Bindings Question
I have an app that I'm making for practice that has a tableview, and a text field (and many other things, but the ones that are the problem are these two) I just successfully changed my app to use bindings. However, whenever I pressed a button before, something would be added into a NSMutableArray, and then the string would show up in the table view. Now, something IS added into the NSmutableArray, and will show up, but not the string. The thing that's added is just this blank. How do you solves these so that when I press the button, the string in the text field will actually be added and shown in the table view? Thanks! ___ 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 [EMAIL PROTECTED]
Bindings question...
I have a question regarding bindings: when I bind the value of a TableColumn to a controller, I specify the key path as something like this: @"arrangedObjects.name". So each row of the table, displays the "name" field from an object in the "arrangedObjects" property of the controller. In the IB it's actually broken into the controller key, "arrangedObjects", and the keypath, "name", though i don't see how this impacts the bind:toObject:withKeyPath:options: method. When I modify a value in a view, I send the setValue:forKey: message to the controller. What I don't understand is how the TableColumn is specifying the particular instance in the "arrangedObjects" array that was changed. If I just say this: [controller setValue:@"new value" forKey:@"arrangedObjects.name"] the specific instance is not specified. What is actually happening under the covers here? One possibility I can think of is that it uses the collection accessor pattern (objectInAtIndex:) to retrieve the object, then use the setValue:forKey: on the individual object. I'm trying to use bindings to link a custom view to NSManagedObject instances. The view uses cells to represent each element of the controller collection, in a fashion analogous to TableColumn. Thanks for any help. ___ 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
basic bindings question
Hi All, I'm trying to get my feet wet with bindings and want to try something simpler than the mail example provided online. All I'm trying to do is to replace the target-action-outlet approach with bindings in the simplest case I can think of: a text field whose value would correspond to an ivar in the controller. One text field would receive the number, a button would click, pass the number to the ivar, and redisplay that value in another text field. First off, is it possible possible to bind directly to an instance variable in the controller? In my hyper-basic example, I'm collapsing M and C. I thought doing so should be OK, so I tried: Bind to: Controller Model Key Path: self.number (number is the ivar) (self presumably being the controller) This didn't work. Unfortunately, I am also confused about the intended receiver for addObserver: forKeyPath:. I thought it would be the ivar (number), but I get a warning that NSNumber may not respond to that method (and sure enough the docs show that it doesn't). Logically, the second text field should "observe" that the model/controller ivar (number) has changed. But I thought you were not supposed to use outlets either. Does this mean you can only use bindings for arrays? Clearly that can't be right If anyone knows of a "hyper-simple" example dispensing with tables and arrays, I'd really appreciate the link Thanks. 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 [EMAIL PROTECTED]
Re: Bindings Question
Normally you would have the table controlled by a NSArrayController. You would bind the button to an action method which would take the value from the text field and pass it to addObject: method of the array controller. --- On Thu, 9/25/08, Eric Lee <[EMAIL PROTECTED]> wrote: > From: Eric Lee <[EMAIL PROTECTED]> > Subject: Bindings Question > To: Cocoa-dev@lists.apple.com > Date: Thursday, September 25, 2008, 5:34 PM > I have an app that I'm making for practice that has a > tableview, and a > text field (and many other things, but the ones that are > the problem > are these two) > > I just successfully changed my app to use bindings. > However, whenever > I pressed a button before, something would be added into a > > NSMutableArray, and then the string would show up in the > table view. > > Now, something IS added into the NSmutableArray, and will > show up, but > not the string. The thing that's added is just this > blank. > > How do you solves these so that when I press the button, > the string in > the text field will actually be added and shown in the > table view? > > Thanks! > ___ > > 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/idou747%40yahoo.com > > This email sent to [EMAIL PROTECTED] ___ 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 [EMAIL PROTECTED]
Re: Bindings Question
Sorry for the late response...computer froze Anyways, yeah, I have a NSArrayController, and I binded the table view to it, which let me actually add something. How do you bind a button to an action? Just control-drag? On Sep 25, 2008, at 7:39 PM, Chris Idou wrote: Normally you would have the table controlled by a NSArrayController. You would bind the button to an action method which would take the value from the text field and pass it to addObject: method of the array controller. --- On Thu, 9/25/08, Eric Lee <[EMAIL PROTECTED]> wrote: From: Eric Lee <[EMAIL PROTECTED]> Subject: Bindings Question To: Cocoa-dev@lists.apple.com Date: Thursday, September 25, 2008, 5:34 PM I have an app that I'm making for practice that has a tableview, and a text field (and many other things, but the ones that are the problem are these two) I just successfully changed my app to use bindings. However, whenever I pressed a button before, something would be added into a NSMutableArray, and then the string would show up in the table view. Now, something IS added into the NSmutableArray, and will show up, but not the string. The thing that's added is just this blank. How do you solves these so that when I press the button, the string in the text field will actually be added and shown in the table view? Thanks! ___ 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/idou747%40yahoo.com This email sent to [EMAIL PROTECTED] ___ 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/ericlee1994%40gmail.com This email sent to [EMAIL PROTECTED] ___ 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 [EMAIL PROTECTED]
Re: Bindings question...
On Dec 12, 2009, at 11:03, Jim Majure wrote:
> I have a question regarding bindings: when I bind the value of a TableColumn
> to a controller, I specify the key path as something like this:
> @"arrangedObjects.name". So each row of the table, displays the "name" field
> from an object in the "arrangedObjects" property of the controller. In the IB
> it's actually broken into the controller key, "arrangedObjects", and the
> keypath, "name", though i don't see how this impacts the
> bind:toObject:withKeyPath:options: method.
