Angular async OnInit

Question

I am really new to angular, and wanted to understand how can i call async on Oninit. I have one service which is using asyn/await. i want to be able to use this in OnInit. however, I am not able to use it. because before service call is complete code executes to next line and it throws ZoneawarePromise error.

My Service method looks like below

 public async getProjects():Promise<Observable<any>>{
    const querySpec = {query: "SELECT * from c"};
    const { resources:items } = await this.container.items.query(querySpec).fetchAll();
    return of(items);
  }

and this is how i am trying to call it within ngOnInit

async ngOnInit(){
      (await this.projectData.getProjects()).subscribe(data=>{
   
       //All the other code goes here, basically creating a HTML content

what could be the right way to call a service ?

Why are you turning your promise into an observable? return of(items);. getProjects should just return an Observable or a promise not both — Liam
– Liam, Commented Aug 17, 2020 at 15:09

Reza · Accepted Answer · 2020-08-17 15:06:37Z

1

your problem is Promise of Observable,

 public async getProjects():Promise<Array<any>>{
    const querySpec = {query: "SELECT * from c"};
    const { resources:items } = await this.container.items.query(querySpec).fetchAll();
    return items;
  }

then

async ngOnInit(){
      const data = await this.projectData.getProjects();
      console.log('data',data);

answered Aug 17, 2020 at 15:06

Reza

20.1k18 gold badges102 silver badges177 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

e2eDev Over a year ago

Thanks for the reply, Now, I am getting ERROR TypeError: Cannot read property 'toArray' of undefined.

e2eDev Over a year ago

I figured the issue. It was mainly because of not initialising the variables properly. once i did it. its working fine. Thanks

Collectives™ on Stack Overflow

Angular async OnInit

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related