CoreData questions: How to reset NSManagedObject, how to Un-manage an NSManagedObject.
Hi. 1. When you create an NSManagedObject, it is initialized with default values defined in the model. How can I reset an existing NSManagedObject to these default values? 2. We have a multithreaded application, and we only keep one core-data context. Our network-related code receives data in a background thread, but is unable to write it to the model directly. So it saves it in some intermediate data object, and passes it to the main-thread for writing into the model. I would like to use an NSManagedObject to replace the intermediate data object --- It is quite ugly to have duplicated model classes definition for everything. My question: Can I somehow detach an NSManagedObject from its context, and use it in an Unmanaged way? Hopefully I can later attach it to the context, or create another NSManagedOBject from its data? Motti Shneor, Spectrum Reflections LTD. --- ceterum censeo microsoftiem delendam esse --- ___ 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: design question
thank you very much for your answers. 2011/3/23 Graham Cox graham@bigpond.com On 23/03/2011, at 11:58 AM, Quincey Morris wrote: 1b. The property is a to-many relationship. If #1a, then the return value should be unchangeable, in the sense that it should never change after being returned (regardless of whether the returned object is of a mutable class or not). That means, if an existing mutable array is the desired return value, which the owning class might mutate later, a copy *must* be returned instead. If #1b, then the return value should be assumed to be changeable, in the sense that it could change any time after being returned. (Again, the return value's class's mutability is irrelevant.) *Semantically, what's being returned is a proxy for the relationship*, not an array. In this case, the return type merely indicates whether the caller can mutate the relationship via the proxy or not. In practice, it works in reverse. If the method returns something unchangeable, the property is regarded as an attribute. If it returns something changeable, the property is regarded as a to-many relationship. This is consistent with Core Data properties, and keeping the distinction clear keeps the API design honest and helps write correct code -- it makes it easy to decide whether to return a copy of the underlying array or not. Your discussion about how long and why has different answers depending on which of the two kinds of properties is involved. The pitfall here is that if the property is intended to be a snapshot of the state of a relationship (an attribute, as opposed to the actual relationship), returning the underlying mutable array without copying is a bug, even if the return type is NSArray. Right, and I agree. You've expressed it better than I did, sometimes it's hard to convey in writing something that you have only understood at some intuitive level. So this helps clarify something I hadn't made entirely clear in my own mind. The situation is #1b. And you know this, because you have more information than just a return type - you have the name of the method, -children. This pretty much tells you that you're dealing with a to-many relationship. If it doesn't, you've named it badly. Thus, a client can and should expect it to change, and so, if it actually wants a snapshot, it should perform the copy, but if not, it shouldn't cache it. Either way, in my view the onus is on the client as to whether to perform the copy - the vending object doesn't know what the client is going to use it for, so whether to copy it or not is not something it can know, so it should do the simplest thing (an instance of Occam's Razor?) which is, not copy. In practice, you rarely run into problems with this approach. I know everyone will have their favourite counter-examples, but that's why I say 'rarely', not 'never'. --Graham -- best regards Ariel ___ 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: CoreData questions: How to reset NSManagedObject, how to Un-manage an NSManagedObject.
On Mar 23, 2011, at 8:21 AM, Motti Shneor wrote:
Hi.
1. When you create an NSManagedObject, it is initialized with default values
defined in the model. How can I reset an existing NSManagedObject to these
default values?
Unless there is a better way, I would suggest to use a dictionary
representation of a freshly created managed object through taking a
snap-shot of this object using dictionaryWithValuesForKeys:. Then reset any
managed object by sending it setValuesForKeysWithDictionary:. You may declare
this dictionary as a class variable of your custom class and initialize it once
when you create the first managed object. You may get the key paths using the
entity description.
2. We have a multithreaded application, and we only keep one core-data
context. Our network-related code receives data in a background thread, but
is unable to write it to the model directly. So it saves it in some
intermediate data object, and passes it to the main-thread for writing into
the model.
I would like to use an NSManagedObject to replace the intermediate data
object --- It is quite ugly to have duplicated model classes definition for
everything. My question:
I wonder why you cannot modify the model (that is save a context) within the
background thread. Business logic should be honored regardless of the thread.
