Le 31 mai 2010 à 10:25, julius a écrit : > > On 31 May 2010, at 01:42, John Joyce wrote: > >> >> On May 30, 2010, at 5:15 PM, julius wrote: >> >>> John hi >>> On 30 May 2010, at 19:47, John Joyce wrote: >>> >>>> That's not how these constants work. >>>> These are intended to be constants that return the correct type for the >>>> current build of the system. >>>> This protects your software from a change in the actual UTI of a common >>>> type. >>>> >>> >>> I can understand the use of constants to such a purpose. >>> Hence for instance my ability to write a file as NSRTFTextDocumentType when >>> in the Save panel I have opted to save it as com.apple.rtfd or as a >>> document having no UTI at all. >>> >>> If I read a document for which I have declared no UTI then the ofType >>> parameter in the readFromData:ofType:error: displays the Name I have used >>> to describe that document type. On the other hand if I have used a UTI then >>> it is the UTI that is passed as the ofType parameter. >>> >>> So if I have this correctly, in the case of files that will only ever be >>> read by my application it really does not matter what extension or UTI I >>> give them since it is the responsibility of my code to make sense of them. >>> However, if I want to write files that other applications can read I have >>> not only to provide the correct format but also the correct extension or >>> UTI . Is it therefore the case that when writing files to be read by other >>> applications I need not only write using the correct >>> NSDocumentTypeDocumentAttribute but also provide the correct UTI (or >>> extension)? If so then surely I need to have an idea of which UTI's (if >>> any) go with a given NSDocumentTypeDocumentAttribute? >>> >>> Thanks >>> Julius >>> >>> >>> http://juliuspaintings.co.uk >>> >> Your application declares the types of files it can read and/or edit. >> It declares these types by UTI. > > That is what I thought. >> >> If an application declares that it can read files of type x, then you can >> definitely open files of type x with that application. >> >> Not all UTIs are built in the OS. >> They're "registered" with the OS. >> The OS does not know about many (most?) file types out of the box. > That too is my understanding >> >> The OS can attempt to identify a file's type. >> It doesn't always know 100% what app should or could open a file or edit it. >> It will then give you a choice of "Recommended applications", that is, apps >> that are declared to read or edit a file of the UTI that the OS thinks this >> file might be. The OS does allow the user to choose from "All Applications" >> also, because the OS cannot realistically know about all file types ahead of >> time. > Which is why (I think I correctly assume) one's program has to make decisions > regarding how to handle incoming or outgoing file data on the basis of the > ofType: parameter. >> >> This data is covered, but you may want to explore further the docs, a few >> books on cocoa, and sample apps from apple. >> Look at how they handle this. >> Ideally, look at open source or sample apps that handle similar file types >> to yours. > Yes. But I have!!!
And have you look at the way TextEdit do that ? Hint: TextEdit sources are in /Developer/Examples/ -- Jean-Daniel _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
