IBOutlets Not Setting in NSViewController - xcode

So I've got an NSViewController (MyVC) set up like so:
//MyVC.h
...
#property (nonatomic, retain) IBOutlet NSTextField *input;
...
//MyVC.m
...
#synthesize input;
- (id)init
{
self = [super initWithNibName: #"MyVC" bundle: [NSBundle mainBundle]];
NSLog(#"%#", input); //prints (null) always
return self;
}
- (void)loadView
{
[super loadView];
NSLog(#"%#", input); //still (null)
}
...
//MyVC.xib
Custom View [Referencing Outlet: File's Owner.view]
Text Field [Referencing Outlet: File's Owner.input]
Now, when I load this NSViewController (by way of MyVC *vc = [[MyVC alloc] init];) and load it into a window, I see the Text Field appropriately. However, as the above paste (and several BAD_ACCESSes) would suggest, vc.input is never properly pointing to the Text Field.
Notes:
This project is running ARC.
This is not a simplification or generalization. I've run this exact code to no avail.
All IBOutlets are definitely set up appropriately.

The error was a combination of things.
One of my revisions was missing the IBOutlet tag, and none of them were retaining references to the ViewController at runtime.

Related

Why won't the data display in my NSTableView(view based)?

I followed the advice here on how to setup a MainWindowController: NSWindowController for my project's single window. I used a Cocoa class to create the .h/.m files, and I checked the option Also create .xib for User Interface. As a result, Xcode automatically hooked up a window, which I renamed MainWindow.xib, to my MainWidowController.
Next, I deleted the window in the default MainMenu.xib file (in Interface Builder I selected the window icon, then I hit the delete key). After that, I was able to Build my project successfully, and my controller's window in MainWindow.xib displayed correctly with a few buttons on it.
Then I tried adding an NSTableView to my MainWindowController's window. In Xcode, I dragged the requisite delegate and datasource outlets for the NSTableView onto File's Owner, which is my MainWindowController, and I implemented the methods in MainWindowController.m that I thought would make the NSTableView display my data:
- tableView:viewForTableColumn:row:
- numberOfRowsInTableView:
Now, when I Build my project, I don't get any errors, but the data doesn't appear in the NSTableView.
My code is below. Any tips are welcome!
//
// AppDelegate.h
// TableViews1
//
#import <Cocoa/Cocoa.h>
#interface AppDelegate : NSObject <NSApplicationDelegate>
#end
...
//
// AppDelegate.m
// TableViews1
//
#interface AppDelegate ()
#property (weak) IBOutlet NSWindow *window;
#property (strong) MainWindowController* mainWindowCtrl;
#end
#implementation AppDelegate
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
// Insert code here to initialize your application
[self setMainWindowCtrl:[[MainWindowController alloc] init] ];
[[self mainWindowCtrl] showWindow:nil];
}
- (void)applicationWillTerminate:(NSNotification *)aNotification {
// Insert code here to tear down your application
}
#end
...
//
// MainWindowController.h
// TableViews1
//
#import <Cocoa/Cocoa.h>
#interface MainWindowController : NSWindowController
#end
...
//
// MainWindowController.m
// TableViews1
//
#import "MainWindowController.h"
#import "Employee.h"
#interface MainWindowController () <NSTableViewDataSource, NSTableViewDelegate>
#property (strong) NSMutableArray* employees;
#property (weak) IBOutlet NSTableView* tableView;
#end
#implementation MainWindowController
- (NSView*)tableView:(NSTableView *)tableView
viewForTableColumn:(NSTableColumn *)tableColumn
row:(NSInteger)row {
Employee* empl = [[self employees] objectAtIndex:row];
NSString* columnIdentifier = [tableColumn identifier];
//The column identifiers are "firstName" and "lastName", which match my property names.
//You set a column's identifier by repeatedly clicking on the TableView until only
//one of the columns is highlighted, then select the Identity Inspector and change the column's 'Identifier' field.
NSString* emplInfo = [empl valueForKey:columnIdentifier]; //Taking advantage of Key-Value coding
NSTableCellView *cellView =
[tableView makeViewWithIdentifier:columnIdentifier
owner:self];
NSLog(#"The Table view is asking for employee: %#", [empl firstName]);
[[cellView textField] setStringValue:emplInfo];
return cellView;
}
- (NSInteger)numberOfRowsInTableView:(NSTableView *)tableView {
return [[self employees] count];
}
- (void)windowDidLoad {
[super windowDidLoad];
// Implement this method to handle any initialization after your window controller's window has been loaded from its nib file.
Employee* e1 = [[Employee alloc] initWithFirstName:#"Joe" lastName:#"Blow"];
Employee* e2 = [[Employee alloc] initWithFirstName:#"Jane" lastName:#"Doe"];
[self setEmployees:[NSMutableArray arrayWithObjects:e1, e2, nil]];
//Test to see if the employees array was populated correctly:
Employee* e = [[self employees] objectAtIndex:0];
NSLog(#"Here is the first employee: %#", [e firstName]);
//I see the output: "Here is the first employee: Joe"
}
- (id)init {
return [super initWithWindowNibName:#"MainWindow"];
}
- (id)initWithWindowNibName:(NSString *)windowNibName {
NSLog(#"Clients cannot call -[%# initWithWindowNibName] directly!",
[self class]
);
[self doesNotRecognizeSelector:_cmd];
return nil;
}
#end
...
//
// Employees.h
// TableViews1
#import <Foundation/Foundation.h>
#interface Employee : NSObject
#property NSString* firstName;
#property NSString* lastName;
- initWithFirstName:(NSString*)first lastName:(NSString*)last;
#end
...
//
// Employees.m
// TableViews1
//
#import "Employee.h"
#implementation Employee
- (id)initWithFirstName:(NSString *)first lastName:(NSString *)last {
if (self = [super init]) {
_firstName = first; //I read that you shouldn't use the accessors in init methods.
_lastName = last;
}
return self;
}
#end
File's Owner(=MainWindowController) connections:
NSTableView connections:
Response to comments:
Here is why calling [self tableView] reloadData] at the end of -windowDidLoad, as suggested in the comments, didn't work:
My _tableView instance variable--created by my #property declaration in MainWindowController.m--doesn't point to anything; therefore calling:
[[self tableView] reloadData]
I think is equivalent to calling:
[nil reloadData]
which doesn't do anything.
I never assigned anything to the _tableView instance variable in the -init method, nor did I assign it a value by dragging an outlet somewhere in Interface Builder. To fix that problem, I selected MainWindow.xib (the controller's window) in the Project Navigator(left pane), and then in the middle pane(Interface Builder), I selected the cube representing the File's Owner(selecting the Identity Inspector in the right pane reveals that the File's Owner is the MainWindowController). Then in the right pane, I selected the Connections Inspector, and it revealed an outlet called tableView, which is the IBOutlet variable I declared in MainWindowController.m.
Next, I dragged from the tableView outlet onto the TableView in the middle pane:
Doing that assigns the NSTableView object to the _tableView instance variable that was created by my #property declaration in MyWindowControler.m:
#property (weak) IBOutlet NSTableView* tableView;
As an experiment, I disconnected the outlet, then commented out the #property declaration for tableview, and the tableView outlet no longer appeared in the Connections Inspector. Also, if I change the declaration from:
#property (weak) IBOutlet NSTableView* tableView;
to:
#property (weak) NSTableView* tableView;
...then the tableView outlet doesn't appear in the Connections Inspector. That experiment answered a couple of questions I had about whether I should declare a property as an IBOutlet or not: if you need to assign one of the objects in Interface Builder to one of your variables, then declare the variable as an IBOutlet.
Thereafter, calling [self tableView] reloadData] at the end of -windowDidLoad succeeds in populating the TableView. However, I have not seen any tutorials that call reloadData, and even Apple's guide does not do that.
So, I am still puzzled about whether calling -reloadData is a hack or it's the correct way to do things.
Without it, your table view sits there blissfully clueless about your
expectation that it should even bother asking its datasource for data.
I assumed that an NSTableView automatically queries its datasource when it is ready to display itself, and that my code needed to be able to provide the data at that time.
I don't see you sending -reloadData to your table view anywhere. Tacking it onto the end of -windowDidLoad would be a good place. Without it, your table view sits there blissfully clueless about your expectation that it should even bother asking its datasource for data.
For all it knows, the data is simply not ready / available, so why would it try? More importantly, when should it try? It'd be rather rude of it to try whenever it pleases, considering the UI may not have finished loading / connecting to outlets, or its datasource may be in a vulnerable state (like teardown during/after dealloc) and sending datasource requests may result in a crash, etc.
Two things:
1st, set some breakpoints on when you set your employees array in windowDidLoad vs. when the table first attempts to populate itself and your numberOfRowsInTableView implementation gets called. If the latter happens before the former, then you'll need to add a reloadData after you create your array.
2nd, I personally always use NSCell instead of NSViews for my tables, so I always implement objectValueForTableColumn in my table's datasource. So I'm not sure if there's something different you need to do when you use NSView objects and implement viewForTableColumn. Is there a reason you're not using NSCell?