>
> When I modify a value in a view, I send the setValue:forKey: message to the
> controller. What I don't understand is how the TableColumn is specifying the
> particular instance in the "arrangedObjects" array that was changed. If I
> just say this:
>
> [controller setValue:@"new value" forKey:@"arrangedObjects.name"]
>
> the specific instance is not specified. What is actually happening under the
> covers here?
>
> One possibility I can think of is that it uses the collection accessor
> pattern (objectInAtIndex:) to retrieve the object, then use the
> setValue:forKey: on the individual object.
It's kind of mysterious, but I'm prepared to take some wild guesses hoping that
someone who knows more will jump in and correct/educate me.
There are a couple of pieces to consider:
1. While a table column represents an entire list of values, a NSTableColumn
really only represents a single value (via its single cell). It *appears* to
represent the entire list by representing different values at different times.
2. Bindings that we set in IB, such as NSTableColumn's "value" binding, are
what the documentation calls "Cocoa bindings", as opposed to just plain
"bindings". Presumably, all Cocoa bindings have the ability to recognize
certain predefined keys ("selection", "arrangedObjects", etc -- probably the
same list of keys that pops up at the controller key field in IB) as the first
component of the key path.
3. When sent to a NSArray, 'valueForKey:' returns an array of the values of the
key for each component element. [It's not clear whether NSTableColumn ever uses
this mechanism, though.]
4. When sent to a NSArray, 'setValue:forKey:' sets the value of each component
element to the same thing. [But it's unlikely this has any relevance to
NSTableColumn -- it's more relevant to changing multiple values displayed in
text fields, I think.]
So I suspect that NSTableColumn, via Cocoa bindings, decomposes the binding key
path into a reference to the NSArrayController and a model key, and effectively
does something like:
[[[controller valueForKey: @"arrangedObjects] objectAtIndex:
currentRow] setValue: newValue forKeyPath: @"name"];
It may do a similar thing for getting values, or it may make some use of #3
above. It must also (presumably) register as an observer of "arrangedObjects"
as well as the values of (some) individual objects, but it's not clear
precisely what the pattern of observers is.
Are you trying to bind Cocoa objects with Cocoa bindings, or do your objects
have a home-grown bindings implementation? If the latter, you might have a bit
of work to do, reinventing the Cocoa bindings behavior.
[I'll use this opportunity to get back on my soapbox and reiterate my opinion
that NSController and its demon offspring are truly horrible classes from the
developer's point of view. Their API behavior is no more and no less than
whatever behavior they happen to implement (in a properly designed class, the
implementation serves the API contract, not dominates it), and we're not told
what that behavior is, beyond a few vague generalities. We learn how to use
them by memorizing a few usage patterns that happen to work, and when we
overstep the bounds, things fail mysteriously, with at best a highly detailed
exception error message that is completely inscrutable.]
___
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: Bindings question...
On Dec 12, 2009, at 2:37 PM, Quincey Morris wrote:
> 2. Bindings that we set in IB, such as NSTableColumn's "value" binding, are
> what the documentation calls "Cocoa bindings", as opposed to just plain
> "bindings". Presumably, all Cocoa bindings have the ability to recognize
> certain predefined keys ("selection", "arrangedObjects", etc -- probably the
> same list of keys that pops up at the controller key field in IB) as the
> first component of the key path.
Some clarifications may be in order. As this is the Cocoa list, and there is no
other use of the term "binding" in Cocoa other than "Cocoa bindings", IMHO I
think it best to encourage every poster to only use the term "binding" (of any
conjugation) to refer to "Cocoa Bindings".
The "predefined keys" are not a function of bindings, they are simply
properties of the controller class(es). The list in IB just happens to be those
keys that the specific selected NSObjectController subclass implements. This is
a feature of IB, rather than any function of bindings per se. It will be
empty/disabled for any other class.
Best,
Keary Suska
Esoteritech, Inc.
"Demystifying technology for your home or business"
___
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: Bindings question...
On or about 12/12/09 12:02 PM, thus spake "cocoa-dev-requ...@lists.apple.com" : > Date: Sat, 12 Dec 2009 13:03:02 -0600 > From: Jim Majure > Subject: Bindings question... > > What I don't understand is how the TableColumn is > specifying the particular instance in the "arrangedObjects" array that > was changed. I find myself unable to make any sense of the question, but, thinking about what you could possibly mean, a couple of thoughts occur to me: (1) arrangedObjects is merely a presentation layer, as it were. Are you confusing arrangedObjects with content? (2) When thinking about what tables "automatically" do, are you taking into account the selection? m. -- matt neuburg, phd = m...@tidbits.com, http://www.tidbits.com/matt/ pantes anthropoi tou eidenai oregontai phusei Among the 2007 MacTech Top 25, http://tinyurl.com/2rh4pf AppleScript: the Definitive Guide, 2nd edition http://www.tidbits.com/matt/default.html#applescriptthings Take Control of Exploring & Customizing Snow Leopard http://tinyurl.com/kufyy8 RubyFrontier! http://www.apeth.com/RubyFrontierDocs/default.html TidBITS, Mac news and reviews since 1990, http://www.tidbits.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: basic bindings question
On May 14, 2008, at 2:08 PM, Daniel Child wrote:
All I'm trying to do is to replace the target-action-outlet
approach with bindings in the simplest case I can think of: a text
field whose value would correspond to an ivar in the controller.
