Angular 8：同步/顺序运行组件 Class 方法

Question

How do I run methods synchronously in Angular Typescript? These are not functions, but methods. First one calls a service, and then second saves into an array.

runTwoMethods()
{
  this.validateAddress();
  this.saveJsonArchive();
}

Validate address may call more sub-method,may not even be Api, so want to wait until everything completes before saving.

Following syntax is for functions, currently searching for class methods,

Angular / TypeScript - Call a function after another one has been completed

At the end, data is stored into a current data object. And I want to be save to an archive. Maybe another possibility, how do I keep AddressCurrentMailing and JSONArchive[2] in sync?

Current Data object is sourced from API, not sure where (nor I am not allowed to edit the APIs, then calls transformations), and then would like to save into JsonArchive.

 this.jsonArchive[this.jsonArchiveCounter] = this.addressCurrentMailingFinalData

Answer 1

You can use Observable for the 1st and use your 2nd method after Subscribe in callback:

validateAddress(): Observable<Someclassname>
{
    return this._http.get<Someclassname>('url');
}

this.yourService.validateAddress().subscribe(
                (result) => { 
                  this.saveJsonArchive();
                },
                (error) => console.log('NO saveJsonArchive'));

EDIT ( validateAddress with more one Observable )

const ox: Observable<Someclassname>[] = [];
ox.push(this.http.get<Someclassname>(url1));
ox.push(this.http.get<Someclassname>(url2));
ox.push(this.http.get<Someclassname>(url3));
forkJoin(ox).subscribe(result => this.saveJsonArchive());

Answer 2

You could return a Promise in "this.validateAddress();" and await it.

I assume you use the Angular HttpClient.

For example:

private validateAddress(): Promise<someclassname>
{
    return this._http.get<someclassname>("someurl").toPromise()
}


async addSeasonal()
{
    await this.validateAddress();
    await this.saveJsonArchive();
}

I hope this helps.