So, usually you would do the following:
Use one dedicated context for each thread. Your background thread imports new
objects and inserts (or modifies) it into its context, say import context. A
controller has registered (e.g. on the main thread) for context save
notifications (NSManagedObjectContextDidSaveNotification) sent from import
context. It also specifies a method to be invoked, say importContextDidSave::
// controller.m
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(importContextDidSave:)
name:NSManagedObjectContextDidSaveNotification
object:importContext];
When you are ready with importing, save the import context in the background
thread (or do it periodically if this is appropriate). When the context is
saved, the notification center invokes the registered method in your
controller. Upon receiving, you merge the import context with your main context
(which may be used for a table view), so basically:
- (void) importContextDidSave:(NSNotification*)saveNotification {
[mainContext mergeChangesFromContextDidSaveNotification:saveNotification];
}
Here, the current thread-context is irrelevant as long as you do not access the
managed objects directly which are accessible through the userInfo of the
saveNotification. Using mergeChangesFromContextDidSaveNotification:, the
context is able to safely merge the changes, regardless of the thread-context.
Note, that due to merging, the mainContext's state with respect to hasChanges
does not change.
Please note, that this background thread does not necessarily have to be the
same thread where you import data. It can be any worker thread, and it may
take any imported data objects from a fifo which are subsequently taken to
create managed objects. Also, this worker thread may take any actions to
perform additional validations or plausibility checks which may have prevented
the import thread to save these objects to the model.
Fortunately, there is quite good documentation for threading and Core Data.
Core Data Programming Guide, Concurrency with Core Data.
There are also good examples for this. Please take look. ;)
Can I somehow detach an NSManagedObject from its context, and use it in an
Unmanaged way?
No, a managed object must be registered with a managed object context.
Hopefully I can later attach it to the context, or create another
NSManagedOBject from its data?
You could use a dictionary representation and initialize a managed object from
it.
Regards
Andreas
Motti Shneor,
Spectrum Reflections LTD.
---
ceterum censeo microsoftiem delendam esse
---
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Re: How hidden the Keyboard in a UIWebView
Hi, sorry for this delay, I had to solve another thing. The reason of WHY i
am trying do this is because my boss say: DO IT!! Lol. I am doing a User
Manager so the user will not need to write in the keyboard and the system
will record the user name.
The UIWebView has a bad integration with keyboard and Java Script. And i
can't control the keyboard at all, I can only listen what it will do.
Ok, you give-me a start point. What I tried was:
- [myWebView
stringByEvaluatingJavaScriptFromString:@document.getElementsByName(myname)[0].onclick
= function onclick(event){document.getElementsByName(myname)[0].blur();};
Result: FAIL!! why? Because the cocoa first start to show the keyboard than
it will execute the JavaScript code. So, in the middle of animation, it run
and the keyboard return the animation and go out. I don't want it even start
to show.
The second way:
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWillShow:)
name:UIKeyboardWillShowNotification object:nil];
- (void)esconde {
for (UIWindow *keyboardWindow in [[UIApplication sharedApplication]
windows])
for (UIView *keyboard in [keyboardWindow subviews])
if([[keyboard description] hasPrefix:@UIPeripheralHostView]
== YES) [keyboard removeFromSuperview];
}
- (void)keyboardWillShow:(NSNotification *)aNotification {
[self performSelector:@selector(esconde) withObject:nil afterDelay:0];
}
Result: Well, work... But... It show the very start of the animation, but
the keyboard don't show. See that I NEED some delay, because this I use the
performSelector. I don't need more delay than the use of this way. If I use
the function directly, the UIPeripheralHostView will not exist. This way
is little dirty...
The problem to automatic focus a text box (it work) and than show the
keyboard isn't working.
How can I use the comand [keyboard showForFocusedTextBox]. Any more idea to
control the keyboard?
2011/3/15 Conrad Shultz con...@synthetiqsolutions.com
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
On 3/15/11 7:09 AM, Rodrigo Zanatta Silva wrote:
Anyone have any idea? I am stuck... It's easy do this with
UITextView, but the text field in a web page have less control. I
really need a new idea, please, anyone give-me a idea??!?!?
Please be patient. If no one responds, it's probably because they don't
have an idea either.
Lol.. I have to try..
2011/3/14 Rodrigo Zanatta Silva rodrigozanattasi...@gmail.com
I searched a lot, and all thing that hidden the keyboard is when
you are in a UITextField.