One text field would receive the number, a button would click, pass
the number to the ivar, and redisplay that value in another text
field.
Actually, requiring the button click to perform the transfer is going
to make it harder. It will be easier to just have the field directly
update the ivar when editing completes.
First off, is it possible possible to bind directly to an instance
variable in the controller? In my hyper-basic example, I'm
collapsing M and C. I thought doing so should be OK, so I tried:
Bind to: Controller
Model Key Path: self.number (number is the ivar) (self presumably
being the controller)
This didn't work.
Leave out the "self.". Just use "number".
Unfortunately, I am also confused about the intended receiver for
addObserver: forKeyPath:. I thought it would be the ivar (number),
but I get a warning that NSNumber may not respond to that method
(and sure enough the docs show that it doesn't). Logically, the
second text field should "observe" that the model/controller ivar
(number) has changed. But I thought you were not supposed to use
outlets either.
There are two common misconceptions here:
1) KVO is not for observing properties, as such. It's for observing
the object which _has_ the property. To put it another way: I don't
observe the number, I observe the controller for changes in its
number property.
2) A property is _not_ the ivar. The ivar, if it exists at all, is
an implementation detail of how the class implements the property. A
property is part of the interface of the object. You will find it
much easier if you conceptualize a property as the set of KVC-
conforming methods in the object's interface. A "key" is a string
naming or identifying a property. (Yes, KVC and KVO provide built-in
support for properties which don't have accessor methods. They will
access the ivar directly. However, this is just a convenience and a
fall-back position. It doesn't materially change how you should
conceptualize properties.)
To illustrate:
@interface Foo : NSObject
{
NSNumber* number; // <-- This is NOT the property
}
// _These_ are the property:
- (NSNumber*) number;
- (void) setNumber:(NSNumber*)newNumber;
@end
// ... in some other code somewhere
Foo* myFoo = /* ... */
[myFoo addObserver:self forKeyPath:@"number"];
This object (self) is observing the myFoo object for changes in its
"number" property.
Think also about the KVO notifications you will receive:
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)
object change:(NSDictionary *)change context:(void *)context;
Think about what you will be receiving in the "object" parameter of
that. You're not interested in knowing that some anonymous, free-
floating NSNumber object has changed; you need to be informed which
object has had its "number" property changed. So, in this case, it
would be the Foo object which was myFoo in the above snippet. That's
why you need to conceptualize KVO as observing the object which has
the property, not as observing the property (or ivar) itself.
Consider the possibility that I use a plain "int" instead of an
NSNumber as the backing store for the number property of a Foo.
Surely, the "object" parameter of the observeValueForKeyPath...
method can't be that int, because an int isn't an object.
Furthermore, consider if there is _no_ backing storage for the number
property of a Foo. What if I changed the above @interface to omit
the "number" ivar. Foo still has a "number" property. Its meaning/
value is whatever results from the semantics of the two methods -
number and -setNumber:. In theory, they could compute the value on
the fly, call some library API, or even query a remote server to
determine the value. They could do anything and it need not involve
an ivar of any sort.
Lastly, I want to address a confusion that I've seen at other times
on this list (but which you didn't express). Often people have a
class with an NSMutableArray ivar, and they get confused as to why
modifications that they make directly to that ivar (as by -
addObject:, for example) don't result in KVO notifications and
updates to the bound GUI elements. The reason is that nothing is
observing that array. They are observing the owning object for
changes of the property for which that ivar is backing storage.
The array does not (and can not) send out KVO notifications. For one
thing, it doesn't know what object owns it nor what property it
represents. The owning object is what sends out the KVO
notifications. In order for it to do that, the owning object must be
messaged. It might be messaged with a KV
Re: basic bindings question
I think I understood the first half of what you said, and can now see
why making number the receiver of addObserver was totally wrong.
But I seem to have a problem.
If I want to observe the property of an object, and in my case, it
turns out that the M and C are collapsed into a model-controller, then
it's basically a case of asking something to observe itself. In other
words, your "myFoo addObserver: self forKeyPath:
@"number" becomes
- (void) awakeFromNib {
[self addOberver: self forKeyPath: @"number" options: 0 context: NULL];
}
I tried that and got the same message as before ( may not
respond to addObserver), only this time the receiver is the controller
instead of number.
Is it not possible to collapse M and C for a case where you want to
track a simple text field. It seems it must be.
On May 14, 2008, at 5:11 PM, Ken Thomases wrote:
To illustrate:
@interface Foo : NSObject
{
NSNumber* number; // <-- This is NOT the property
}
// _These_ are the property:
- (NSNumber*) number;
- (void) setNumber:(NSNumber*)newNumber;
@end
// ... in some other code somewhere
Foo* myFoo = /* ... */
[myFoo addObserver:self forKeyPath:@"number"];
This object (self) is observing the myFoo object for changes in its
"number" property.
Think also about the KVO notifications you will receive:
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:
(id)object change:(NSDictionary *)change context:(void *)context;
___
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 [EMAIL PROTECTED]
Re: basic bindings question
On May 14, 2008, at 10:54 PM, Daniel Child wrote:
If I want to observe the property of an object, and in my case, it
turns out that the M and C are collapsed into a model-controller,
then it's basically a case of asking something to observe itself.
Well, it is sometimes desirable for an object to observe itself for
changes to its properties. However, it is often not necessary. In
particular, an object's properties should only be modified by
messaging the object, which gives you a perfect way to "notice" that
the change is being made -- right in the method which is invoked by
the message.
