ng-attr-poster does not work in video tag

[amitport]

Do you want to request a feature or report a bug?
bug

What is the current behavior?
ng-attr-poster is ignored on video tag

If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem via https://plnkr.co or similar (template: http://plnkr.co/edit/tpl:yBpEi4).
http://plnkr.co/edit/1QhnA9xb5BgyzWHpeL7O?p=preview

What is the expected behavior?
should see the poster image on video...

What is the motivation / use case for changing the behavior?
poster frame is needed for nice ux

Which versions of Angular, and which browser / OS are affected by this issue? Did this work in previous versions of Angular? Please also test with the latest stable and snapshot (https://code.angularjs.org/snapshot/) versions.
angular 1.5.8
win 7
chrome 53, IE 11, firefox 47

Other information (e.g. stacktraces, related issues, suggestions how to fix)
see related PR #4408

[amitport]

managed to make it work using

ng-attr-poster="{{'//placekitten.com/g/400/300'}}"
instead of
ng-attr-poster="placekitten.com/g/400/300"

Not sure if that was the intended behavior. In any case, it's not very intuitive

[Narretz]

ng-attr is for dynamic values / values that are on the scope. If your value is static, then you don't need ng-attr. Your working example initializes a useless watcher on the scope.

[amitport]

Of course I wasn't planning on keeping the hard coded value, but during some experimenting I was expecting to see some effect.

After looking at the implementation I see the root cause is allOrNothing interpolation behaviour (https://github.com/angular/angular.js/blob/v1.5.8/src/ng/interpolate.js#L162). IMHO, allOrNothing should return the value when there is nothing to interpolate (nothing interpolated still means that "all" interpolated to truthy values).

[Narretz]

Ok, if this is an issue with allOrnNothing, then please open a new issue / PR that explains the issue more generic.