Angular 2 TypeError: Cannot read property 'subscribe' of undefined

Question

I have a single form which is used to add a new event or edit an existing event. I check the URL parameter and if an id is present then I would like to subscribe to an editEvent method from my EventService, otherwise subscribe to addEvent method from EventService and add the new event. Adding an event works fine whereas if an ID is passed in the URL then i get an error like Cannot read property 'subscribe' of undefined. I am returning an observable in my editEvent method (same as in addEvent) and it is not nested inside another call. Below is my code.

<form class="form-horizontal" [formGroup]="addEventForm" (ngSubmit)="addEvent()">

event-entry.component.ts

addEvent() {
        console.log(this.addEventForm.value);
        if(this.editedEventId){
            console.log('editing event');
            //If the editedEventId is passed via url then we are Editing an event
          this.eventService.editEvent(this.editedEventId,this.addEventForm.value).subscribe(
                data => console.log(data),
                error => console.log(error)
            );
        }else{
            console.log('adding event');
            //else we are creating an event
             this.eventService.addEvent(this.addEventForm.value).subscribe(
                data => console.log(data),
                error => console.log(error)
            );
        }

        //to reset the form after submission
        this.addEventForm.reset();
    }

event.service.ts

addEvent(event:Events) {
        this.events.push(event);
        const body = JSON.stringify(event);
        const headers = new Headers({
            'Content-Type': 'application/json'
        });
        return this.http.post('http://localhost:3000/event', body, {
            headers: headers
        })
            .map((response:Response) => response.json())
            .catch((error:Response) => Observable.throw(error.json()));
    }

editEvent(eventId:number, event:Events){
        console.log('Entering editEvent in event service');
        let url = 'http://localhost:3000/event/'+eventId;
        const body = JSON.stringify(event);
        const headers = new Headers({
            'Content-Type': 'application/json'
        });
        return this.http.put(url, body, {
            headers: headers
        })
            .map((response:Response) => response.json())
            .catch((error:Response) => Observable.throw(error.json()));

    }

I am new to angular 2. I tried all solutions available online (like using switchMap) but none worked. The full stack trace of the error.

ERROR TypeError: Cannot read property 'subscribe' of undefined
    at EventEntryComponent.addEvent (eval at <anonymous> (bundle.js:901), <anonymous>:120:86)
    at Object.eval [as handleEvent] (EventEntryComponent.html:3)
    at handleEvent (eval at <anonymous> (bundle.js:132), <anonymous>:12120:138)
    at callWithDebugContext (eval at <anonymous> (bundle.js:132), <anonymous>:13412:42)
    at Object.debugHandleEvent [as handleEvent] (eval at <anonymous> (bundle.js:132), <anonymous>:13000:12)
    at dispatchEvent (eval at <anonymous> (bundle.js:132), <anonymous>:9020:21)
    at eval (eval at <anonymous> (bundle.js:132), <anonymous>:10948:20)
    at SafeSubscriber.schedulerFn [as _next] (eval at <anonymous> (bundle.js:132), <anonymous>:4069:36)
    at SafeSubscriber.__tryOrUnsub (eval at <anonymous> (bundle.js:87), <anonymous>:238:16)
    at SafeSubscriber.next (eval at <anonymous> (bundle.js:87), <anonymous>:185:22)
    at Subscriber._next (eval at <anonymous> (bundle.js:87), <anonymous>:125:26)
    at Subscriber.next (eval at <anonymous> (bundle.js:87), <anonymous>:89:18)
    at EventEmitter.Subject.next (eval at <anonymous> (bundle.js:151), <anonymous>:55:25)
    at EventEmitter.emit (eval at <anonymous> (bundle.js:132), <anonymous>:4043:76)
    at FormGroupDirective.onSubmit (eval at <anonymous> (bundle.js:434), <anonymous>:4859:23)
    at Object.eval [as handleEvent] (EventEntryComponent.html:3)
    at handleEvent (eval at <anonymous> (bundle.js:132), <anonymous>:12120:138)
    at callWithDebugContext (eval at <anonymous> (bundle.js:132), <anonymous>:13412:42)
    at Object.debugHandleEvent [as handleEvent] (eval at <anonymous> (bundle.js:132), <anonymous>:13000:12)
    at dispatchEvent (eval at <anonymous> (bundle.js:132), <anonymous>:9020:21)
    at eval (eval at <anonymous> (bundle.js:132), <anonymous>:9612:20)
    at HTMLFormElement.eval (eval at <anonymous> (bundle.js:441), <anonymous>:2735:53)
    at ZoneDelegate.invokeTask (eval at <anonymous> (bundle.js:4472), <anonymous>:424:31)
    at Object.onInvokeTask (eval at <anonymous> (bundle.js:132), <anonymous>:4346:37)
    at ZoneDelegate.invokeTask (eval at <anonymous> (bundle.js:4472), <anonymous>:423:36)
    at Zone.runTask (eval at <anonymous> (bundle.js:4472), <anonymous>:191:47)
    at HTMLFormElement.ZoneTask.invoke (eval at <anonymous> (bundle.js:4472), <anonymous>:486:38)

Any help would be appreciated.

Answer 1

Validate the function signature. Change

editEvent(eventId:number, event:Events){

to

editEvent(eventId:string, event:Events){

Answer 2

I found what the issue was. There was another method with the same name editEvent and having a different method signature. I did not notice it. That was a stupid mistake. Thanks for the help.