For example, if your controller's number property is being changed,
then something should be invoking its -setNumber: method. In that
case, you can just add your code for coping with a change to that
method:
- (void) setNumber:(NSNumber*)newNumber
{
if (newNumber != number && ![number isEqualToNumber:newNumber])
{
[number release];
number = [newNumber retain];
// Add code to cope with a change in the number property here
}
}
Can you be more specific about why you want your controller to
observe its own number property? What are you trying to accomplish?
I suspect there's another way to accomplish what you're interested in.
In other words, your "myFoo addObserver: self
forKeyPath: @"number" becomes
- (void) awakeFromNib {
[self addOberver: self forKeyPath: @"number" options: 0 context:
NULL];
There's a typo there. You've missed the "s" in "addObserver".
}
I tried that and got the same message as before ( may not
respond to addObserver), only this time the receiver is the
controller instead of number.
Can you report the exact message you're getting? Is it a compile-
time warning or a run-time exception?
Is it not possible to collapse M and C for a case where you want to
track a simple text field. It seems it must be.
It is possible. We'll have to see what's going wrong in your
particular case.
Cheers,
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 [EMAIL PROTECTED]
Re: basic bindings question
On May 15, 2008, at 12:09 AM, Ken Thomases wrote:
Can you be more specific about why you want your controller to
observe its own number property? What are you trying to
accomplish? I suspect there's another way to accomplish what you're
interested in.
I'm simply trying to reduce bindings to the most basic case: type into
a text field, have that value observed, and then reflect it somewhere
else (as in another text field). The actual application I have in mind
uses text fields to enable the user to specify sort fields, and rather
than have a bunch of methods to check those values prior to sorting, I
thought I could use bindings to automatically have those values set as
soon as the user types them in. (I've used textDidChange in the past
to accomplish something similar, but I thought this would be an easy
case to try bindings. Especially since I might want to provide a more
elegant interface for specifying sort fields prior to the sort.
In other words, your "myFoo addObserver: self
forKeyPath: @"number" becomes
- (void) awakeFromNib {
[self addOberver: self forKeyPath: @"number" options: 0 context:
NULL];
There's a typo there. You've missed the "s" in "addObserver".
Oops. Sorry about that, but I get a runtime error all the same:
[ valueForUndefinedKey:]: this class is not
key value coding-compliant for the key values.
2008-05-15 00:32:19.909 StringBinding[564:10b] *** Terminating app due
to uncaught exception 'NSUnknownKeyException', reason:
'[ valueForUndefinedKey:]: this class is not
key value coding-compliant for the key values.'
Thanks!
___
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 [EMAIL PROTECTED]
Re: basic bindings question
On May 14, 2008, at 11:43 PM, Daniel Child wrote:
On May 15, 2008, at 12:09 AM, Ken Thomases wrote:
Can you be more specific about why you want your controller to
observe its own number property? What are you trying to
accomplish? I suspect there's another way to accomplish what
you're interested in.
I'm simply trying to reduce bindings to the most basic case: type
into a text field, have that value observed, and then reflect it
somewhere else (as in another text field). The actual application I
have in mind uses text fields to enable the user to specify sort
fields, and rather than have a bunch of methods to check those
values prior to sorting, I thought I could use bindings to
automatically have those values set as soon as the user types them
in. (I've used textDidChange in the past to accomplish something
similar, but I thought this would be an easy case to try bindings.
Especially since I might want to provide a more elegant interface
for specifying sort fields prior to the sort.
First, bindings are implemented using KVO, but KVO is not the same as
bindings.
Second, to do what you're talking about, you'd bind the text field's
value binding to the controller-model. There's no reason to have the
controller observe its own property in this scenario.
Third, while you can definitely set bindings up in code, that's not
"reduc[ing] bindings to the most basic case". Setting the binding up
via IB is the most basic case.
In other words, your "myFoo addObserver: self
forKeyPath: @"number" becomes
- (void) awakeFromNib {
[self addOberver: self forKeyPath: @"number" options: 0 context:
NULL];
There's a typo there. You've missed the "s" in "addObserver".
Oops. Sorry about that, but I get a runtime error all the same:
[ valueForUndefinedKey:]: this class is not
key value coding-compliant for the key values.
2008-05-15 00:32:19.909 StringBinding[564:10b] *** Terminating app
due to uncaught exception 'NSUnknownKeyException', reason:
'[ valueForUndefinedKey:]: this class is
not key value coding-compliant for the key values.'
This seems to have nothing to do with the above code. First, the key
involved is called "values" not "number". Second, the receiver is
the NSApplication instance. So, why is something trying to access a
non-existent "values" property of the NSApplication class?
NSUserDefaultsController has a "values" property. I wonder if you
temporarily had a binding to that which you attempted to redirect
toward File's Owner but you didn't change it properly.
