select: ng-selected on a md-option is not working on page load

[p3x-robot]

Bug, enhancement request, or proposal

Bug

Working ng-selected with AngularJs Material 1.1.21
https://codepen.io/patrikx3/pen/mdeQEmY

Not working ng-selected with AngularJs Material 1.1.22
https://codepen.io/patrikx3/pen/QWjJEaK

Demo and steps to reproduce the issue

This blank StackBlitz demo can be used to create a reproduction that demonstrates your issue.

Demo URL (required)*: Working ng-selected with AngularJs Material 1.1.21 https://codepen.io/patrikx3/pen/mdeQEmY vs Not working ng-selected with AngularJs Material 1.1.22 https://codepen.io/patrikx3/pen/QWjJEaK

Detailed Reproduction Steps

Run https://codepen.io/patrikx3/pen/mdeQEmY and you can see, that AngularJs Material 1.1.21 select ng-selected is working properly.

Run the same exact same code but with AngularJs Material 1.1.22 version, it is not working.

Explain the expected behavior

Should work with ng-selected es it works in v1.1.21

Explain the current behavior

With v1.1.22, something changed and the ng-selected is not selecting the ng-model anymore as the url shows.

Discuss the use-case or motivation for changing the existing behavior

We have been using and updating AngularJs Material since like 1.0.0, but not we can't update anymore as it not working as it was.

List the affected versions of AngularJS, Material, OS, and browsers

• AngularJS: 1.7.9
• AngularJS Material: 1.1.21 vs 1.1.22
• OS: Linux
• Browsers: Chrome

Add anything else we should know

Stack Trace

No trace!

Screenshots

AngularJS Material: 1.1.21

AngularJS Material: 1.1.22

[Splaktar]

Investigation

In both examples, i see ng-selected working as described in this warning. I.e. ng-selected should only toggle the selected attribute on the md-option and it should not change the model value.

This example demonstrates the AngularJS-way of doing what is demonstrated in your demo (i.e. the value is set by the ng-model only and the selected attribute is managed by ngModel as well).

Your example code depends upon an undocumented behavior in md-select caused by using an unsupported API (ng-selected on md-option).

In this AngularJS-only example you can see that ng-selected doesn't cause the ng-model value to be set either. The one difference here is that it also doesn't change the display value of the select until you toggle the value of ng-selected on and off. But even then, it updates the view but it doesn't update the ng-model value.

A case could certainly be made for md-select to be more like select with AngularJS, in that it should not show the ng-selected option as selected in the view on initial load. But I think that behavior is also sub-optimal.

Findings

This change in behavior, where ng-selected does not cause the ng-model value to change, was introduced in 928c71d and this behavior wasn't discovered in 1.1.22-rc.0. This is likely due to the fact that using ng-model on md-select with ng-selected on md-options is not recommended or documented (notice that ng-selected is not found in the md-option docs.

[p3x-robot]

hello! we understand that is bad code, but we had many developers that have been using this ng-selected function and they have been using it for over 4 years this "legacy" app.
so how can we fix this? we should not update to material to 1.1.22 and anymore? it would be a huge re-write everything...