How to make Method process in sequence

[Sivaprakash Gopal]

Hi All,

I am new angular, how to make method processing as sequential. Based on api response, i need to navigate to different component.

In this case, how to make process sequential.

let responseObj = null;

let path = null;

buttonClick(){

method1();

router.navigateByURL(path);

}

method1(){

 responseObj =  api call();

 method2(responseObj);

}

method2(responseObj){

 path = processing - > responObj;

}

Thanks,

Siva

[Tito]

Method1().then(method2())

[Zlatko Đurić]

Hi Siva,

Your call to the method is sync, but the actual execution is async. Additionally, your method1 calls method2, which has what we call a side effect. (Setting that local path variable).

You can do several approaches here, e.g. use a promise, like Tito suggested:

    buttonClick() {

      method1()

          .then(() => {

              router.navigateByUrl(path);

           });

Of course, you also need to make method1 a promise that doesn't return until method2 with it's side effect is executed:

    method1() {

      return apiCall()

        .then(result => this.method2(result));

    }

Alternatively you can make your buttonClick an async function, then it might be easier to understand, so now (together with method1 change above), your buttonClick looks like this:

async buttonClick() {

    await method1();

    return router.navigateByUrl(path);

}

There are other ways to do this, but this should get you started.

Zlatko