This is the problem. I am in a UIWebView and the user click in a
text box in the web page, so the iOS open the keyboard. I can know
when the keyboard will show by the UIKeyboardWillShowNotification.
But, I want to show another screen instead the keyboard.
Try not using a UIWebView? This whole scheme sounds a bit fishy to
me... if you are interfacing with a web service, for example, you should
probably implement a native UI and use XML, JSON, etc. to talk the the
site.
I do know that there are some reasons you would want to do this, such as
displaying a keypad for numeric entry. This _ought_ to be handled with
XHTML's inputmode attribute, which MobileSafari doesn't support.
For any Apple engineers out there, I filed a bug a long time ago on
this... rdar://6404093
How can I hidden, or never show the keyboard. If the people cancel
my screen, than I want to keyboard appear. There are any class that
I can manager the keyboard? How can I do this:
*[keyboard goWay]* and
*[keyboard show]*
I have no special insights on this, but you might check out
http://stackoverflow.com/questions/792035/how-do-i-cancel-a-text-field-edit-in-a-uiwebview
This purports to let you lose the keyboard via defocusing in JavaScript.
You would then probably need to present your own view for input on top
of/next to the UIWebView and write controller code to send it into the
UIWebView.
Also see
http://stackoverflow.com/questions/2749486/fill-uiwebview-textinput-with-custom-keyboard
Sounds like a huge headache to me, though, and again I question the
wisdom of what you are trying to do. Perhaps you can elaborate on WHY
you need to this and someone on the list might offer a more robust and
probably simpler solution.
- --
Conrad Shultz
Synthetiq Solutions
www.synthetiqsolutions.com
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Re: How hidden the Keyboard in a UIWebView
Rodrigo,
I'm not sure, even after reading your entire message, what you're trying to
accomplish. But, from what you mention, you seem to want to provide your boss
with a way to bypass some login screen or automatically enter a user name, is
that right?
I wrote an application which kind of does what you're trying to do. If you have
to show the login screen or the screen when the user name is entered, it will
not work. In my application, I have my own view for the user to enter his user
name. I even provide an option so that his user name is saved so that the next
time, I can retrieve it. Then, the trick is to keep the UIWebView hidden. You
just don't show it and using the stringByEvaluatingJavascriptFromString:, you
can provide the user name and even trigger the button that will allow the
login. From that point, when the UIWebView starts loading the next page after
the login, you can show it.
I can provide you more details privately if you're interested, just email me.
-Laurent.
--
Laurent Daudelin
AIM/iChat/Skype:LaurentDaudelin
http://www.nemesys-soft.com/
Logiciels Nemesys Software
laur...@nemesys-soft.com
On Mar 23, 2011, at 11:25, Rodrigo Zanatta Silva wrote:
Hi, sorry for this delay, I had to solve another thing. The reason of WHY i
am trying do this is because my boss say: DO IT!! Lol. I am doing a User
Manager so the user will not need to write in the keyboard and the system
will record the user name.
The UIWebView has a bad integration with keyboard and Java Script. And i
can't control the keyboard at all, I can only listen what it will do.
Ok, you give-me a start point. What I tried was:
- [myWebView
stringByEvaluatingJavaScriptFromString:@document.getElementsByName(myname)[0].onclick
= function onclick(event){document.getElementsByName(myname)[0].blur();};
Result: FAIL!! why? Because the cocoa first start to show the keyboard than
it will execute the JavaScript code. So, in the middle of animation, it run
and the keyboard return the animation and go out. I don't want it even start
to show.
The second way:
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWillShow:)
name:UIKeyboardWillShowNotification object:nil];
- (void)esconde {
for (UIWindow *keyboardWindow in [[UIApplication sharedApplication]
windows])
for (UIView *keyboard in [keyboardWindow subviews])
if([[keyboard description] hasPrefix:@UIPeripheralHostView]
== YES) [keyboard removeFromSuperview];
}
- (void)keyboardWillShow:(NSNotification *)aNotification {
[self performSelector:@selector(esconde) withObject:nil afterDelay:0];
}
Result: Well, work... But... It show the very start of the animation, but
the keyboard don't show. See that I NEED some delay, because this I use the
performSelector. I don't need more delay than the use of this way. If I use
the function directly, the UIPeripheralHostView will not exist. This way
is little dirty...