Why is NSViewController not binding representedObject?

In short: I bind an NSTextField to the File's Owner (the view controller) and Model Key Path of representedObject.firstName, but editing the text field does not change the firstName.
Here are more details. I have a simple program that does nothing but create an instance of Thing (a simple class with some properties), and ThingViewController. The controller has an associated .xib with a simple UI -- a couple text fields to bind to properties of the Thing.
#interface Thing : NSObject
#property (nonatomic, strong) NSString *firstName;
#property (nonatomic, strong) NSString *lastName;
#property (nonatomic) BOOL someBool;
#end
And in the app delegate...
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
NSView *cv = self.window.contentView;
ThingViewController *vc = [[ThingViewController alloc]
initWithNibName:#"ThingViewController" bundle:nil];
theThing = [Thing new];
theThing.firstName = #"Rob";
vc.representedObject = theThing;
[cv addSubview:vc.view];
}
The ThingViewController.xib is simple:
And here is the binding for that first text field:
When I run, the text field does show "Rob", so it works in that direction, but then as I edit the text field, the firstName property of theThing does not change.
What am I doing wrong?
Edit: Here's a link to a zipped project file for the above code: https://drive.google.com/file/d/0B2NHW8y0ZrBwWjNzbGszaDQzQ1U/edit?usp=sharing
Nothing is strongly referencing your view controller (ThingViewController), other than the local variable in -applicationDidFinishLaunching:. Once that goes out of scope, the view controller is released and dealloc'ed. The view itself is still around, since it is a subview of your window's contentView.
Once your view controller is released/gone, the text field has no connection back to the Thing object so it is in effect calling [nil setValue:#"New first name" forKeyPath:#"representedObject.firstName"].
Add a strong reference to your view controller (e.g., an instance variable of your app delegate) and try it again.
#implementation AppDelegate {
Thing *theThing;
ThingViewController *vc;
}
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
NSView *cv = self.window.contentView;
vc = [[ThingViewController alloc] initWithNibName:#"ThingViewController" bundle:nil];
theThing = [Thing new];
theThing.firstName = #"Rob";
vc.representedObject = theThing;
[cv addSubview:vc.view];
}

