Arnaldo Antonio Torres Arnaldo Antonio Torres - 1 month ago 10
TypeScript Question

Angular2 - Subscribe when two event emmitters emit

I have the following code for my component:

ngOnInit() {
this.route.params.forEach((params: Params) => {
this.codvis = params['id'];
});
this.objects.selectedObject.subscribe(obj => this.selectedEventObjet(obj));
this.sections.selectecSection.subscribe(section => this.selectedEventSection(section));
}

function selectedEventObjet(o) {
this.selectedObj = o;
}

function selectedEventSection(s) {
this.selectedSection = s;
}


So, now I want to call a service only when
selectedObj
and
selectedSection
are set, but it is not just simple as:

ngOnInit() {
this.route.params.forEach((params: Params) => {
this.codvis = params['id'];
});
this.objects.selectedObject.subscribe(obj => this.selectedEventObjet(obj));
this.sections.selectecSection.subscribe(section => this.selectedEventSection(section));
this.myService.getItems(this.selectedObj, this.selectedSection)
.subscribe(
items => this.items = items;
);
}


But I can not obtain the
items
.

How can I make sure that
selectedObj
and
selectedSection
are set to get the
items
?

Answer
Observable.combineLatest(this.objects.selectedObject, this.sections.selectecSection)
  .subscribe(([obj, section]) =>  this.myService.getItems(obj, section))

You don't even need your local handlers to keep the value, just get it straight of the sequences.