NgUpgrade Performance Issues

[tcrite]

Hi I'm working on a project to upgrade an AngularJs app to Angular 5 using ngupgrade. I had vs-repeat installed prior to the upgrade and it worked fined. However, since installing Angular 5 and bootstrapping Angular and AngularJs accordingly, I'm getting extremely poor performance from vs-repeat. Almost to the point where it's unusable. Was wondering if it could have something to do with AngularJs and Angular competing over change detection? Thanks and any help would be much appreciated.

[m3Lith]

I'm having the same issue currently. Did you manage to do something by any chance?

[tcrite]

@m3Lith if I comment this line out in my polyfills.ts file:

import 'zone.js/dist/zone'; // Included with Angular CLI.

it works ok. haven't had any ill effects from it yet, but I get the feeling it's not ideal

[m3Lith]

@tcrite but above that it says "Zone JS is required by default for Angular itself." and it throws an error inside console: "Error: In this configuration Angular requires Zone.js".

Does it really work for you with that one change?

[tcrite]

@m3Lith you are right. I just realized I added an import for zone.js in my main.ts file. Seems. to fix the configuration error thrown when you comment it out in the polyfills file

import 'zone.js';

[dfitoussi]

I comment the line out and added import 'zone.js'; but still, have poor performance.

[jziggas]

It has to do with this snippet:

$scope.$watch(() => {
          if (typeof window.requestAnimationFrame === 'function') {
            window.requestAnimationFrame(reinitOnClientHeightChange);
          } else {
            reinitOnClientHeightChange();
          }
});

If you profile your app and drill down you will probably see something like zone.js -> Animation Frame Fired -> Recalculate Style (angular-vs-repeat) due to this hook into window.requestAnimationFrame. Unfortunately I don't have a good solution, we were forced to remove this package because it brought our app to an unusable crawl.

[m3Lith]

@jziggas: have you tried uncommenting/adding this line in polyfills.ts?

(window as any).__Zone_disable_requestAnimationFrame = true;

It didn't help me, but I wonder if you would see a difference.

[jziggas]

I don't have a polyfills.ts in my project so I'm not sure where that would go.

[m3Lith]

You're including zone.js somewhere though? Try adding that line before the import of it.

[ghost]

Just encountered this issue, I can confirm @m3Lith's suggestion works

[jkainth]

Had the same issue. Disabling request animationframe on the zone didn't make sense - since it would mess with other places which use it. Instead i just forked the vs-repeat and commented the line contents of the $watch except for the reinitOnClientHeightChange; A bit of perf hit on vs-repeat, better than a blow up.

[amalitsky]

As of now angular-vs-repeat virtually doesn't work in angularJS/angular hybrid mode due to constant $digest re-triggering.

@kamilkp, would this be considered as a reasonable fix in the form of PR? Thanks

function angularHybridModeIsOn() {
  return '$$UpgradeModule' in $element.injector().modules;
}

$scope.$watch(function () {
  if (typeof window.requestAnimationFrame === 'function' && !angularHybridModeIsOn()) { 
    window.requestAnimationFrame(reinitOnClientHeightChange);
  } else {
    reinitOnClientHeightChange();
  }
});