The problem to automatic focus a text box (it work) and than show the
keyboard isn't working.
How can I use the comand [keyboard showForFocusedTextBox]. Any more idea to
control the keyboard?
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Exporting and Importing CoreData
Hello, I need to create an export / import system for my app, and just thought that asking the list for some advices could help a lot. The CoreData database I have is fairly simple. No relationships, only 3 entities with no more than 4 properties each: numbers and strings. So I think exporting this as XML is the more appropriate solution. Also, it would allow users make changes in the file easily. Are there any serious drawbacks from using this method? Or may a better solution? What worries me most is the XML validation. It's not a high priority, but having an at least decent XML is worthwhile. The big question: A header saying XML version 1.0 is enough? Or do I need to create a DTD? Also, now on the mechanics, I think creating a mutable string and go appending parts of the XML in a loop is adequate for this task, and using NSXMLParser to parse it back should work. Indeed, the file will not be that big (usually a few hundreds of KBs, really extremes cases are 1 or 2MB). Well, at least I'm not aware of a framework to export / import CoreData, I don't even think it is possible. Any yes or no on my ideas are really appreciated. Thanks, Best wishes, Siegfried___ 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
Problem with setAttributesOfItemAtPath:error:
I'm writing an application that copies files from one folder to another. I've been using NSFileManager copyItemAtPath:toPath:error: and it generally works well. However, when trying to copy files from a local folder to a folder on a remote volume, copyItemAtPath:toPath:error: will sometimes fails to set the creation and modification dates of the item copied. The problem is that when it fails to set the attributes of the item it copies, it will not report it as an error (not sure if this is a bug, this is kind of very annoying). In any case, I wanted to dig a little deeper to find what's going on with that since I set permissions on the original folder to read/write for everyone and the receiving or destination folder on the remote drive with the same read/write permission to everybody. Of course, I connected with my user ID and password on the remote volume. When I check the permissions in the Finder, I see that both the source and destination folders have read/write permissions for the owner, the group and everybody. So, from there, I decided to systematically set the attributes myself, since copyItemAtPath:toPath:error: is failing to do it. So, I'm using attributesOfItemAtPath:error: and setAttributesOfItemAtPath:error to try to set the attributes of the copied item to that of the original item. I was not expecting it to really succeed but at least I was hoping to catch the error. That's where it gets interesting. When it fails, the localized description of the error is invariably You don’t have permission to save the file “Blah” in the folder “Folder Blah”. Folder Blah in this case is the destination folder on the remote drive. So, what am I missing here? The error is plain wrong in the first place because I was not attempting to copy the item, it's already copied! I just checked again Folder Blah permissions and they are still set to read/write to owner, group and everybody. Can someone explains this result? Thanks in advance! -Laurent. -- Laurent Daudelin AIM/iChat/Skype:LaurentDaudelin http://www.nemesys-soft.com/ Logiciels Nemesys Software laur...@nemesys-soft.com ___ 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
NSCollectionView and firstResponder madness
Hi everyone, I have an NSCollectionView in a sheet. The NSCV does not allow selection and is used for displaying a list (so maxNumberOfColumns = 1) of views. These views have things like NSComboBoxes and NSTextFields in them. I'm trying to figure out how to be able to tab from textfield to textfield, jumping in between collectionViewItems, if necessary. I've tried patching my NSCollectionViewItem subclass into the responder chain, overriding various NSResponder methods on various objects, and so on. All of this has been fruitless. I never see any of the events, let alone am able to respond to them. How should I go about tabbing between views in disparate NSCollectionViewItems? Thanks, Dave ___ 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: iPhone animation puzzle
Nothing was reversed, unfortunately. Block-based animation was introduced in
iOS 4.0, and user interaction has always been off by default during one, so if
you wanted user interaction you always had to use
UIViewAnimationOptionAllowUserInteraction - and you still do.
Apple did seem to regret this, and signaled an intent to change this policy;
but they have never done so, and indeed it is hard to see how they could do it
coherently.
(Of course, Apple can reverse anything at any time, like when they reversed the
meaning of the y-component of a shadow offset without warning and screwed up
everyone's drawing starting in 3.2.)
m.
On Sun, 20 Mar 2011 14:13:25 -0400, Jeff Kelley slauncha...@gmail.com said:
If I recall correctly, in iOS 4.0, this was reversed, but the next update
changed the behavior to what we have now.
