UIView+DPCollapsibleConstraints builds to collapse a view and its relevant layout constraints, simulating a "Flow Layout" mode. UIView+DPCollapsibleConstraints is derived from UIView+FDCollapsibleConstraints，but UIView+DPCollapsibleConstraints only supports pure objective-c code, what's more, it's compatible with masonry!!

(UIView+DPCollapsibleConstraints act the same result comparing with UIView+FDCollapsibleConstraints) This demo collapses the forkingdog image view and its bottom margin constraint.

(UIView+DPCollapsibleConstraints act the same result comparing with UIView+FDCollapsibleConstraints)

This demo collapses diffent components in cell, according to its data entity, each margin handles right as well.

you should set dp_EnabelManualCollapsed to YES before you want to collapse the view;

@property(nonatomic,assign)BOOL dp_EnabelManualCollapsed;

###or if view like UILabel, UIImageView which have their Intrinsic content size,you can set dp_autoCollapse to YES;

@property (nonatomic, assign) BOOL dp_autoCollapse;

First, tell which constraints will be collapsed when the view collapses. and dp_NSLayoutAttributes is the collection of NSLayoutAttribute;

@property(nonatomic,copy)NSArray* dp_NSLayoutAttributes;

you can initial dp_NSLayoutAttributes in this way:

view.dp_NSLayoutAttributes = @[@(NSLayoutAttributeTop),@(NSLayoutAttributeHeight)];

Selected constraints will collapse when:

view.dp_collapsed = YES;

And expand back when:

view.dp_collapsed = NO;

Not every view needs to add a width or height constraint, views like UILabel, UIImageView have their Intrinsic content size when they have content in it. For these views, we provide a Auto collapse property, when its content is gone, selected constraints will collapse automatically.
You can enable auto collapse by:

label.dp_autoCollapse = YES;
imageView.dp_autoCollapse = YES;

And it will work as you expect:

label.text = nil/*or @""*/; (auto => label.dp_collapsed = YES)
label.text = @"forkingdog"; (auto => label.dp_collapsed = NO)
imageView.image = nil; (auto => imageView.dp_collapsed = YES)
imageView.image = [UIImage imageNamed:@"forkingdog"]; (auto => imageView.dp_collapsed = NO)

We've also offered a Interface Builder friendly way to enable auto collapse:

@property (nonatomic, assign) BOOL dp_autoCollapse;

Here's what you may find in Attribute Inspector

It's behavior is same as setting dp_autoCollapse property in code.

Cocoapods:

pod search UIView+DPCollapsibleConstraints

MIT