-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 [EMAIL PROTECTED]
Re: basic bindings question
You were right, it accidentally switched to user defaults. Removing that and setting it back to controller still leads to a runtime exception. 2008-05-15 22:30:53.718 StringBinding[290:10b] An uncaught exception was raised 2008-05-15 22:30:53.719 StringBinding[290:10b] [0x119650> valueForUndefinedKey:]: this class is not key value coding- compliant for the key values. 2008-05-15 22:30:53.723 StringBinding[290:10b] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[ valueForUndefinedKey:]: this class is not key value coding-compliant for the key values.' 2008-05-15 22:30:53.723 StringBinding[290:10b] Stack: ( 2449281611, 2445869307, 2449280369, Under bindings, "Values" shows that it is set to Controller.number. I have set up conventional accessors. Under setNumber: I also try to bounce the value back to an outlet text field using [valueField setStringValue: [self number] stringValue]; But it doesn't even run. I am not clear why it is claiming NSApp is not key value coding-compliant when I set up the binding to the controller object. On May 15, 2008, at 12:54 AM, Ken Thomases wrote: This seems to have nothing to do with the above code. First, the key involved is called "values" not "number". Second, the receiver is the NSApplication instance. So, why is something trying to access a non-existent "values" property of the NSApplication class? NSUserDefaultsController has a "values" property. I wonder if you temporarily had a binding to that which you attempted to redirect toward File's Owner but you didn't change it properly. ___ 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 [EMAIL PROTECTED]
Re: basic bindings question
You misunderstood what I was saying. On May 15, 2008, at 9:47 PM, Daniel Child wrote: You were right, it accidentally switched to user defaults. Removing that and setting it back to controller still leads to a runtime exception. 2008-05-15 22:30:53.718 StringBinding[290:10b] An uncaught exception was raised 2008-05-15 22:30:53.719 StringBinding[290:10b] [0x119650> valueForUndefinedKey:]: this class is not key value coding- compliant for the key values. The above error says that something is trying to use KVC to access a property called "values" on an NSApplication instance. The NSApplication class does not provide such a property. I suspect you have a binding somewhere in your main nib (typically MainMenu.nib) where the controller is File's Owner (which is the NSApplication instance for this nib) and the model key path is "values" (or starts with "values."). This can happen accidentally if you at some point had a binding to the Shared User Defaults Controller and you later changed the controller for that binding without properly adjusting the key paths. 2008-05-15 22:30:53.723 StringBinding[290:10b] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[ valueForUndefinedKey:]: this class is not key value coding-compliant for the key values.' 2008-05-15 22:30:53.723 StringBinding[290:10b] Stack: ( 2449281611, 2445869307, 2449280369, Under bindings, "Values" shows that it is set to Controller.number. Please be more precise. At what GUI element's bindings are you looking? Off-hand, I can't think of any class which exposes a binding called "Values" plural. Many expose a binding called "Value" singular. Note though, that the above error is not referring the name of the binding, it's referring to the name of a key. I suspect you're focused on one particular binding, and assuming the error is happening because of that, while it's really due to some other binding that you're not paying attention to. I have set up conventional accessors. Under setNumber: I also try to bounce the value back to an outlet text field using [valueField setStringValue: [self number] stringValue]; You can do that, but you're missing the point of bindings. Why isn't the text field just bound to the same model property, so it automatically reflects any changes to that property? Have you read through the Cocoa Bindings Programming guide? It has a walkthrough of just such a simple bindings example as you're trying to reproduce. But it doesn't even run. I am not clear why it is claiming NSApp is not key value coding-compliant when I set up the binding to the controller object. As I say, I think you've got a form of tunnel vision that's common when developing. You're certain that the problem is happening in the part of the nib where you're focused, so you're not looking elsewhere. Take a step back and see if it's not in a different part of the nib, or possibly somewhere in your code. Try viewing the nib in list mode. Use Command-A to select all, and then Option-right-arrow to show every single object within it. Then, call up the bindings inspector (Command-4) and use the arrow keys to select each object in the nib in turn. Eventually, you'll find the object with the incorrect binding. (Prior to IB 3 there was a much easier way to find all connections among objects. I submitted a bug about the loss of usability, and Apple acknowledged it, but they haven't corrected it yet.) -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 [EMAIL PROTECTED]
Seemingly Simple Bindings Question
I have an NSPopUpButton with five menu items: WTD, MTD, QTD, YTD, and
Specific Dates. What I want to do is show and hide two labels and
textfields for Start Date and End Date depending on if the Specific
Dates option is selected.
My first attempt was to do
@property (readonly) BOOL specifyingDateRange;
-(BOOL)specifyingDateRange{
if([dateRangePopUp indexOfSelectedItem] == 4){
return YES;
}
return NO;
}
but this is not working correctly.
Can anyone explain what the correct implementation is and possibly
what mistake I made in assessing the problem?
Thanks in advance,
Jamie
___
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 [EMAIL PROTECTED]
Very basic Bindings question
Hi,
I am trying to use bindings for the first time. So this is a pretty basic
question.
As an example what i am trying to do is that i have a NSTextField in which user
enters some numeric value. I have a int type variable in my class that is
binded to the value field of this text field. I get the value in the variable
correctly. But the problem is that the accessor method that i have written are
not called. If i print something in the accessor methods, it is not printed on
the console.
Here is the code.
I have declared in myClass.h
@interface myClass: NSObject {
int Var;
}
-(void)setVar:(int)aNumber;
-(int)getVar;
In the myClass.m i have
@implementation myClass
-(void)setVar:(int)aNumber {
Var = aNumber;
}
-(int)getVar
{
return Var;
}
Why are these functions not being called ? Am i missing something in the
syntax or is it something else.