On Mar 20, 2011, at 1:25 PM, WT wrote:
I seem to recall that one of the WWDC 2010 instructional videos - available
for free from Apple's developer site - mentions that the block version has
UIViewAnimationOptionAllowUserInteraction off by default.
That being said, have you filed a document enhancement request?
WT
On Mar 20, 2011, at 1:59 PM, David Rowland wrote:
That did it.
The View Programmming Guide for iOS, discusses both methods and implies
that their code samples are equivalent. They don't say, or I didn't see,
that the option you mention is on by default for the begin/commit style and
off for the newer block style.
thanks,
David
On Mar 19, 2011, at 5:08 PM, Roland King wrote:
UIViewAnimationOptionAllowUserInteraction ?
On Mar 20, 2011, at 5:42, David Rowland rowla...@sbcglobal.net wrote:
This works. It fades the label to invisibility.
label.alpha = 1.0;
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:2.5];
label.alpha = 0;
[UIView commitAnimations];
and so does this,
label.alpha = 1.0;
[UIView animateWithDuration:2.5 animations:^{label.alpha = 0.0;} ];
The documentation says the latter is now preferred and does the same
thing as the former. In particular, both will
start a separate thread for the animation.
My problem is that the second method seems to block the main thread.
While it is acting I cannot use any of the controls on the screen. The
first method lets me do what I wish as it proceeds.
Anyone have advice?
thanks,
David
Jeff Kelley
slauncha...@gmail.com
--
matt neuburg, phd = m...@tidbits.com, http://www.apeth.net/matt/
A fool + a tool + an autorelease pool = cool!
Programming iOS 4!
http://www.apeth.net/matt/default.html#iosbook___
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Re: TableView sorts and then it doesn't--SOLVED
Problem solved. The sort key for the decimal property was misspelled in the table column attributes in IB. On Mar 20, 2011, at 8:48 PM, Scott Anguish wrote: have you implemented the delegate methods? is the array mutable? or do you supply a new array that is sorted? do you reload the data? On Mar 20, 2011, at 8:44 PM, Lynn Barton wrote: I have a document based application. The document window has an NSTableView with six columns. Four columns are bound to four text properties of an entity in my model; one column is bound to a decimal property, and one column has check boxes bound to a boolean property. When I run the application and open the saved document I can sort the text columns and the check box column by clicking on their headers. But once I click on the decimal column header, not only does it not sort but none of the other columns will sort after that. What's going on here? ___ 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: Exporting and Importing CoreData
On Mar 23, 2011, at 8:13 PM, Siegfried wrote: Hello, I need to create an export / import system for my app, and just thought that asking the list for some advices could help a lot. The CoreData database I have is fairly simple. No relationships, only 3 entities with no more than 4 properties each: numbers and strings. So I think exporting this as XML is the more appropriate solution. Also, it would allow users make changes in the file easily. Are there any serious drawbacks from using this method? Or may a better solution? What worries me most is the XML validation. It's not a high priority, but having an at least decent XML is worthwhile. The big question: A header saying XML version 1.0 is enough? Or do I need to create a DTD? Also, now on the mechanics, I think creating a mutable string and go appending parts of the XML in a loop is adequate for this task, and using NSXMLParser to parse it back should work. Indeed, the file will not be that big (usually a few hundreds of KBs, really extremes cases are 1 or 2MB). Well, at least I'm not aware of a framework to export / import CoreData, I don't even think it is possible. Any yes or no on my ideas are really appreciated. Thanks, Best wishes, Siegfried How about using a property list file instead? Easier to import and export, and can be edited with tools such as Property List Editor, though your users might not know how to use it, or even have it. WT___ 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: Problem with setAttributesOfItemAtPath:error:
On Mar 23, 2011, at 6:17 PM, Laurent Daudelin wrote: I've been using NSFileManager copyItemAtPath:toPath:error: and it generally works well. However, when trying to copy files from a local folder to a folder on a remote volume, copyItemAtPath:toPath:error: will sometimes fails to set the creation and modification dates of the item copied. The problem is that when it fails to set the attributes of the item it copies, it will not report it as an error (not sure if this is a bug, this is kind of very annoying). In any case, I wanted to dig a little deeper to find what's going on with that since I set permissions on the original folder to read/write for everyone and the receiving or destination folder on the remote drive with the same read/write permission to everybody. Of course, I connected with my user ID and password on the remote volume. When I check the permissions in the Finder, I see that both the source and destination folders have read/write permissions for the owner, the group and everybody. So, from there, I