Adam Waite Adam Waite - 1 month ago 24
iOS Question

Correct way to load a Nib for a UIView subclass

I am aware this question has been asked before but the answers are contradicting and I am confused, so please don't flame me.

I want to have a reusable UIView subclass throughout my app. I want to describe the interface using a nib file.

Now let's say it's a loading indicator view with an activity indicator in it. I would like on some event to instantiate this view and animate in to a view controller's view. I could describe the view's interface no problem programmatically, creating the elements programmatically and setting their frame inside an init method etc.

How can I do this using a nib though? Maintaining the size given in interface builder without having to set a frame.

I've managed to do it like this, but I'm sure it is wrong (it's just a view with a picker in it):

- (id)initWithDataSource:(NSDictionary *)dataSource {
self = [super init];
if (self){
self = [[[NSBundle mainBundle] loadNibNamed:[NSString stringWithFormat:@"%@", [self class]] owner:self options:nil] objectAtIndex:0];
self.pickerViewData = dataSource;
[self configurePickerView];
}
return self;
}


But i'm overwriting self, and when I instantiate it:

FSASelectView *selectView = [[FSASelectView alloc] initWithDataSource:selectViewDictionary];
selectView.delegate = self;

selectView.frame = CGRectMake(0, self.view.bottom + 50, [FSASelectView width], [FSASelectView height]);


I have to manually set the frame rather than have it picked up from IB.

EDIT: I want to create this custom view in a view controller, and have access to control the view's elements. I don't want a new view controller.

Thanks

EDIT: I Don't know if this is best practice, I'm sure it's not, but this is how I did it:

FSASelectView *selectView = [[[NSBundle mainBundle] loadNibNamed:[NSString stringWithFormat:@"%@",[FSASelectView class]] owner:self options:nil] objectAtIndex:0];
selectView.delegate = self;
[selectView configurePickerViewWithData:ds];
selectView.frame = CGRectMake(0, self.view.bottom + 50, selectView.width, selectView.height);
selectView.alpha = 0.9;
[self.view addSubview:selectView];
[UIView animateWithDuration: 0.25 delay: 0 options:UIViewAnimationOptionAllowUserInteraction |UIViewAnimationOptionCurveEaseInOut animations:^{
selectView.frame = CGRectMake(0, self.view.bottom - selectView.height, selectView.width, selectView.height);
selectView.alpha = 1;
} completion:^(BOOL finished) {
}];


Correct practice still wanted

Should this have been done using a view controller and init with nib name? Should I have set the nib in some UIView initialisation method in the code? Or is what I have done ok?

Answer
MyViewClass* myViewObject = [[[NSBundle mainBundle] loadNibNamed:@"MyViewClassNib" owner:self options:nil] objectAtIndex:0]

I'm using this to initialise the reusable custom views I have..


Note that you can use "firstObject" at the end there, it's a little cleaner. "firstObject" is a handy method for NSArray and NSMutableArray.

Here's a typical example, of loading a xib to use as a table header. In your file YourClass.m

-(UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
    {
    UIView *view = [[[NSBundle mainBundle]
        loadNibNamed:@"TopArea"
        owner:self options:nil]
         firstObject];
    return view;
    }

Normally - in the TopArea.xib, you would click on File Owner and set the file owner to YourClass. Then actually in YourClass.h you would have IBOutlet properties. In TopArea.xib, you can drag controls to those outlets.

Don't forget that in TopArea.xib, you may have to click on the View itself and drag that to some outlet, so you have control of it, if necessary. (A very worthwhile tip is that when you are doing this for table cell rows, you absolutely have to do that - you have to connect the view itself to the relevant property in your code.)

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