…of collision between user data and internal data. Fixes #6968.
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,7 +1,6 @@ | ||
| (function( jQuery ) { | ||
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| var rbrace = /^(?:\{.*\}|\[.*\])$/; | ||
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| jQuery.extend({ | ||
| cache: {}, | ||
| @@ -23,110 +22,163 @@ jQuery.extend({ | ||
| }, | ||
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| hasData: function( elem ) { | ||
| elem = elem.nodeType ? jQuery.cache[ elem[jQuery.expando] ] : elem[ jQuery.expando ]; | ||
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| return !!elem && !jQuery.isEmptyObject(elem); | ||
| }, | ||
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| data: function( elem, name, data, pvt /* Internal Use Only */ ) { | ||
| if ( !jQuery.acceptData( elem ) ) { | ||
| return; | ||
| } | ||
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| var internalKey = jQuery.expando, getByName = typeof name === "string", thisCache, | ||
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| // 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, | ||
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| // 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, | ||
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| // 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; | ||
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| // 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 ) { | ||
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dmethvin
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| return; | ||
| } | ||
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| 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; | ||
| } | ||
| } | ||
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| if ( !cache[ id ] ) { | ||
| cache[ id ] = {}; | ||
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| } | ||
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| // 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" ) { | ||
| if ( pvt ) { | ||
| cache[ id ][ internalKey ] = jQuery.extend(cache[ id ][ internalKey ], name); | ||
| } else { | ||
| cache[ id ] = jQuery.extend(cache[ id ], name); | ||
| } | ||
| } | ||
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| thisCache = cache[ id ]; | ||
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| // 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 ] = {}; | ||
| } | ||
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| thisCache = thisCache[ internalKey ]; | ||
| } | ||
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| if ( data !== undefined ) { | ||
| thisCache[ name ] = data; | ||
| } | ||
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| return getByName ? thisCache[ name ] : thisCache; | ||
| }, | ||
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| removeData: function( elem, name, pvt /* Internal Use Only */ ) { | ||
| if ( !jQuery.acceptData( elem ) ) { | ||
| return; | ||
| } | ||
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| var internalKey = jQuery.expando, isNode = elem.nodeType, | ||
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| // See jQuery.data for more information | ||
| cache = isNode ? jQuery.cache : elem, | ||
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| // See jQuery.data for more information | ||
| id = isNode ? elem[ jQuery.expando ] : jQuery.expando; | ||
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| // If there is already no cache entry for this object, there is no | ||
| // purpose in continuing | ||
| if ( !cache[ id ] ) { | ||
| return; | ||
| } | ||
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| if ( name ) { | ||
| var thisCache = pvt ? cache[ id ][ internalKey ] : cache[ id ]; | ||
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| if ( thisCache ) { | ||
| delete thisCache[ name ]; | ||
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| // If there is no data left in the cache, we want to continue | ||
| // and let the cache object itself get destroyed | ||
| if ( !jQuery.isEmptyObject(thisCache) ) { | ||
| return; | ||
| } | ||
| } | ||
| } | ||
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| // See jQuery.data for more information | ||
| if ( pvt ) { | ||
| delete cache[ id ][ internalKey ]; | ||
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| // Don't destroy the parent cache unless the internal data object | ||
| // had been the only thing left in it | ||
| if ( !jQuery.isEmptyObject(cache[ id ]) ) { | ||
| return; | ||
| } | ||
| } | ||
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| var internalCache = cache[ id ][ internalKey ]; | ||
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| // 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; | ||
| } | ||
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| // 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 ] = {}; | ||
| cache[ id ][ internalKey ] = internalCache; | ||
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| // 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; | ||
| } | ||
| } | ||
| }, | ||
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| // For internal use only. | ||
| _data: function( elem, name, data ) { | ||
| return jQuery.data( elem, name, data, true ); | ||
| }, | ||
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| // A method for determining if a DOM node can handle the data expando | ||
| acceptData: function( elem ) { | ||
| if ( elem.nodeName ) { | ||
5 comments
on commit 8e59a99
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Have you tested the impact on performance of such change? You are adding one more function call when using jQuery._data() instead of jQuery.data().
In places were performance is critical, we should probably use the old jQuery.data with true as the last argument, shouldn't we?
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And what does "Internal Use Only" really means? Should plugin developers use it?
Has it been documented somewhere?
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@lrbabe, our intent with jQuery._data() is to prevent name collisions between internal jQuery data and external data attached by user code or plugins. Plugin developers should continue to use jQuery.data() or $().data() but of course they can use their own conventions to avoid collisions there, such as prepending "myPlugin" to the name of each data item or creating a master "myPlugin" object that contains all the data.
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Thank you for these explanations @dmethvin.
What about always passing true (or 1 if we're concerned about filesize) as a fourth param instead of using _data and adding unnecessary function calls?
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@lrbabe, we discussed and didn't think an extra function call would make too much difference. If you'd like to create some benchmarks to show a performance hit, we could take a look.
We are having problems with this line on IE7. I have an empty DOM node that I've inserted into the page with a jQuery template. I call empty() on it, and-- on IE7-- it croaks. Actually, it seems like it works once, but then not the second time, but I don't have a good Javascript tracing setup working, and using alerts() doesn't work, since this method appears to be called 100s of times.
I'm getting the IE equivalent of a NPE. In our case, it appears that cache[id] is not set, even though pvt and id are, and therefore we are getting an error.
Anyway, I am able to "fix" the problem by substituting "(!cache[id] || !cache[id][internalKey])"
I have no idea if this is right.
Would appreciate some guidance. I'm not sure what is actually necessary to reproduce and test, since I'm not familiar with the intent of this code.