decided to systematically set the attributes myself, since copyItemAtPath:toPath:error: is failing to do it. So, I'm using attributesOfItemAtPath:error: and setAttributesOfItemAtPath:error to try to set the attributes of the copied item to that of the original item. I was not expecting it to really succeed but at least I was hoping to catch the error. That's where it gets interesting. When it fails, the localized description of the error is invariably You don’t have permission to save the file “Blah” in the folder “Folder Blah”. Folder Blah in this case is the destination folder on the remote drive. So, what am I missing here? The error is plain wrong in the first place because I was not attempting to copy the item, it's already copied! I just checked again Folder Blah permissions and they are still set to read/write to owner, group and everybody. Can someone explains this result? Not all file system drivers support all attributes. Even if, on the file server, the local file system driver supports the attributes you're trying to set, the file sharing protocol may not. Even if the file sharing protocol does, the file system driver on the client machine that implements that protocol may not. You can see what happens when you drop down to using lower-level routines like setattrlist(). You can also use Apple's FSMegaInfo sample code to query the file system's capabilities using getattrlist(). (You can, of course, write your own tool to query that, but FSMegaInfo is ready-built.) Regards, Ken ___ 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: Exporting and Importing CoreData
On 23/03/2011, at 20:38, WT wrote: On Mar 23, 2011, at 8:13 PM, Siegfried wrote: Hello, I need to create an export / import system for my app, and just thought that asking the list for some advices could help a lot. … How about using a property list file instead? Easier to import and export, and can be edited with tools such as Property List Editor, though your users might not know how to use it, or even have it. WT I was considering using it initially, but as you've stated that would make things a bit more complicated when it comes to editing. XML would be ideal. Also, the final file would be less verbose (not filled with nested dicts and key value pairs). I really don't know when it comes to building the system. Do you think it would integrate with CoreData better? Or just mean less code to write? The latter case is not a problem though :-) Thanks WT!___ 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: Exporting and Importing CoreData
On Mar 23, 2011, at 8:46 PM, Siegfried wrote: On 23/03/2011, at 20:38, WT wrote: On Mar 23, 2011, at 8:13 PM, Siegfried wrote: Hello, I need to create an export / import system for my app, and just thought that asking the list for some advices could help a lot. … How about using a property list file instead? Easier to import and export, and can be edited with tools such as Property List Editor, though your users might not know how to use it, or even have it. WT I was considering using it initially, but as you've stated that would make things a bit more complicated when it comes to editing. XML would be ideal. Also, the final file would be less verbose (not filled with nested dicts and key value pairs). If you save your property list as XML and not as a binary file, then it's still XML and can be edited equally with PLE or any text editor (though maintaining its property list format may be a challenge for your users). As for how verbose it would be, a simple structure such as what you mentioned shouldn't produce anything overly verbose, I think. I suggest you try some simple tests to see how you like the results. I really don't know when it comes to building the system. Do you think it would integrate with CoreData better? Or just mean less code to write? The latter case is not a problem though :-) I'm not entirely sure because I'm relatively inexperienced with Core Data but I suspect that it would involve much less code than having to parse the input file yourself. Thanks WT! Most welcome. :) WT ___ 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: Exporting and Importing CoreData
On 24/03/2011, at 10:13 AM, Siegfried wrote: I need to create an export / import system for my app, and just thought that asking the list for some advices could help a lot. The CoreData database I have is fairly simple. No relationships, only 3 entities with no more than 4 properties each: numbers and strings. Have you considered using SQLite, either for the import/export file format, or even for the native app document format (so the native and export file are actually the same thing and no export is needed)? It removes several layers of complication. There are many tools for manipulating SQLite data on every platform, so it's easy to access the document elsewhere. Tom BareFeetWare -- Comparison of SQLite GUI tools: http://www.barefeetware.com/sqlite/compare/?ml ___ 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: Problem with setAttributesOfItemAtPath:error:
