NSDocument new file logic
Dear list, I have an NSPersistentDocument subclass which encapsulates a project for the user. When the user creates a new project, they specify a name and a location on disk. I then want to create a new instance of my NSDocument subclass as if it was saved exactly where the user wants it to be. I want to do this because the app then creates additional files (which are managed by the project -- think Xcode) which are placed in the same location as the project file. In the past I achieved this in a somewhat unsatisfactory way by just calling newDocument: then saveDocument: and getting the user to immediately save the document before the app does the rest of the setup steps. This was working, but it does mean that the user is immediately presented with a save panel, which is not so nice. I'd rather present a custom panel telling them to enter a project name and a location on disk. Anyway, that aside, this scheme doesn't seem robust to future OS implementations (maybe the saveDocument: behaviour changes, for example). What I'd really like is an NSDocumentController method like -(id)createDocumentAtURL:(NSURL*)aURL ofType:(NSString*)type error:(NSError**)anError; but that doesn't seem to exist. Can anyone recommend a way to do what I want? In other words, to programmatically create an NSDocument instance already saved on disk? This behaviour is essentially what Xcode is doing when one creates a new project. Best wishes, Martin Martin Hewitson Albert-Einstein-Institut Max-Planck-Institut fuer Gravitationsphysik und Universitaet Hannover Callinstr. 38, 30167 Hannover, Germany Tel: +49-511-762-17121, Fax: +49-511-762-5861 E-Mail: martin.hewit...@aei.mpg.de WWW: http://www.aei.mpg.de/~hewitson ___ 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
Re: NSDocument new file logic
On Jun 28, 2011, at 23:58, Martin Hewitson wrote:
In the past I achieved this in a somewhat unsatisfactory way by just calling
newDocument: then saveDocument: and getting the user to immediately save the
document before the app does the rest of the setup steps.
Using the action methods (newDocument: and saveDocument:) is what makes your
approach unappealing for the user. In Snow Leopard or earlier, for a regular
document, the steps are something like this:
1. Get the project name and file system location. (You can use the Save panel
for this, but you put it up yourself rather than having 'newDocument:' do it.
Or, you can use some kind of custom dialog.)
2. Create a document file at that location. (Typically, you create a default
data model or import some data, turn it into a keyed archive, write the archive
data to a file.)
3. Use NSDocumentController's 'openDocumentWithContentsOfURL:display:error:'
method to open the now-existing document normally.
You can use much the same approach for NSPersistentDocument, but step 2 is a
little different. Here's a method I wrote (based on some sample code somewhere
in the Core Data documentation, but I don't remember where) that creates a new
store. It returns a managed object context because you probably want to put
something in the store (and 'save:' it) before re-opening it as a
NSPersistentDocument in step 3.
+ (NSManagedObjectContext*) managedObjectContextForStoreURL: (NSURL*) storeURL
{
// Find the document's model
NSManagedObjectModel* model = [NSManagedObjectModel
mergedModelFromBundles: nil];
if (!model)
return nil;
// Create a persistent store
NSPersistentStoreCoordinator* psc = [[NSPersistentStoreCoordinator
alloc] initWithManagedObjectModel: model];
if (!psc)
return nil;
NSError* error;
NSPersistentStore* store = [psc addPersistentStoreWithType:
NSSQLiteStoreType
configuration: nil
URL: storeURL
options: nil
error: error];
if (!store)
return nil;
// Create a managed object context for the store
NSManagedObjectContext* managedContext = [[NSManagedObjectContext
alloc] init];
if (!managedContext)
return nil;
managedContext.persistentStoreCoordinator = psc;
managedContext.undoManager = nil;
return managedContext;
}
HTH
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Re: NSDocument new file logic
Wonderful! Thanks very much. I will give this a try. Writing out the core data
store was the bit I was missing.
Martin
On Jun 29, 2011, at 9:54 AM, Quincey Morris wrote:
On Jun 28, 2011, at 23:58, Martin Hewitson wrote:
In the past I achieved this in a somewhat unsatisfactory way by just calling
newDocument: then saveDocument: and getting the user to immediately save the
document before the app does the rest of the setup steps.
Using the action methods (newDocument: and saveDocument:) is what makes your
approach unappealing for the user. In Snow Leopard or earlier, for a regular
document, the steps are something like this:
1. Get the project name and file system location. (You can use the Save panel
for this, but you put it up yourself rather than having 'newDocument:' do it.
Or, you can use some kind of custom dialog.)
2. Create a document file at that location. (Typically, you create a default
data model or import some data, turn it into a keyed archive, write the
archive data to a file.)
3. Use NSDocumentController's 'openDocumentWithContentsOfURL:display:error:'
method to open the now-existing document normally.
You can use much the same approach for NSPersistentDocument, but step 2 is a
little different. Here's a method I wrote (based on some sample code
somewhere in the Core Data documentation, but I don't remember where) that
creates a new store. It returns a managed object context because you probably
want to put something in the store (and 'save:' it) before re-opening it as a
NSPersistentDocument in step 3.
+ (NSManagedObjectContext*) managedObjectContextForStoreURL: (NSURL*)
storeURL
{
// Find the document's model
NSManagedObjectModel* model = [NSManagedObjectModel
mergedModelFromBundles: nil];
if (!model)
return nil;
// Create a persistent store
NSPersistentStoreCoordinator* psc = [[NSPersistentStoreCoordinator
alloc] initWithManagedObjectModel: model];
if (!psc)
return nil;
NSError* error;
NSPersistentStore* store = [psc addPersistentStoreWithType:
NSSQLiteStoreType
configuration: nil
URL: storeURL
options: nil
error: error];
if (!store)
return nil;
// Create a managed object context for the store
NSManagedObjectContext* managedContext = [[NSManagedObjectContext
alloc] init];
if (!managedContext)
return nil;
managedContext.persistentStoreCoordinator = psc;
managedContext.undoManager = nil;
return managedContext;
}
HTH
Martin Hewitson
Albert-Einstein-Institut
Max-Planck-Institut fuer
Gravitationsphysik und Universitaet Hannover
Callinstr. 38, 30167 Hannover, Germany
Tel: +49-511-762-17121, Fax: +49-511-762-5861
E-Mail: martin.hewit...@aei.mpg.de
WWW: http://www.aei.mpg.de/~hewitson
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