Store: Support for observable selectors e.g. let

[stephenlautier]

This is a...

• [x] feature request
• [ ] bug report
• [ ] usage question

What toolchain are you using for transpilation/bundling?

• [ ] @angular/cli
• [x] Custom @ngTools/webpack
• [ ] Raw ngc
• [ ] SystemJS
• [ ] Rollup
• [ ] Other

Environment

NodeJS Version: Typescript Version: Angular Version: @angular-redux/store version: @angular/cli version: (if applicable) OS:

Expected Behaviour:

Would be nice to have a feature which allows you to write selectors which can handle additional observable logic.

e.g.

isAuthenticated$() {
    return (state$: Observable<SharedState>): Observable<boolean | undefined> =>
        state$.map(x => x.auth.isAuthenticated)
        .filter(x => x !== undefined);
}

// and used as following
store.select(this.selector.isAuthenticated$())
   .do(...);

// or 
store.let(this.selector.isAuthenticated$())
   .do(...);

This was supported in ngrx and it was quite useful.

Actual Behaviour:

Currently, in order to make it work I need to use it as follows:

this.store.select(x => x)
    .let(this.selector.isAuthenticated$())

Stack Trace/Error Message:

Additional Notes:

(optional)

[gregkopp]

Can't you use the @select$ decorator to do this?

[stephenlautier]

I don't think you get what I want with that. What I want is to create a reusable selector and add additional filters etc.. on the observable. With the decorator you still wont have access to it as an observable but only as a function