I have a project that has a Entity called : Verse. The Verse (entity) has a Attribute called : VerseContent (String). I have it successfully linked to a Table View and I have a Search Bar on the top. The Table View is binded to VersesArrayController (NSArrayController which has it's Managed Object Context binded to my App Delegate's Managed Object Context). I don't really want to write any code and I recall that this is possible through Cocoa Bindings. How should I bind this Search Bar and my NSTableView together?
Thanks~
Bind the NSSearchField Predicate to VersesArrayController, and leave Model Key Path empty. You'll find Predicate under "Search" in the bindings tab. Then set the Predicate Format to:
verseContent contains $value
Checking Validates Immediately will give you live searching, leaving it unchecked requires you to hit Enter (or some other form of 'Submit').
Related
I'm attempting to use Cocoa bindings to populate an NSTableView using Core Data entities. I've arrived at a point where I'm boggled by the behavior of my application. The array controller is in "Entity Name" mode and is using the my "Song" entity.
The table view I am attempting to load the data into has two columns: one for the song name and another for the artist name (the artist is another entity which has a relationship to a song). Through Interface Builder, I have been able to successfully bind the array controller to the table, and setup bindings for the two columns. However, for some reason, one of the columns' bindings is working perfectly (artist name) while the other is not populating at all (song name).
I have gone through each view in the Document Outline and ensured that both columns are configured in exactly the same manner. I've attached some screenshots below showing the binding setup in Interface Builder.
Binding on the NSTableColumn representing the Song Title
Binding on the NSTextField within the NSTableCellView (the one that is not working)
Binding on the NSTextField for Artist Name (the one that is working)
The final (non-functioning) result
Is there an obvious reason why this approach is not working? Any help would be greatly appreciated. I can also provide any additional information that may be needed to answer this question.
It appears you are using a "view" based NSTableView as opposed to the older "cell" based. Each have a different configuration for bindings. In a view based table view you have to bind the tableview content to the array controllers arrangedObjects (see below), you don't have to deal with the individual column bindings that is for cell based table views.
Your remaining bindings look fine.
Just a wild guess. Since you're speaking of the Song entity.
Can it be that you have to bind the song name to objectValue.song.title?
If 'Artist' isn't just an attribute of the 'Song' entity but an entity itself (which it must likely be if it has a relationship to 'Song') then I think you need to have a separate array controller connected to that column in order for it to work properly.
Hey I am new to mac development and I want to use bindings (xcode 5.1.1).
I want to set the Title of a radio button dynamically by an entry of an array controller. I am looking for something like a syntax description how I can perform it.
e.g. something like value1 WHERE value2="bla"
If I trying to search at google I always find solutions which did it programmatically.
Is there anywhere some examples which show me the syntax I can use in this field?
The picture below should you show what I mean.
Answering the question as clarified in the comments…
First, bindings is not always the right technology. It can simplify some things, but it can't do everything and even for some of the things that it can do, it doesn't necessarily make them simpler.
Radio buttons are often organized in an NSMatrix. In that case, you can bind the matrix bindings to track the selection. There are three content-related bindings for a matrix, which can be kind of confusing. The "content" binding is the base. In some cases, it's sufficient. However, if there's a distinction between the object being bound and the value that should be shown by the cells of the matrix, then you can bind the "contentValues" binding to be a subpath of the content binding. That is, it needs to be the same as the content binding with possibly additional elements added to the end of the model key path.
Furthermore, if you want the selected object to be distinct from the content object, you can bind "contentObjects" to a subpath of the content binding.
For example, there may be an array controller whose content is a bunch of Person objects. The matrix content binding might be bound to that array controller's arrangedObjects. If you leave it like that, the cells of the matrix will be populated from the description of each Person object. However, you could bind the matrix's contentValues to the array controller, arrangedObjects, model key path fullName. Then, the matrix cells will be populated with the full name of each Person object.
If you then bind the matrix's selectedObject binding to a property on your window controller, that property will be set to the selected Person object each time the matrix selection changes. If you would prefer, you could bind the matrix's contentObjects binding to the array controller, arrangedObjects, model key path uniqueID. In that case, the window controller property would not be set to the selected Person object itself, but to its uniqueID property.
Alternatively, you could bind the matrix's selectedIndex binding to a controller property. If you use the window controller, then that just directly sets a property on the window controller to indicate the index of the matrix's selection. Or you could bind it to the array controller's selectedIndex property, in which case the selection is "stored" in the array controller.
You need a keypath that takes no parameter as described in the key-value coding (KVC) reference.
By binding to an array controller's selection, if the selection collection is one object with a property or method "value1," then the binding runtime is calling the method valueForKeyPath:#"value1".
The NSObject protocol has performSelector:withObject, but there is nothing like valueForKeyPath:withObject in the KVC protocol or the NSKeyValueBindingCreation protocol
That said, registering dependent keypaths can provide some equivalent behavior...
+ (NSSet*) keyPathsForValuesAffectingValue1
{
return [NSSet setWithObjects:#"value2",nil];
}
... and that would ensure that any time value2 changes, the binding to value1 is re-evaluated.
I want to bind selection of NSPopUpButton to one of the predefined values. To make it simpler, imagine a blog app: I'd have BlogPost and Category entities (Core Data, although it doesn't matter) and each BlogPost object has a link to one of the Category objects (through category property).