Thanx
___
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 [EMAIL PROTECTED]
NSValueTransformer/Cocoa Bindings question
I'm having trouble using an NSValueTransformer. Suppose I have an NSArrayController foo. If I bind a label's value to selection.number (which is an NSNumber) on foo, then this is fine. However, I'm having trouble when it comes to transforming this value. Suppose I have a second NSArrayController bar, whose content array binding is set to selection.number on foo, but with an NSValueTransformer transforming it into an NSArray. However, once I try to test this out, I get a crash, with this: *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[ valueForUndefinedKey:]: this class is not key value coding-compliant for the key number.' Two perplexing this come to mind: the only NSTableView I have is for a table whose columns are bound to foo (arrangedObjects.number), which works normally without the binding on bar. Second, I fail to see why the binding on bar fails when the binding on the label works. The only thing I can think of is that there is an array key expected where only a single key was given. Why is this, and how can I solve this? ___ 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
NSSearchField and bindings question
I'm going the Zarra book, "Core Data" and I;ve reached the section where an NSSearchfield is bound to one of the arrays used in the sample application (page 43). As instructed in the book, I configured the NSSearchfield's predicate binding as follows: Controller Key: filterPredicate Model Key Path: name Display Name: predicate Predicate Format: keyPath contains $value This did not work and the NSTableView (column) which should update itself from the NSArrayController does nothing. I found an example of this sort of thing here: http://homepage.mac.com/mmalc/CocoaExamples/controllers.html and found that the binding in the second predicate used for the NSSearchfield is configured like this: Controller Key: filterPredicate Model Key Path : Display Name: Last Name Predicate Format: lastName contains[cd] $value I configured my predicate binding fashion and it works. So my question is: Did I miss something in the book, or is the book wrong? Thanks ___ 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: Seemingly Simple Bindings Question
On 1 Sep 2008, at 9:38 am, Jamie Phelps wrote:
I have an NSPopUpButton with five menu items: WTD, MTD, QTD, YTD,
and Specific Dates. What I want to do is show and hide two labels
and textfields for Start Date and End Date depending on if the
Specific Dates option is selected.
My first attempt was to do
@property (readonly) BOOL specifyingDateRange;
-(BOOL)specifyingDateRange{
if([dateRangePopUp indexOfSelectedItem] == 4){
return YES;
}
return NO;
}
but this is not working correctly.
Can anyone explain what the correct implementation is and possibly
what mistake I made in assessing the problem?
You probably don't want to tie the functionality to a specific item
index - it makes it hard to easily change the UI without breaking (or
needing to revise) the code. Instead, you could use a tag value to
represent the item's function, or possibly its representedObject.
Not being familiar with bindings, I can't be sure how this relates to
that, but more conventionally you'd set an action and target for your
pop-up menu and the action's signature would look like:
- (IBAction)respondToDateRangePopUp:(id) sender
{
if([sender tag] == kTheTagImLookingFor)
[self doSomething];
}
hth,
Graham
___
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 [EMAIL PROTECTED]
Re: Seemingly Simple Bindings Question
On Aug 31, 2008, at 6:38 PM, Jamie Phelps wrote:
I have an NSPopUpButton with five menu items: WTD, MTD, QTD, YTD,
and Specific Dates. What I want to do is show and hide two labels
and textfields for Start Date and End Date depending on if the
Specific Dates option is selected.
My first attempt was to do
@property (readonly) BOOL specifyingDateRange;
-(BOOL)specifyingDateRange{
if([dateRangePopUp indexOfSelectedItem] == 4){
return YES;
}
return NO;
}
but this is not working correctly.
Can anyone explain what the correct implementation is and possibly
what mistake I made in assessing the problem?
It's hard to know without more details.
My suspicion is that you haven't arranged for any KVO change
notification to be sent out when this property changes its value. KVO
and Bindings do not poll the properties of objects to check if they've
changed. There has to be an affirmative notification sent out to
observers telling them that the property may have changed. That
notification is triggered by a message to the object which has the
property -- either a KVO-compliant setter (preferred) or a pair of
willChange…/didChange… messages (last resort if your design
absolutely can't conform to the normal way of doing things).
I assume the above method is in your controller. It certainly
shouldn't be in the model. However, is the mode implied by the pop-up
expressed in the model? And is the pop-up's selection bound through
the controller to that model property? If so, then I'd recode that
method to depend on the model property instead of the pop-up view's
state. And then I'd use a
+keyPathsForValuesAffectingSpecifyingDateRange method to inform KVO
that when the model property changes, that implies a change in the
specifyingDateRange property of the controller.
If somehow the mode implied by the pop-up isn't a model property, then
I'd make it a controller property. You'd still bind the pop-up's
selection to it, and you'd still use
+keyPathsForValuesAffectingSpecifyingDateRange to inform the KVO
system that the two properties are interrelated.
Cheers,
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 [EMAIL PROTECTED]
Re: Very basic Bindings question
On Sep 24, 2008, at 04:21 , Adil Saleem wrote:
Hi,
I am trying to use bindings for the first time. So this is a pretty
basic question.
As an example what i am trying to do is that i have a NSTextField in
which user enters some numeric value. I have a int type variable in
my class that is binded to the value field of this text field. I get
the value in the variable correctly. But the problem is that the
accessor method that i have written are not called. If i print
something in the accessor methods, it is not printed on the console.
Here is the code.
