jquery/src/data.js

326 lines
8.8 KiB
JavaScript

(function( jQuery ) {
var rbrace = /^(?:\{.*\}|\[.*\])$/,
rmultiDash = /([a-z])([A-Z])/g;
jQuery.extend({
cache: {},
// Please use with caution
uuid: 0,
// Unique for each copy of jQuery on the page
// Non-digits removed to match rinlinejQuery
expando: "jQuery" + ( jQuery.fn.jquery + Math.random() ).replace( /\D/g, "" ),
// The following elements throw uncatchable exceptions if you
// attempt to add expando properties to them.
noData: {
"embed": true,
// Ban all objects except for Flash (which handle expandos)
"object": "clsid:D27CDB6E-AE6D-11cf-96B8-444553540000",
"applet": true
},
hasData: function( elem ) {
elem = elem.nodeType ? jQuery.cache[ elem[jQuery.expando] ] : elem[ jQuery.expando ];
return !!elem && !isEmptyDataObject( elem );
},
data: function( elem, name, data, pvt /* Internal Use Only */ ) {
if ( !jQuery.acceptData( elem ) ) {
return;
}
var internalKey = jQuery.expando, getByName = typeof name === "string", thisCache,
// We have to handle DOM nodes and JS objects differently because IE6-7
// can't GC object references properly across the DOM-JS boundary
isNode = elem.nodeType,
// Only DOM nodes need the global jQuery cache; JS object data is
// attached directly to the object so GC can occur automatically
cache = isNode ? jQuery.cache : elem,
// Only defining an ID for JS objects if its cache already exists allows
// the code to shortcut on the same path as a DOM node with no cache
id = isNode ? elem[ jQuery.expando ] : elem[ jQuery.expando ] && jQuery.expando;
// Avoid doing any more work than we need to when trying to get data on an
// object that has no data at all
if ( (!id || (pvt && id && !cache[ id ][ internalKey ])) && getByName && data === undefined ) {
return;
}
if ( !id ) {
// Only DOM nodes need a new unique ID for each element since their data
// ends up in the global cache
if ( isNode ) {
elem[ jQuery.expando ] = id = ++jQuery.uuid;
} else {
id = jQuery.expando;
}
}
if ( !cache[ id ] ) {
cache[ id ] = {};
// TODO: This is a hack for 1.5 ONLY. Avoids exposing jQuery
// metadata on plain JS objects when the object is serialized using
// JSON.stringify
if ( !isNode ) {
cache[ id ].toJSON = jQuery.noop;
}
}
// An object can be passed to jQuery.data instead of a key/value pair; this gets
// shallow copied over onto the existing cache
if ( typeof name === "object" || typeof name === "function" ) {
if ( pvt ) {
cache[ id ][ internalKey ] = jQuery.extend(cache[ id ][ internalKey ], name);
} else {
cache[ id ] = jQuery.extend(cache[ id ], name);
}
}
thisCache = cache[ id ];
// Internal jQuery data is stored in a separate object inside the object's data
// cache in order to avoid key collisions between internal data and user-defined
// data
if ( pvt ) {
if ( !thisCache[ internalKey ] ) {
thisCache[ internalKey ] = {};
}
thisCache = thisCache[ internalKey ];
}
if ( data !== undefined ) {
thisCache[ jQuery.camelCase( name ) ] = data;
}
// TODO: This is a hack for 1.5 ONLY. It will be removed in 1.6. Users should
// not attempt to inspect the internal events object using jQuery.data, as this
// internal data object is undocumented and subject to change.
