Can I use autolayout to provide different constraints for landscape and portrait orientations?

Question

Is it possible to change the constraints when the device is rotated? How might this be achieved?

A simple example might be two images which, in portrait, are stacked

Answer 1

My idea is to handle orientation by changing constraint priorities.
Supposing priorities will be:

• landscape: 910 active / 10 inactive.
• portrait: 920 active / 20 inactive.

Step 1: Create landscape (or portrait) design in Storyboard with constraints.
Step 2: For constraints, that must be active only for landscape mode set priority to 10.
Step 3: Add constraints for portrait mode and set their priority to 920.

In willAnimateRotationToInterfaceOrientation add code:

for (NSLayoutConstraint *constraint in myView.constraints) {
    if (UIInterfaceOrientationIsLandscape(UIApplication.sharedApplication.statusBarOrientation)) {
        if (constraint.priority == 10)  constraint.priority = 910;
        if (constraint.priority == 920) constraint.priority = 20;
    } else {
        if (constraint.priority == 20)  constraint.priority = 920;
        if (constraint.priority == 910) constraint.priority = 10;
    }
}

Advantage of this approach - easy adjusting in Interface Builder. When we need to switch to any orientation, we select all constraints by priority and change them simultaneously (910->10, 20->920):

Interface will rebuilded automatically.