MutationObserver Error

[MurhafSousli]

• I'm submitting a ...

- [x] bug report

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

I think it is a bug

• What is the current behavior?

ERROR ReferenceError: MutationObserver is not defined

• **If the current behavior is a bug, please provide the steps to reproduce

this.observer = new MutationObserver((mutations: MutationRecord[]) => {
   mutations.forEach(() => {
      // ....
   });
});
const config: MutationObserverInit = {
  // ...
};
this.observer.observe(this.el.nativeElement, config);

• What is the expected behavior?

No errors

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

• Please tell us about your environment:

• Angular version: 5.X
• Browser: all
• Language: all
• OS: all
• Platform: NodeJs

I tried MutationObserver polyfill, but that one throws another error because it uses window so it won't help in Universal.

I also found this old issue here fgnass/domino#80

Is there a workaround or anything I can do to fix it?

[robisim74]

MutationObserver is an event on the objects of the DOM, so it is doesn't exist during SSR. Only way I found is detecting before using it:

        if (typeof MutationObserver !== "undefined") {
           this.observer = new MutationObserver((mutations: MutationRecord[]) => {
           ...
           });
        }

[CaerusKaru]

@robisim74's solution is correct. Domino (the SSR DOM) has no implementation of MutationObserver, although there is an ancient issue open for it in the Domino repo. But this is definitely not a Universal issue, so closing.

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