Trigger OnUpgrade

Example 1

In this example, this contract will only be updated if it's the owner that called it and reject anything else.

Make sure to add a validation like this, else your contract can be hacked and updated without your consent!

contract test {
    import Runtime;
    global owner: address;
    
    trigger onUpgrade(from:address)
    {
        Runtime.expect(Runtime.isWitness(owner), "Only the owner can update");
    }
}