CODEWITHSUNDEEP
angular
methuselah
methuselah

Reputation: 13206

Cannot read property 'subscribe' of null

I am trying to subscribe to the following method which reads data from a json file:

  getDefaultNavbarStyle(templateId): any {
    let template = null;
    switch (templateId) {
      case ActiveTemplates.Default:
        this.httpClient.get(this.DEFAULT_TEMPLATE_PATH).subscribe(response => {
          template = response;
        });
        break;
      case ActiveTemplates.Quick:
        this.httpClient.get(this.QUICK_TEMPLATE_PATH).subscribe(response => {
          template = response;
        });
        break;
      case ActiveTemplates.Front:
        this.httpClient.get(this.FRONT_TEMPLATE_PATH).subscribe(response => {
          template = response;
        });
        break;
      default:
        break;
    }
    return template;
  }

From another component:

this.defaultNavbarStyleSubscription = this.builderNavbarService.getDefaultNavbarStyle(this.navbarTemplate).subscribe(response => {
  if (response) {
    this.defaultNavbarStyle = response;
  }
});

However, I keep getting the following error:

ERROR TypeError: Cannot read property 'subscribe' of null

What can I do to fix it? I've initialized template as null but set its value in the switch statement.

Upvotes: 0

Views: 1228

Answers (2)

Ling Vu
Ling Vu

Reputation: 5181

By having a method to make a request you are usually return the Observable<any> to subscribe to it as a caller:

Change it to:

Method:

getDefaultNavbarStyle(templateId): Observable<any> {
    switch (templateId) {
      case ActiveTemplates.Default:
        return this.httpClient.get(this.DEFAULT_TEMPLATE_PATH)
      case ActiveTemplates.Quick:
        return this.httpClient.get(this.QUICK_TEMPLATE_PATH)
      case ActiveTemplates.Front:
        return this.httpClient.get(this.FRONT_TEMPLATE_PATH)
    }
  }

Caller:

this.defaultNavbarStyleSubscription = this.builderNavbarService.getDefaultNavbarStyle(this.navbarTemplate).subscribe(response => { this.defaultNavbarStyle = response; });

Upvotes: 1

Andrei
Andrei

Reputation: 11951

just add template = to each case and erase .subscribe

case ActiveTemplates.Default:
    return this.httpClient.get(this.DEFAULT_TEMPLATE_PATH);
case ActiveTemplates.Quick:
    return ...

Upvotes: 1

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