Function

CFURLCopyResourcePropertyForKey

Returns the value of a given resource property of a given URL.

Declaration

Boolean CFURLCopyResourcePropertyForKey(CFURLRef url, CFStringRef key, void *propertyValueTypeRefPtr, CFErrorRef *error);

Parameters

url

The URL.

key

The property value key for the requested value.

propertyValueTypeRefPtr

The output pointer that is populated with the result.

error

The error that occurred if the property’s value could not be obtained. This parameter is optional. If you are not interested in receiving error information, you can pass NULL.

Return Value

true if propertyValueTypeRefPtr is successfully populated; otherwise, false.

Discussion

This function first checks if the URL object already caches the resource value. If so, it returns the cached resource value to the caller. If not, then this function synchronously obtains the resource value from the backing store, adds the resource value to the URL object's cache, and returns the resource value to the caller.

The type of the returned resource value varies by resource property; for details, see the documentation for the key you want to access.

If this function returns YES and the propertyValueTypeRefPtr is populated with nil, it means that the resource property is not available for the specified resource, and that no errors occurred when determining that the resource property was unavailable.

If this function returns NO, an error occurred. the object pointer referenced by error is populated with additional information.

See Also

Getting and Setting File System Resource Properties

CFURLClearResourcePropertyCache

Removes all cached resource values and temporary resource values from the URL object.

CFURLClearResourcePropertyCacheForKey

Removes the cached resource value identified by a given key from the URL object.

CFURLCopyResourcePropertiesForKeys

Returns the resource values for the properties identified by specified array of keys.

CFURLCreateResourcePropertiesForKeysFromBookmarkData

Returns the resource values for properties identified by a specified array of keys contained in specified bookmark data.

CFURLCreateResourcePropertyForKeyFromBookmarkData

Returns the value of a resource property from specified bookmark data.

CFURLSetResourcePropertiesForKeys

Sets the URL’s resource properties for a given set of keys to a given set of values.

CFURLSetResourcePropertyForKey

Sets the URL’s resource property for a given key to a given value.

CFURLSetTemporaryResourcePropertyForKey

Sets a temporary resource value on the URL.