README.md

ApolloRxObservable

Here's an implementation of QueryObservable that works with RxJS.

---

import { Observable } from 'rxjs/Observable';
import 'rxjs/add/observable/from';

const origin = client.watchQuery(options); // QueryObservable
const obs = Observable.from(origin);

origin.refetch(); // works
obs.refetch(); // refetch is undefined
obs.ish.refetch(); // works (it should) because `ish` is a reference to `origin`

To solve that problem I created a custom observable called ApolloRxObservable that extends Observable from RxJS.

QueryObservable is saved under apollo property. This way I could create methods like refetch(), startPolling(), stopPolling(). Every method uses ApolloRxObservable.apollo to call specific method.

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import 'rxjs';
import { ApolloRxObservable } from 'apollo-rx-observable';

const origin = client.watchQuery(options); // QueryObservable
const obs = new ApolloRxObservable(origin);

origin.refetch(); // works
obs.refetch(); // works

obs.map(customMapFunction).refetch() // refetch is undefined

As you can see, it still won't work with operators. Here's why.

Every operator uses Observable.lift() method, for example map().

Observable.lift() creates new Observable, then assigns the current observable under source property. Here the moment where our custom methods (refetch etc) are being dropped.

I solved this by overwriting lift() method.

Now, the lift() method creates a new instance of ApolloRxObservable instead of Observable, and passes the QueryObservable from apollo property in the constructor.

Every operator returns now ApolloRxObservable.

import 'rxjs';
import { ApolloRxObservable } from 'apollo-rx-observable';

const origin = client.watchQuery(options); // QueryObservable
const obs = new ApolloRxObservable(origin);

origin.refetch(); // works
obs.refetch(); // works

obs.map(customMapFunction).refetch() // works

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Problem with subscribe method

An example

import 'rxjs';
import { ApolloRxObservable } from 'apollo-rx-observable';

const origin = client.watchQuery(options); // QueryObservable
const obs = new ApolloRxObservable(origin);

obs.subscribe() // an error

It happens because there is no _subscription method inside the ApolloRxObservable.

Even if we add one, we still need to subscibe to the QueryObservable (this.apollo).

I solved this here.

So now we can subscribe to an Observable at any point.

import 'rxjs';
import { ApolloRxObservable } from 'apollo-rx-observable';

const origin = client.watchQuery(options); // QueryObservable
const obs = new ApolloRxObservable(origin);

obs.map(result => result.data).subscribe(data => this.data = data);