I have declared in myClass.h
@interface myClass: NSObject {
int Var;
}
-(void)setVar:(int)aNumber;
-(int)getVar;
Don't use getVar (also, don't start a variable with a capital
letter)... the correct naming convention is this:
@interface MyClass : NSObject { // the convention is to start class
names with a capital letter
int var;
}
-(void)setVar:(int)aNumber; // the setter message should be the word
set + [capital first letter] + rest of variable name
-(int)var; // the getter message should have the same name as
the variable
HTH, Jason
smime.p7s
Description: S/MIME cryptographic signature
___
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 [EMAIL PROTECTED]
Re: Very basic Bindings question
Hi,
here is how accessors should be defined. Watch the case too.
file:///Developer/Documentation/DocSets/com.apple.ADC_Reference_Library.CoreReference.docset/Contents/Resources/Documents/documentation/Cocoa/Conceptual/KeyValueCoding/Concepts/Compliant.html
HTH
Raphael
On Wed, Sep 24, 2008 at 10:21 AM, Adil Saleem <[EMAIL PROTECTED]>wrote:
> Hi,
>
> I am trying to use bindings for the first time. So this is a pretty basic
> question.
>
> As an example what i am trying to do is that i have a NSTextField in which
> user enters some numeric value. I have a int type variable in my class
> that is binded to the value field of this text field. I get the value in the
> variable correctly. But the problem is that the accessor method that i have
> written are not called. If i print something in the accessor methods, it is
> not printed on the console.
>
> Here is the code.
>
>
> I have declared in myClass.h
>
> @interface myClass: NSObject {
>
> int Var;
> }
>
> -(void)setVar:(int)aNumber;
> -(int)getVar;
>
> In the myClass.m i have
>
> @implementation myClass
>
> -(void)setVar:(int)aNumber {
>
>Var = aNumber;
> }
>
> -(int)getVar
> {
> return Var;
> }
>
>
> Why are these functions not being called ? Am i missing something in the
> syntax or is it something else.
>
>
> Thanx
>
>
>
>
>
>
> ___
>
> 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/raphael.sebbe%40gmail.com
>
> This email sent to [EMAIL PROTECTED]
>
___
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 [EMAIL PROTECTED]
Re: Re: NSSearchField and bindings question
On Jan 4, 2010 5:15pm, Saurabh Sharan wrote: You're not alone -- happened to me too. Though, when I downloaded the code from pragprog.com, it worked. - Saurabh On Sun, Jan 3, 2010 at 10:11 PM, lorenzo7...@gmail.com> wrote: I'm going the Zarra book, "Core Data" and I;ve reached the section where an NSSearchfield is bound to one of the arrays used in the sample application (page 43). As instructed in the book, I configured the NSSearchfield's predicate binding as follows: Controller Key: filterPredicate Model Key Path: name Display Name: predicate Predicate Format: keyPath contains $value This did not work and the NSTableView (column) which should update itself from the NSArrayController does nothing. I found an example of this sort of thing here: http://homepage.mac.com/mmalc/CocoaExamples/controllers.html and found that the binding in the second predicate used for the NSSearchfield is configured like this: Controller Key: filterPredicate Model Key Path : Display Name: Last Name Predicate Format: lastName contains[cd] $value I configured my predicate binding fashion and it works. So my question is: Did I miss something in the book, or is the book wrong? Thanks ___ 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/saurabh.sharan%40isharan.com This email sent to saurabh.sha...@isharan.com Thanks for the reply. The downloadable code differs from the book as well: Controller Key: filterPredicate Model Key Path: Display Name: Recipe Name <--- Here is one difference, book uses 'predicate' Predicate Format: name contains[c] $value <--- Here is another, book uses 'keyPath contains $value' This works. So, if not anything else, I know of two ways to do this now. Thanks again. ___ 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
To-Many/To-Many Master/Detail Core Data / Bindings Question
Howdy, Trying to crank out a real Cocoa app as an experiment - usually spend my time doing Cocoa Touch. Anyway, I have a pretty simple set of models: Accounts<->>Items I want to setup a screen with a table of accounts. When you click on an account, you see a table of items, click on an item, see it's detail. Simple. My question is if I can do this all with bindings. The table of accounts works fine. What I can't seem to figure out is how to limit the 'Items' in the second NSTableView to just be the ones associated with the selected account, using bindings. Is there a way to do so? I see I can set a fetch predicate for the NSArrayController that is controlling the items but I'm not sure how to reference the selected account in the 'account' table view to limit the contents of the second NSTableView - if that's even possible... Or alternatively, just have the items NSTableView show entities that are in the 'items' relationship of the selected account. Seems like a pretty simple use case but I'm missing the magic. I can see a path by subclassing NSArrayController but I was hoping to do it all with bindings if I could - I just don't know enough to know which way to go or if I should just break out the code. Any help appreciated. Cheers, Hunter___ 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: To-Many/To-Many Master/Detail Core Data / Bindings Question
On Dec 28, 2009, at 15:32, Hunter Hillegas wrote: > My question is if I can do this all with bindings. The table of accounts > works fine. What I can't seem to figure out is how to limit the 'Items' in > the second NSTableView to just be the ones associated with the selected > account, using bindings. If I understand your question correctly, the usual way is to bind the detail NSArrayController's content via the master NSArrayController's "selection" property. See: http://developer.apple.com/mac/library/documentation/Cocoa/Conceptual/CocoaBindings/Tasks/masterdetail.html ___ 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: To-Many/To-Many Master/Detail Core Data / Bindings Question
Hi Quincey, I did read this page - but I'm not sure it does what I want because it's only 2/3rds of my interface. The master-detail explained there works fine for my items list and to display the selected item's properties but I need the list of items (the master in Apple's example) to be the result of another relationship (the accounts - each account can have zero to many items). So almost as master-master-detail, even though that's a terrible term. Does that make more sense? On Dec 28, 2009, at 4:14 PM, Quincey Morris wrote: > On Dec 28, 2009, at 15:32, Hunter Hillegas wrote: > >> My question is if I can do this all with bindings. The table of accounts >> works fine. What I can't seem to figure out is how to limit the 'Items' in >> the second NSTableView to just be the ones associated with the selected >> account, using bindings. > > If I understand your question correctly, the usual way is to bind the detail > NSArrayController's content via the master NSArrayController's "selection" > property. See: > > > http://developer.apple.com/mac/library/documentation/Cocoa/Conceptual/CocoaBindings/Tasks/masterdetail.html > > > ___ > > 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/lists%40lastonepicked.com > > This email sent to li...@lastonepicked.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: To-Many/To-Many Master/Detail Core Data / Bindings Question
