Form object properties are not deleted

[Tobbe]

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

bug

What is the current behavior?

Angular leaves undefined object properties that should have been deleted

Demo: http://jsfiddle.net/Tobbe/8eohL2nq/2/

First press one of the "RemoveChild" buttons, then press "Trigger Error". Watch the output in your browser's console.

What is the expected behavior?

Seeing as Angular automatically adds the entire object property (i.e. vm.forms.formId0 and vm.forms.formId1 in the demo above) when the corresponding form is dynamically created, it should be completely removed (deleteed) when the form is dynamically removed.

What is the motivation / use case for changing the behavior?

Looping over the object with the generated forms should not cause JS errors. ("TypeError: Cannot read property '$valid' of undefined" in this case)

Which versions of Angular, and which browser / OS are affected by this issue?

Angular 1.4.6
Chrome Version 49.0.2623.112 m
Windows 7 Pro SP1

Also confirmed on latest snapshot (AngularJS v1.5.6-build.4771+sha.c95a3d8)

Have not tried with earlier version of Angular

Other information (e.g. stacktraces, related issues, suggestions how to fix)

No

[gkalpak]

The name attribute of a form dirrective is evaluated as an Angular expression.
Deleting a property should be done through the parser and it is not supported atm (and don't think it will be).

(Of course, you can always check before accessing a value or manually delete the keys when removing a form.)

[Tobbe]

Thanks for the reply.

Checking before accessing is what I do right now :) Not sure how I would go about manually deleting the keys though since in my real implementation the array I loop over to generate the forms and the object I use to store the form references in are two totally separate parts of my application (one is part of the model, and the other is part of the view/controller). Since it's angular itself that removes the form because of the data-binding to the model object I'm not sure where to hook in my code that would delete the property.

[gkalpak]

Not able to make any concrete suggestion without the actual code, but $index seems to be the "greatest common divisor". You should be able to use that.

[Tobbe]

Alright 👍 Don't worry about it :) Checking with angular.isDefined before accessing is good enough then!