I want to have the user change the category through NSPopUpButton, so in my XIB, I have NSArrayController that holds all possible categories and I bind button's Content Values to:
Bind to: categoriesArrayController
Controller key: arrangedObjects
Model key: title
This nicely populates pop up with titles of all categories. I can also bind Selected Object to:
Bind to: blogObjectController (or directly to Blog object)
Controller key: selection
Model key: category
This works and correct category is selected in pop up, however changing selection doesn't change the category under which the blog post is filed, but instead changes the title of post category to the selected value.
Given the above bindings this actually makes sense, so my next step was to change the binding of pop up's content values to only arrangedObjects (no model key), similarly selected object. This works and changing selection does indeed change category of the blog post to another one. BUT it doesn't show category title in pop up menu, but instead shows the description of the category (which in Core data ends with something like <Category 0x1002b6990> (entity: Category; id: .......).
Which also makes sense, so I introduced custom NSValueTransformer (non-reversible). This fixes item descriptions in pop up menu, but then selection doesn't work. I also tried using the transformer on selected object binding, but that just disables my pop up entirely (perhaps reverse transform would be required, but this would substantially complicate transformer).
Am I missing something obvious - is this possible to achive entirely with bindings, without introducing additional code on controller layer?
Any though is welcome!
PS: hope above text makes sense :)
I would try it as follows:
Of NSPopupButton:
Bind Content to : categoriesArrayController ControllerKey: arrangedObjects
Bind Content Values to : categoriesArrayController ControllerKey: arrangedObjects Model Key Path: title
Bind Selected Object to : blogObjectController ControllerKey: (empty) Model Key Path: content.category
How do I bind NSDictionary objects to several text fields in Interface Builder?
I would like to bind each object to a specific item in the dictionary. For example, the first text field should be bound to Actor:
You need to add a NSObjectController in Interface Builder. In the attributes inspector tab leave the standard mode "Class" and class name on "NSMutableDictionary", but switch "Prepares Content" on. In the bindings inspector bind "Content Object" to "Shared User Defaults Controller", controller key "values" and "Model Key Path" to your dictionary's key in User Defaults. Switch "Handles Content As Compound Value" on.
Now you can bind your text field (or check boxes etc). values to the ObjectController, with controller key "selection" (!) and the keys in your dictionary (as model key path).
Hope this helps. I couldn't find the answer in Apple's documentation and also not in the net, was lucky to find it out myself by trying different controller objects...
First: #keeluu's answer should be marked correct.
Doing it Programmatically
If you're doing this in code rather than through IB, there's a "gotcha" to look out for. It looks like this:
// Assume 'anObjectController' is an NSObjectController.
// Assume 'userDefaultsController' is [NSUserDefaultsController sharedUserDefaultsController]
// Assume 'someDictionary' is an NSDictionary in userDefaults.
[self.anObjectController
bind:NSContentBinding
toObject:userDefaultsController
withKeyPath:#"values.someDictionary"
options:#{NSHandlesContentAsCompoundValueBindingOption: #YES}];
If you do the above, you'll find that when you bind your UI elements to properties in someDictionary, those UI elements will correctly display the values that are IN user defaults, but when you change them (by say, clicking a bound checkbox) those values will NOT be updated in user defaults; the old values stick around.
The Reason
The binding must be to NSContentObjectBinding instead of NSContentBinding. The NSObjectController class exposes a binding named contentObject. When you bind to that, everything works properly.
This is an easy mistake to make because Xcode's code completion automatically goes for NSContentBinding and it's one of the most frequently used binding names anyway. This just cost me hours of trouble, so hopefully I saved someone else some time.
Try to add NSDictionaryController to you .xib file, then bind its Controller Content to your dictionary in User Defaults. Then you can bind text field values to Dictionary Controller (arrangedObjects key).
I never tried that but I think it must work.
Hope, it helps.
After I drag a controller object to the document window, how do I give it a Boolean property?
Assuming you want the ability to expose and edit the property values of your custom controller as attributes showing up in IB's inspector, you'll need to write your own plugin which tells IB what the inspector should look like. This really can't be answered briefly.
Here's Apple's reference on IB Plugins:
http://developer.apple.com/mac/library/documentation/DeveloperTools/Conceptual/IBPlugInGuide/Introduction/Introduction.html#//apple_ref/doc/uid/TP40004323-CH1-SW1
And here's the inspector portion:
http://developer.apple.com/mac/library/documentation/DeveloperTools/Conceptual/IBPlugInGuide/CreatingInspectors/CreatingInspectors.html#//apple_ref/doc/uid/TP40004323-CH6-SW1
If you truly just want to add a property to the controller's interface, you do this in Xcode (modifying the interface and implementation accordingly) and IB will pick up the changes automagically.
In the case of a checkbox, the checkbox itself is either checked or not. That state stores the boolean value instead of the controller (unless you wish it.)
To have the app undertake an action upon clicking it, think of it as a button instead of a data display and link it to an action method in the view controller. That's the simplest and old school way of doing it.
To use binding, you need to bind the checkbox's value attribute to a controller. Usually for binary values its an object controller. So, in IB, drag an Object controller to your nib window and bind it to your data source. Then, drag a checkmark button to the interface. In the checkmarks binding inspector. Set "value" binding to the name of the object controller, controller key to selection, keypath to the name of the data source attribute and provide a value transformer if needed.