On Dec 28, 2009, at 16:19, Hunter Hillegas wrote: > I did read this page - but I'm not sure it does what I want because it's only > 2/3rds of my interface. The master-detail explained there works fine for my > items list and to display the selected item's properties but I need the list > of items (the master in Apple's example) to be the result of another > relationship (the accounts - each account can have zero to many items). So > almost as master-master-detail, even though that's a terrible term. Actually, your items are the *detail* for the account, and then possibly the master for another detail interface. So, let's say you have a NSTableView listing accounts, a second NSTableView listing items in the accounts list's selection, and a set of text fields, etc showing more details of the item(s) selected in the item list. The accounts list uses a NSArrayController whose content is bound to the accounts (array if not Core Data, set if Core Data) in your data model. Columns in your accounts list would be bound to accountsController.arrangedObjects.whateverAccountProperty. The items list uses a second NSArrayController whose content is bound to accountsController.selection.items. This represents the items in the selected account, or possibly in the selected accounts. (In NSControllerland, there's really no distinction between a single object or multiple objects, until later in the process -- each eventual UI element deals with the problem of how to display multiple items. There's also an option somewhere that controls how the items are merged if there are multiple selected accounts, but if your items are unique to an account, the result would be the same.) Columns in your items list would be bound to itemsController.arrangedObjects.whateverItemProperty. Item detail elements like text fields -- if you want them -- would be bound to itemsController.selection.whateverItemProperty. Such user interface elements would then display the value of the item selected in the items list. If there are multiple items selected, then the binding options for multiple values selections kick in. So your interface is not so much master-master-detail as dual-level master-detail. There's probably an alternative way of approaching this, by programmatically maintaining a fetch request for the items array controller, based on monitoring the selection of the account array controller, but I can't think of any obvious way to do this without writing code. (A few lines of code, but code nevertheless.) Chaining array controllers, and using the arrangedObjects or selection properties as appropriate, should allow you to design the interface codelessly. Does that sound like what you need? There was a different tutorial that explored some of this, but I can't find it any more. ___ 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: To-Many/To-Many Master/Detail Core Data / Bindings Question
Yes, that's exactly it. Dual level master detail. For whatever reason, the part I just couldn't see in my head was how to wire up the second NSArrayController to accountsController.selection.items. Thank you so much - just needed that little kick to get to the next step. Appreciate it. On Dec 28, 2009, at 7:38 PM, Quincey Morris wrote: > On Dec 28, 2009, at 16:19, Hunter Hillegas wrote: > >> I did read this page - but I'm not sure it does what I want because it's >> only 2/3rds of my interface. The master-detail explained there works fine >> for my items list and to display the selected item's properties but I need >> the list of items (the master in Apple's example) to be the result of >> another relationship (the accounts - each account can have zero to many >> items). So almost as master-master-detail, even though that's a terrible >> term. > > Actually, your items are the *detail* for the account, and then possibly the > master for another detail interface. > > So, let's say you have a NSTableView listing accounts, a second NSTableView > listing items in the accounts list's selection, and a set of text fields, etc > showing more details of the item(s) selected in the item list. > > The accounts list uses a NSArrayController whose content is bound to the > accounts (array if not Core Data, set if Core Data) in your data model. > > Columns in your accounts list would be bound to > accountsController.arrangedObjects.whateverAccountProperty. > > The items list uses a second NSArrayController whose content is bound to > accountsController.selection.items. This represents the items in the selected > account, or possibly in the selected accounts. (In NSControllerland, there's > really no distinction between a single object or multiple objects, until > later in the process -- each eventual UI element deals with the problem of > how to display multiple items. There's also an option somewhere that controls > how the items are merged if there are multiple selected accounts, but if your > items are unique to an account, the result would be the same.) > > Columns in your items list would be bound to > itemsController.arrangedObjects.whateverItemProperty. > > Item detail elements like text fields -- if you want them -- would be bound > to itemsController.selection.whateverItemProperty. Such user interface > elements would then display the value of the item selected in the items list. > If there are multiple items selected, then the binding options for multiple > values selections kick in. > > So your interface is not so much master-master-detail as dual-level > master-detail. > > There's probably an alternative way of approaching this, by programmatically > maintaining a fetch request for the items array controller, based on > monitoring the selection of the account array controller, but I can't think > of any obvious way to do this without writing code. (A few lines of code, but > code nevertheless.) Chaining array controllers, and using the arrangedObjects > or selection properties as appropriate, should allow you to design the > interface codelessly. > > Does that sound like what you need? There was a different tutorial that > explored some of this, but I can't find it any more. > > > ___ > > 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/lists%40lastonepicked.com > > This email sent to li...@lastonepicked.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
