CODEWITHSUNDEEP
angulartypescriptrxjs
lg0173
lg0173

Reputation: 234

Filter Observable<Any>

I work with Typescript and angular 4. I have 2 list (rxjs/Rx)

...
 myList: Observable<MyClass[]>;
 filteredList: Observable<MyClass[]>;
...

I want filtered myList and push result in the filteredList by looking at the property string of MyClass is equal to '123' or another string The filteredlist is mapped on a autcomplete angular and I have this code

 this.filteredList= this.myForm.get("myautocomplete").valueChanges .startWith(null) .map(???);

What's the best way to resolve this problem?

I can not do it !

Thanks for your help

Upvotes: 0

Views: 1742

Answers (3)

Sasxa
Sasxa

Reputation: 41274

This should do it:

myList: Observable<MyClass[]>;
filteredList = myList.map(items => 
  items.filter(item => item.string === '123'));

Autocomplete example:

filteredList = myForm.get("autocomplete").valueChanges 
  .startWith('')
  .combineLatest(myList)
  .map(([q, items]) => items.filter(item => item.string === q));

Upvotes: 3

Dmitry Efimenko
Dmitry Efimenko

Reputation: 11203

You have two observables. You want to take first one and transform it to a bit. You can use methid .map for it.

filteredList = myList.map(arr => arr.filter(x => x['stringPropOfMyClass'] === '123'));

I suggest you first get the basics of Observables down.

Upvotes: 0

Quentin Laill&#233;
Quentin Laill&#233;

Reputation: 125

Well, since typescript is based on JS, so if you want to know if there's a method to do this or that, go check it out.

You want to use .filter on an array :

-From MDN :

The filter() method creates a new array with all elements that pass the test implemented by the provided function.

So if you want to filter the number 0 on the array [0,1,2,3] named ar for instance :

filteredAr = ar.filter(entry => entry !== 0);

But since its an observable, you have to subscribe to its changes and change filteredList type...

Upvotes: 1

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