if ( name === "events" && !thisCache[name] ) {
return thisCache[ internalKey ] && thisCache[ internalKey ].events;
}
return getByName ? thisCache[ jQuery.camelCase( name ) ] : thisCache;
},
removeData: function( elem, name, pvt /* Internal Use Only */ ) {
if ( !jQuery.acceptData( elem ) ) {
return;
}
var internalKey = jQuery.expando, isNode = elem.nodeType,
// See jQuery.data for more information
cache = isNode ? jQuery.cache : elem,
// See jQuery.data for more information
id = isNode ? elem[ jQuery.expando ] : jQuery.expando;
// If there is already no cache entry for this object, there is no
// purpose in continuing
if ( !cache[ id ] ) {
return;
}
if ( name ) {
var thisCache = pvt ? cache[ id ][ internalKey ] : cache[ id ];
if ( thisCache ) {
delete thisCache[ name ];
// If there is no data left in the cache, we want to continue
// and let the cache object itself get destroyed
if ( !isEmptyDataObject(thisCache) ) {
return;
}
}
}
// See jQuery.data for more information
if ( pvt ) {
delete cache[ id ][ internalKey ];
// Don't destroy the parent cache unless the internal data object
// had been the only thing left in it
if ( !isEmptyDataObject(cache[ id ]) ) {
return;
}
}
var internalCache = cache[ id ][ internalKey ];
// Browsers that fail expando deletion also refuse to delete expandos on
// the window, but it will allow it on all other JS objects; other browsers
// don't care
if ( jQuery.support.deleteExpando || cache != window ) {
delete cache[ id ];
} else {
cache[ id ] = null;
}
// We destroyed the entire user cache at once because it's faster than
// iterating through each key, but we need to continue to persist internal
// data if it existed
if ( internalCache ) {
cache[ id ] = {};
// TODO: This is a hack for 1.5 ONLY. Avoids exposing jQuery
// metadata on plain JS objects when the object is serialized using
// JSON.stringify
if ( !isNode ) {
cache[ id ].toJSON = jQuery.noop;
}
cache[ id ][ internalKey ] = internalCache;
// Otherwise, we need to eliminate the expando on the node to avoid
// false lookups in the cache for entries that no longer exist
} else if ( isNode ) {
// IE does not allow us to delete expando properties from nodes,
// nor does it have a removeAttribute function on Document nodes;
// we must handle all of these cases
if ( jQuery.support.deleteExpando ) {
delete elem[ jQuery.expando ];
} else if ( elem.removeAttribute ) {
elem.removeAttribute( jQuery.expando );
} else {
elem[ jQuery.expando ] = null;
}
}
},
// For internal use only.
_data: function( elem, name, data ) {
return jQuery.data( elem, name, data, true );
},
// A method for determining if a DOM node can handle the data expando
acceptData: function( elem ) {
if ( elem.nodeName ) {
var match = jQuery.noData[ elem.nodeName.toLowerCase() ];
if ( match ) {
return !(match === true || elem.getAttribute("classid") !== match);
}
}
return true;
}
});
jQuery.fn.extend({
data: function( key, value ) {
var data = null;
if ( typeof key === "undefined" ) {
if ( this.length ) {
data = jQuery.data( this[0] );
if ( this[0].nodeType === 1 ) {
var attr = this[0].attributes, name;
for ( var i = 0, l = attr.length; i < l; i++ ) {
name = attr[i].name;
if ( name.indexOf( "data-" ) === 0 ) {
name = jQuery.camelCase( name.substring(5) );
dataAttr( this[0], name, data[ name ] );
}
}
}
}
return data;
} else if ( typeof key === "object" ) {
return this.each(function() {
jQuery.data( this, key );
});
}
var parts = key.split(".");
parts[1] = parts[1] ? "." + parts[1] : "";
if ( value === undefined ) {
data = this.triggerHandler("getData" + parts[1] + "!", [parts[0]]);
// Try to fetch any internally stored data first
if ( data === undefined && this.length ) {
data = jQuery.data( this[0], key );
data = dataAttr( this[0], key, data );
}
return data === undefined && parts[1] ?
this.data( parts[0] ) :
data;
} else {
return this.each(function() {
var $this = jQuery( this ),
args = [ parts[0], value ];
$this.triggerHandler( "setData" + parts[1] + "!", args );
jQuery.data( this, key, value );
$this.triggerHandler( "changeData" + parts[1] + "!", args );
});
}
},
removeData: function( key ) {
return this.each(function() {
jQuery.removeData( this, key );
});
}
});
function dataAttr( elem, key, data ) {
// If nothing was found internally, try to fetch any
// data from the HTML5 data-* attribute
if ( data === undefined && elem.nodeType === 1 ) {
var name = "data-" + key.replace( rmultiDash, "$1-$2" ).toLowerCase();
data = elem.getAttribute( name );
if ( typeof data === "string" ) {
try {
data = data === "true" ? true :
data === "false" ? false :
data === "null" ? null :
!jQuery.isNaN( data ) ? parseFloat( data ) :
rbrace.test( data ) ? jQuery.parseJSON( data ) :
data;
} catch( e ) {}
// Make sure we set the data so it isn't changed later
jQuery.data( elem, key, data );
} else {
data = undefined;
}
}
return data;
}
// TODO: This is a hack for 1.5 ONLY to allow objects with a single toJSON
// property to be considered empty objects; this property always exists in
// order to make sure JSON.stringify does not expose internal metadata
function isEmptyDataObject( obj ) {
for ( var name in obj ) {
if ( name !== "toJSON" ) {
return false;
}
}
return true;
}
})( jQuery );