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

Writing the Document's Content

- canAsynchronouslyWriteToURL:ofType:forSaveOperation:

Returns whether the receiver can concurrently write to a file or file package located by a URL, that is formatted for a specific type, for a specific kind of save operation.

- unblockUserInteraction

Unblocks the main thread during asynchronous saving.

- writeToURL:ofType:error:

Writes the contents of the document to a file or file package located by a URL, that is formatted to a specified type.

- writeSafelyToURL:ofType:forSaveOperation:error:

Writes the contents of the document to a file or file package located by a URL.

- fileWrapperOfType:error:

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

- writeToURL:ofType:forSaveOperation:originalContentsURL:error:

Writes the contents of the document to a file or file package located by a URL.

- saveToURL:ofType:forSaveOperation:delegate:didSaveSelector:contextInfo:

Saves the contents of the document to a file or file package located by a URL, that is formatted to a specified type, for a particular kind of save operation.

- saveToURL:ofType:forSaveOperation:completionHandler:

Saves the contents of the document to a file or file package located by a URL, that is formatted to a specified type, for a particular kind of save operation, and invokes the passed-in completion handler.

- fileAttributesToWriteToURL:ofType:forSaveOperation:originalContentsURL:error:

Returns the attributes to write to the file or file package at the specified URL, and targeting the specified type of save operation.

NSSaveOperationType

Constants for specifying the type of document-save operation to perform.