if binding evaluating to false delays invocation of koDescendantsComplete

[brimimc]

Migrating from knockout, I have component templates that have simple if binding checks like

<!-- ko if: showTabsList -->

if showTabsList is set to false, and we have a koDescendantsComplete() function, that function is never called. Only when showTabsList is set to true will koDescendantsComplete be called.

This appears to be similar behavior to knockout's completeOn: "render" option, but that's not what we want/need.

Is there any way to have koDescendantsComplete even when an if binding is bound to false?

[brimimc]

This may be fixed in latest - will need to get a release to test with

[brimimc]

Of note - we've found that the descendantsComplete binding handler applies TOO EARLY (before a child foreach has updated the DOM) - I'm not sure if the comment on the fix "Fix mirrors DescendantBindingHandler" if that will also be too early.

@phillipc any ideas when the next release will happen for me to test the updates? thanks

[phillipc]

Hey @brimimc, i think the DescendantsComplete-behavior is different in TKO.

Properly you can switch to childrenComplete: render, see here:

tko/packages/binding.core/spec/descendantsCompleteBehaviors.ts

Line 118 in f396518

it('TKO-Change: descendantsComplete callback function is not called after nested "if" binding', function () {

BTW: Have you already set the option createChildContextWithAs to false for your migration project (see #191)?

[brimimc]

Interesting @phillipc ... switching from descendantsComplete to childrenComplete could work for a single sub-component, but we have multiple and we need to wait for all of them to have childrenComplete before invoking our logic.

And yes we do have ko.options.createChildContextWithAs = true; set.

Any update on when the next release with koDescendantsComplete behavior fixes might be released?

[phillipc]

I couldn't stop thinking about this either. I've implemented a solution that restores the KO behavior.

@brianmhunt , please take a look at this. -> #416