can be null (#14894)
  						if ( attrs[ i ] ) {
  							name = attrs[ i ].name;
  							if ( name.indexOf( "data-" ) === 0 ) {

  								name = jQuery.camelCase( name.slice( 5 ) );

  								dataAttr( elem, name, data[ name ] );
  							}
  						}
  					}

  					dataPriv.set( elem, "hasDataAttrs", true );

  				}
  			}
  
  			return data;
  		}
  
  		// Sets multiple values
  		if ( typeof key === "object" ) {

  			return this.each( function() {
  				dataUser.set( this, key );
  			} );

  		}

  		return access( this, function( value ) {
  			var data;
  
  			// The calling jQuery object (element matches) is not empty
  			// (and therefore has an element appears at this[ 0 ]) and the
  			// `value` parameter was not undefined. An empty jQuery object
  			// will result in `undefined` for elem = this[ 0 ] which will
  			// throw an exception if an attempt to read a data cache is made.
  			if ( elem && value === undefined ) {
  
  				// Attempt to get data from the cache
  				// The key will always be camelCased in Data
  				data = dataUser.get( elem, key );
  				if ( data !== undefined ) {
  					return data;
  				}
  
  				// Attempt to "discover" the data in
  				// HTML5 custom data-* attrs
  				data = dataAttr( elem, key );
  				if ( data !== undefined ) {
  					return data;
  				}
  
  				// We tried really hard, but the data doesn't exist.
  				return;
  			}

  			// Set the data...
  			this.each( function() {

  				// We always store the camelCased key
  				dataUser.set( this, key, value );
  			} );
  		}, null, value, arguments.length > 1, null, true );

  	},
  
  	removeData: function( key ) {

  		return this.each( function() {
  			dataUser.remove( this, key );
  		} );

  	}

  } );

  
  return jQuery;

  } );