Instance Method

dataOfType:error:

Creates and returns a data object that contains the contents of the document, formatted to a specified type.

Declaration

- (NSData *)dataOfType:(NSString *)typeName error:(NSError * _Nullable *)outError;

Parameters

typeName

The string that identifies the document type.

outError

On return, if the data object could not be created, a pointer to an error object that encapsulates the reason it could not be created.

Return Value

A data object containing the document contents, or, if the data object could not be created, nil.

Discussion

The default implementation of this method throws an exception because at least one of the writing methods (this method, writeToURL:ofType:error:, fileWrapperOfType:error:, or writeToURL:ofType:forSaveOperation:originalContentsURL:error:) must be overridden.

For backward binary compatibility with OS X v10.3 and earlier, the default implementation of this method instead invokes dataRepresentationOfType:typeName on self if dataRepresentationOfType: is overridden.

See Also

Loading Document Data

- fileWrapperOfType:error:

Creates and returns a file wrapper that contains the contents of the document, formatted to the specified type.

- readFromData:ofType:error:

Sets the contents of this document by reading from data of a specified type and returns YES if successful.

entireFileLoaded

A Boolean value indicating whether the document’s file is completely loaded into memory.