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


func CFURLCopyResourcePropertyForKey(_ url: CFURL!, _ key: CFString!, _ propertyValueTypeRefPtr: UnsafeMutableRawPointer!, _ error: UnsafeMutablePointer<Unmanaged<CFError>?>!) -> Bool



The URL.


The property value key for the requested value.


The output pointer that is populated with the result.


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.


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 true 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 false, an error occurred. the object pointer referenced by error is populated with additional information.

See Also

Getting and Setting File System Resource Properties

func CFURLClearResourcePropertyCache(CFURL!)

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

func CFURLClearResourcePropertyCacheForKey(CFURL!, CFString!)

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

func CFURLCreateResourcePropertiesForKeysFromBookmarkData(CFAllocator!, CFArray!, CFData!) -> Unmanaged<CFDictionary>!

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

func CFURLSetResourcePropertiesForKeys(CFURL!, CFDictionary!, UnsafeMutablePointer<Unmanaged<CFError>?>!) -> Bool

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