Travis Griggs Travis Griggs - 4 months ago 13
iOS Question

How to embed a custom view xib in a storyboard scene?

I'm relatively new in the XCode/iOS world; I've done some decent sized storyboard based apps, but I didn't ever cut me teeth on the whole nib/xib thing. I want to use the same tools for scenes to design/layout a reusable view/control. So I created my first ever xib for my view subclass and painted it up:

enter image description here

I have my outlets connected and constraints setup, just like I'm used to doing in the storyboard. I set the class of my

File Owner
to that of my custom
UIView
subclass. So I assume I can instantiate this view subclass with some API, and it will configured/connected as shown.

Now back in my storyboard, I want to embed/reuse this. I'm doing so in a table view prototype cell:

enter image description here

I've got a view. I've set the class of it to my subclass. I've created an outlet for it so I can manipulate it.

The $64 question is where/how do I indicate that it's not enough to just put an empty/unconfigured instance of my view subclass there, but to use the .xib I created to configure/instantiate it? It would be really cool, if in XCode6, I could just enter the XIB file to use for a given UIView, but I don't see a field for doing that, so I assume I have to do something in code somewhere.

(I do see other questions like this on SO, but haven't found any asking for just this part of the puzzle, or up to date with XCode6/2015)

Update



I am able to get this to kind of work by implementing my table cell's
awakeFromNib
as follows:

- (void)awakeFromNib
{
// gather all of the constraints pointing to the uncofigured instance
NSArray* progressConstraints = [self.contentView.constraints filteredArrayUsingPredicate: [NSPredicate predicateWithBlock:^BOOL(id each, NSDictionary *_) {
return (((NSLayoutConstraint*)each).firstItem == self.progressControl) || (((NSLayoutConstraint*)each).secondItem == self.progressControl);
}]];
// fetch the fleshed out variant
ProgramProgressControl *fromXIB = [[[NSBundle mainBundle] loadNibNamed:@"ProgramProgressControl" owner:self options:nil] objectAtIndex:0];
// ape the current placeholder's frame
fromXIB.frame = self.progressControl.frame;
// now swap them
[UIView transitionFromView: self.progressControl toView: fromXIB duration: 0 options: 0 completion: nil];
// recreate all of the constraints, but for the new guy
for (NSLayoutConstraint *each in progressConstraints) {
id firstItem = each.firstItem == self.progressControl ? fromXIB : each.firstItem;
id secondItem = each.secondItem == self.progressControl ? fromXIB : each.secondItem;
NSLayoutConstraint *constraint = [NSLayoutConstraint constraintWithItem: firstItem attribute: each.firstAttribute relatedBy: each.relation toItem: secondItem attribute: each.secondAttribute multiplier: each.multiplier constant: each.constant];
[self.contentView addConstraint: constraint];
}
// update our outlet
self.progressControl = fromXIB;
}


Is this as easy as it gets then? Or am I working too hard for this?

Answer

You're almost there. You need to override initWithCoder in your custom class you assigned the view to.

- (id)initWithCoder:(NSCoder *)aDecoder {
    if ((self = [super initWithCoder:aDecoder])) {
        [self addSubview:[[[NSBundle mainBundle] loadNibNamed:@"ViewYouCreated" owner:self options:nil] objectAtIndex:0]];
    }
    return self; }

Once that's done the StoryBoard will know to load the xib inside that UIView.

Here's a more detailed explanation:

This is how your UIViewController looks like on your story board: enter image description here

The blue space is basically a UIView that will "hold" your xib.

This is your xib:

enter image description here

There's an Action connected to a button on it that will print some text.

and this is the final result:

enter image description here

The difference between the first clickMe and the second is that the first was added to the UIViewController using the StoryBoard. The second was added using code.

Here's an example project for your to play with: http://tinyurl.com/muqeuue