NSLayoutConstraint code, done right

gistfile1.m

//Pass in arrays of views and access with number keys or add attributes for all
NSArray *views = @[ topView, middleView, lastView ];
[containerView setSubviews:views];
[containerView m3_addConstraints:@[
	@"$1.top = 0",
	@"$2.top = $1.bottom",
	@"$3.top = $2.bottom",
	@"$3.bottom = 0",
	@"$all.(left, right) = (0, 10)", //Assign multiple attributes in one statement
	@"$all.height >= 30"
] forViews:views];



//Use dictionaries for named variables. Special keywords "super" and "size" allow quick setting of
//padding to superview (top, leading, bottom, trailing) and view size (width, height)
[contentView addSubview:containerView];
[contentView m3_addConstraints:@[
	@"$container.super = (20, 0, 20, 0)", //20 from top & bottom, 0 from left & right
	@"$container.size <= (400, 300)"
] forViews:@{ @"container" : containerView }];



//Can access views via KVC.
[myView setContentView:contentView];
[myView m3_addConstraints:@[
	@"$self.contentView.super = 0" //If all values of a multiple attribute are equal can assign single constant
] forViews:nil];