- // Avoid generating a new cache unless none exists and we
- // want to manipulate it.
- if ( cache[ id ] ) {
- thisCache = cache[ id ];
- } else if ( typeof data === "undefined" ) {
- thisCache = emptyObject;
- } else {
- thisCache = cache[ id ] = {};
+ 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 ];