Returns state data of an incomplete download...
this data should be sufficient to resume/restart the
download using the
-initWithResumeData:delegate:path:
method. Returns nil if a resume is probably impossible. NB. You need to call -setDeletesFileUponFailure:
to turn off deletion if you wish to be able to resume an incomplete download.
Sets a flag to determine if downloaded file is be
deleted upon failure. This is YES by
default and needs to be set to NO if
you want to be able to attempt to resume a failed
download.
Sets the path to which the file is
downloaded. May be called (once only)
after initialisation of the receiver or when the
delegate receives a
-download:decideDestinationWithSuggestedFilename:
message. Appends a number to the filename if allowOverwrite is NO and a file already exists at path. See -download:didCreateDestination:
also.
Warning the underscore at the start of the
name of this instance variable indicates that, even
though it is not technically private, it is
intended for internal use within the package, and
you should not use the variable in other code.
Called when it's time to establish a name for the
downloaded file... the delegate may decide a
name by inspecting the response. The delegate
should call
-setDestination:allowOverwrite:
to set the filename to be used.
Called when a response is received.
Multiple responses may be received on the
same download (eg with server push) and the
delegate should be prepared to treat each
separately.
Called when a download is resuming from
previously stored data and a response
has been received from the server. The
startingBytes is the offset from which the
downloaded data will actually commence... and
may be zero if the entire download must be
redone.