When binding A to B and B to A, get an iloop if both A and B change before dirtyCheck

[sorvell]

Given the following example, an iloop is generated.

Is this expected and if so, do we have a better way to achieve the desired A to B to A type of binding?

var A = { foo: 0 }; var B = { foo: 0 }; // Model.observe(A, 'foo', function(inNew) { if (loops++ > 5) { console.error("propagation circularity, aborting"); return; } console.log('propagating A.foo to B.foo; A.foo == %s, inNew = %s', A.foo, inNew); B.foo = inNew; }); Model.observe(B, 'foo', function(inNew) { console.log('propagating B.foo to A.foo; B.foo == %s, inNew = %s', B.foo, inNew); A.foo = inNew; }); // loops = 0; A.foo = 1; // adding this dirtyCheck avoids the iloop // Model.dirtyCheck() B.foo = 2; Model.dirtyCheck();

[sjmiles]

If MDV's proper semantics are to play back a history of changes as they occured, then the problem is entirely in your test code.

[rafaelw]

I don't think there's any way to prevent this, and we shouldn't attempt it.