On Mar 23, 2011, at 16:38, Ken Thomases wrote: On Mar 23, 2011, at 6:17 PM, Laurent Daudelin wrote: I've been using NSFileManager copyItemAtPath:toPath:error: and it generally works well. However, when trying to copy files from a local folder to a folder on a remote volume, copyItemAtPath:toPath:error: will sometimes fails to set the creation and modification dates of the item copied. The problem is that when it fails to set the attributes of the item it copies, it will not report it as an error (not sure if this is a bug, this is kind of very annoying). In any case, I wanted to dig a little deeper to find what's going on with that since I set permissions on the original folder to read/write for everyone and the receiving or destination folder on the remote drive with the same read/write permission to everybody. Of course, I connected with my user ID and password on the remote volume. When I check the permissions in the Finder, I see that both the source and destination folders have read/write permissions for the owner, the group and everybody. So, from there, I decided to systematically set the attributes myself, since copyItemAtPath:toPath:error: is failing to do it. So, I'm using attributesOfItemAtPath:error: and setAttributesOfItemAtPath:error to try to set the attributes of the copied item to that of the original item. I was not expecting it to really succeed but at least I was hoping to catch the error. That's where it gets interesting. When it fails, the localized description of the error is invariably You don’t have permission to save the file “Blah” in the folder “Folder Blah”. Folder Blah in this case is the destination folder on the remote drive. So, what am I missing here? The error is plain wrong in the first place because I was not attempting to copy the item, it's already copied! I just checked again Folder Blah permissions and they are still set to read/write to owner, group and everybody. Can someone explains this result? Not all file system drivers support all attributes. Even if, on the file server, the local file system driver supports the attributes you're trying to set, the file sharing protocol may not. Even if the file sharing protocol does, the file system driver on the client machine that implements that protocol may not. You can see what happens when you drop down to using lower-level routines like setattrlist(). You can also use Apple's FSMegaInfo sample code to query the file system's capabilities using getattrlist(). (You can, of course, write your own tool to query that, but FSMegaInfo is ready-built.) Regards, Ken Hello Ken. I actually looked at FSMegaInfo but when I built it, I realized that it was using a lot of deprecated functions in 10.6 so I decided against using any part of it because of the amount of work that would be required to rewrite some parts of it. And yes, I do understand that different file systems will have different attributes. But, I'm sharing that remote volume from an Intel iMac running 10.5.8, connected to it through AFP. Shouldn't AFP supports basic file attributes? Not using Samba here or WebDAV, just plain Finder Shared computers... -Laurent. -- Laurent Daudelin AIM/iChat/Skype:LaurentDaudelin http://www.nemesys-soft.com/ Logiciels Nemesys Software laur...@nemesys-soft.com ___ 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: Exporting and Importing CoreData
On 23/03/2011, at 20:55, WT wrote: On Mar 23, 2011, at 8:46 PM, Siegfried wrote: On 23/03/2011, at 20:38, WT wrote: On Mar 23, 2011, at 8:13 PM, Siegfried wrote: Hello, I need to create an export / import system for my app, and just thought that asking the list for some advices could help a lot. … How about using a property list file instead? Easier to import and export, and can be edited with tools such as Property List Editor, though your users might not know how to use it, or even have it. WT I was considering using it initially, but as you've stated that would make things a bit more complicated when it comes to editing. XML would be ideal. Also, the final file would be less verbose (not filled with nested dicts and key value pairs). If you save your property list as XML and not as a binary file, then it's still XML and can be edited equally with PLE or any text editor (though maintaining its property list format may be a challenge for your users). As for how verbose it would be, a simple structure such as what you mentioned shouldn't produce anything overly verbose, I think. I suggest you try some simple tests to see how you like the results. I agree. Editing a XML plist is not difficult, and can be done with no problems in a standard text editor — users may not have problems. I'll be working on some tests as you suggested. I really don't know when it comes to building the system. Do you think it would integrate with CoreData better? Or just mean less code to write? The latter case is not a problem though :-) I'm not entirely sure because I'm relatively inexperienced with Core Data but I suspect that it would involve much less code than having to parse the input file yourself. Yes, parsing is the laborious part. I see calling a method on NSDictionary to read the plist is a lot easier :-) but now just tests may reveal the next path to take. At least, I'd get the validation stuff for free. Thanks again WT, Best regards, Sirgfried___ 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: Exporting and Importing CoreData
