Outdated operator-creation.md doc

[martinsik]

Documentation Related To Component:

/doc/operator-creation.md

Please check those that apply

• typo
• documentation doesn't exist
• documentation needs clarification
• error(s) in example
• needs example

Description Of The Issue

There's one outdated document at /doc/operator-creation.md. It was last updated on Dec 15th 2017 and still recommends patching Observable.prototype. Someone on StackOverflow mentioned that when you google for "rxjs custom operator" this is the first result.

It seems like most of its content is already covered in https://github.com/ReactiveX/rxjs/blob/master/doc/pipeable-operators.md#build-your-own-operators-easily.

[niklas-wortmann]

So in the new docs we have the guides about operators in general, see https://github.com/ReactiveX/rxjs/blob/master/docs_app/content/guide/operators.md#creating-custom-observables. I just took a quick look at the content of this chapter and it looks quite good for me. If you have any suggestions to improve this, just let me know

[martinsik]

I was mostly concerned about this part: https://github.com/ReactiveX/rxjs/blob/master/doc/operator-creation.md#adding-the-operator-to-observable

It mentions for example this which is obsolete now:

Patch Observable.prototype directly:
Observable.prototype.mySimpleOperator = mySimpleOperator;

[benlesh]

#5592 deals with this.

[jakovljevic-mladen]

The entire /doc folder is removed with the PR #5338. The content of that folder was used for the old docs site. It is now replaced with the new app which is located under /docs_app folder. Much like @niklas-wortmann said in this comment, the guide for creating custom operators is now moved to this file: /docs_app/content/guide/operators.md.

That file does not mention anything related to the problem described in this issue, so I'm gonna close this as outdated. Thanks for reporting.