XCode Multiple implementations in separate views with UITextView not updating

Hey I just had a question regarding XCode's behavior with multiple views implementing the same UIView class of my own creation. I am working with a tabbed application and controller, and I have multiple views on the storyboard, all of which implement a class that I created. On one of the views, I have a text field and a button, and on another, I have a text view with a startup text reading "Waiting...". As you can probably guess, I want to enter text into the text field on the first view, press the button, then display the proper output text in the textview on the other view.
My question is: is there a problem with implementing the same class between multiple views?
I have researched numerous discussions on the TextView method of setting text inside of it, but all of the suggestions between the forums say something different, and none of the methods seem to work appropriately.
[textView setText string] doesn't want to work when I switch to the other tab,
textView.text = #"Message here" doesn't work either
I'd appreciate your help, and I've attached my code for reference.
#import "MasterController.h"
#interface MasterController ()
#end
#implementation MasterController
#synthesize input;
#synthesize output;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
}
- (void)viewDidUnload
{
[self setInput:nil];
[self setOutput:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
- (IBAction)generate:(id)sender
{
[output setText:input.text];
}
- (IBAction)textFieldReturn:(id)sender
{
[sender resignFirstResponder];
}
- (void)dealloc
{
[input release];
[output release];
[super dealloc];
}
#end
//MasterController.h
#import <UIKit/UIKit.h>
#interface MasterController : UIViewController
- (IBAction)generate:(id)sender;
- (IBAction)textFieldReturn:(id)sender;
#property (retain, nonatomic) IBOutlet UITextField *input;
#property (retain, nonatomic) IBOutlet UITextView *output;
#end
If you have several views that are controlled by the same view controller, they will not communicate with each other in the way that you are trying to make them. When you call [output setText:input.text] , you are saying: set the text for the output text field for the view that you are currently on.
One somewhat hacky way of getting around this is to create a second view controller and have it inherit from your "Master." Variables are set as protected as default and will retain their information when subclassed.
If you want to communicate between the different view controllers properly, however, you should look into state injection in this question: What's the best way to communicate between view controllers? Or use a communication system such as NSNotification center. Or you could use NSCoding, all of which are fairly easy to implement.

UILabel subclass

I know that this is a newbie question but I am a newbie so here goes:
I wish to use Chalkduster font quite a lot throughout my app (buttons, labels etc) and have tried subclassing UILabel to achieve this. I have the following in Default.h:
#import <UIKit/UIKit.h>
#interface Default : UILabel
{
UILabel *theLabel;
}
#property (nonatomic, strong) IBOutlet UILabel *theLabel;
#end
and this in my .m:
#import "Default.h"
#implementation Default
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
UIFont *custom = [[UIFont alloc] init];
custom = [UIFont fontWithName:#"Chalkduster" size:18];
self.font = custom;
NSLog(#"h");
}
return self;
}
#end
When I change the class in interface builder and run, I'm not seeing the Chalkduster font. I'd appreciate a hand in getting this set up as I believe it will save me a lot of time.
Cheers.
Some problems to fix:
1) You're mixing up the idea of Default being a label and Default containing a label. To subclass, get rid of the property inside your class and make your changes to self rather than theLabel (inside the if (self) { section).
2) Anything you code after an unconditional return isn't going to get executed...and I'm surprised the compiler didn't complain about those statements.
Edit: ...and one more thing that just dawned on me.
3) If you're loading from a xib or storyboard, the initialization is done by initWithCoder: instead of initWithFrame:, so:
- (id)initWithCoder:(NSCoder *)coder {
self = [super initWithCoder:coder];
if (self) {
self.font = [UIFont fontWithName:#"Chalkduster" size:18];
}
return self;
}
First of all I don't think that You're subclassing UILabel correctlly. So I made tutorial for You explaining how to do it. You don't need to IBOutlet object which is subclassed. JUST CALL IT WITH SELF. for example: self.font = ... If You want to subclass UILabel do this:
Create new class with title myLabel like this:
.h
#import <UIKit/UIKit.h>
#interface MyLabel : UILabel {
}
#end
.m
#import "MyLabel.h"
#implementation MyLabel
-(void)awakeFromNib {
UIFont *custom = [[UIFont alloc] init];
custom = [UIFont fontWithName:#"Chalkduster" size:18];
self.font = custom;
}
#end
Now select Your label in storyboard and go to indentity inspector and in Custom Class select created class above. Like this:
Output:
Note: Don't forget to release custom because You are allocating it.
Move the return self; three lines down. You return from the init method before you do your custom initialization.
Edit to reflect new information from comment:
When deserializing the view from a nib you also have to override initWithCoder:

NSTableView not Populating

I've been trying to get this NSTableView to populate for the last 7 hours. I am trying to get a list of all the currently running application and put them into an NSTableView. Eventually I would like to parse the resultes and organize the PID in one column and the Application Bundle in the other. I am getting an EXC_BAD_ACCESS error on " return [listOfWindows objectAtIndex:row];" I am currently using Xcode 4.3.2 and running OS X Lion 10.7.4. Thanks in advance everyone!
#interface AppDelegate : NSObject <NSApplicationDelegate>
{
IBOutlet NSMenu *statusMenu;
IBOutlet NSButton *button;
IBOutlet NSWindow *menuWindow;
IBOutlet NSTableView *proTable;
NSArray *listOfWindows;
IBOutlet NSArrayController *arrayController;
AppDelegate *mainMenu;
NSWorkspace *workSpace;
NSStatusItem *statusItem;
}
#property (assign) IBOutlet NSWindow *window;
-(IBAction)loadConfig:(id)sender;
#end
#import "AppDelegate.h"
#implementation AppDelegate
#synthesize window = _window;
- (void) awakeFromNib
{
[[NSDistributedNotificationCenter defaultCenter] addObserver:self
selector:#selector(loadMenu:)
name:#"WhiteBox"
object:nil];
[self addStatusItem];
//[proTable setDataSource:self];
listOfWindows = [[NSWorkspace sharedWorkspace] runningApplications];
NSLog(#"index %#", listOfWindows);
int y = 0;
y = [listOfWindows count];
NSLog(#"y = %d", y);
[proTable setAllowsMultipleSelection:YES];
}
-(void)applicationWillTerminate
{
NSLog(#"Will Terminate");
}
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
}
-(void)applicationDidResignActive:(NSNotification *)notification
{
NSLog(#"Resign Active");
}
-(void) addStatusItem
{
//Create a variable length status item from the system statusBar
statusItem = [[NSStatusBar systemStatusBar] statusItemWithLength:NSVariableStatusItemLength];
[statusItem retain];
//Set a Title for it
[statusItem setTitle:#"Status Item"];
//Set an Image and an alternate image
//[statusItem setImage:[NSImage imageNamed:#"lnc"]];
//[statusItem setAlternateImage: [NSImage imageNamed:#"status"]];
//Add a Tool Tip
[statusItem setToolTip:#"Status Item Tooltip"];
//Choose to highlight the item when clicked
[statusItem setHighlightMode:YES];
//To Trigger a method on click use the following two lines of code
[statusItem setMenu:statusMenu];
//[statusItem setAction:#selector(loadMenu:)];
}
-(IBAction)loadConfig:(id)sender
{
if(! [menuWindow isVisible] )
{
[menuWindow makeKeyAndOrderFront:sender];
} else {
[menuWindow performClose:sender];
}
}
- (NSInteger)numberOfRowsInTableView:(NSTableView *)tableView
{
return [listOfWindows count];
}
- (id)tableView:(NSTableView *)tableView
objectValueForTableColumn:(NSTableColumn *)tableColumn
row:(NSInteger)row
{
return [listOfWindows objectAtIndex:row];
}
#end
What object is the table view's data source? I don't see any object in the source you posted as implementing the NSTableViewDataSource protocol.
Further, have you tried putting breakpoints in the various data source methods to see if the debugger stops in them? If not, it's usually a good sign that your data source isn't connected to your table view.
I got: -[NSRunningApplication copyWithZone:]: unrecognized selector error when I ran your code. This could be fixed by changing your return line in tableView:objectValueForTableColumn:row: to
return [[listOfWindows objectAtIndex:row]localizedName];
NSRunningApplication doesn't conform to NSCopying, so I don't know if you can put instances of that class in a table view. However, you can get its properties like localizedName, processIdentifier, and bundleIdentifier.
I've run into this problem before with classes that don't implement NSCopying, I'd be happy to know if anyone knows a way to use these classes in table views or outline views.

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