On 23/03/2011, at 20:57, BareFeetWare wrote: On 24/03/2011, at 10:13 AM, Siegfried wrote: I need to create an export / import system for my app, and just thought that asking the list for some advices could help a lot. The CoreData database I have is fairly simple. No relationships, only 3 entities with no more than 4 properties each: numbers and strings. Have you considered using SQLite, either for the import/export file format, or even for the native app document format (so the native and export file are actually the same thing and no export is needed)? It removes several layers of complication. Well, the app is not document based, so exporting its internal database is only for backup and sharing purposes. Also, I don't think exporting a partial database would be practical with SQLite (exporting one kind of entity for example). So I don't think that's something There are many tools for manipulating SQLite data on every platform, so it's easy to access the document elsewhere. Tom BareFeetWare -- Comparison of SQLite GUI tools: http://www.barefeetware.com/sqlite/compare/?ml Great link! Quite useful. Thanks Tom for providing valuable information, Best wishes, Siegfried___ 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: Problem with setAttributesOfItemAtPath:error:
On Mar 23, 2011, at 7:37 PM, Laurent Daudelin wrote: I actually looked at FSMegaInfo but when I built it, I realized that it was using a lot of deprecated functions in 10.6 so I decided against using any part of it because of the amount of work that would be required to rewrite some parts of it. First of all, deprecated doesn't mean not available. Second, the disk image I have (maybe from some time ago) has a pre-built binary. And yes, I do understand that different file systems will have different attributes. But, I'm sharing that remote volume from an Intel iMac running 10.5.8, connected to it through AFP. Shouldn't AFP supports basic file attributes? Depends on what you mean by basic. I don't recall you saying which attributes you were trying to set when you got errors. Regards, Ken ___ 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
Changed Properties
I love using CoreData and one of my favorite features is its ability to get me the changed values between commits without any work on my end. I know I can do it the old fashioned way of putting bools and setter methods that mark those booleans as dirty on changes, but I was curious if there was a good way to perhaps use CoreData mechanics or other Obj-C mechanics to do the same sort of thing in NSObject directly-derived classes. It seems to me that perhaps some KVO method might be useful for this purpose. ___ 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
Help with Custom Control
Hi, I built a special control with a custom view and several parts, including standard controls and some subviews. The thing does special displaying and animation, and needs to be connected to other parts of the UI and to the document controller. The set up works very nicely. Isolating it as a unit helped me debug minor drawing bugs and make its internal behaviour very consistent. However, I need to use several of these in the UI, so the whole wiring business involves dozens of connections in IB. Hence my questions: 1. Is there a way to make a custom NSView send IBActions as if it were one of the standard controls? 2. Is there a simple way to turn my little device into something I can add to the library and reuse in several places. The idea would be to treat it as aunit and be able to just wire an Action to the file's owner. 3. The way it is working right now is through a triple delegation - I need to have a mouse up event initiated in a subview of my custom view trigger an action in the enclosing view which is in turn forwarded to the controller. A, B and C are Custom Views A contains B, B contains C; B is C's delegate, A is B's delegate, File's Owner is A's delegate; Clicking C sends a message to F.O. It works, but I was wondering if the design is not too complicated? (I am trying to keep each part from having to know about other part's workings). I'd appreciate any ideas... ___ 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: Changed Properties
On Mar 23, 2011, at 20:08, Alex Kac wrote: I love using CoreData and one of my favorite features is its ability to get me the changed values between commits without any work on my end. I know I can do it the old fashioned way of putting bools and setter methods that mark those booleans as dirty on changes, but I was curious if there was a good way to perhaps use CoreData mechanics or other Obj-C mechanics to do the same sort of thing in NSObject directly-derived classes. It seems to me that perhaps some KVO method might be useful for this purpose. I'm pretty sure the answer is a pretty flat no. I can only think of 4 ways it could be done: 1. Write an advanced version of properties that does (basically) the bool/setter thing for you, with a new API. 2. Integrate the bool/setter thing into KVO. 3. Mimic the KVO approach of swizzling setter method implementations at run time, and maintain your change information that way. 4. Use KVO to observe every property of every object. #1 is actually feasible, though quite a tricky task. (The implementation is similar, I think, to parts of what various people have done for language bridges to Objective-C.) #2-4 all sound horrible. FWIW. ___ 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
