Aborting query use case

[JeromeDeLeon]

I followed the test case reference to the new feature query.cancel for aborting the request made by @dplewis . I don't know if that was the right thing. After that didn't work, here's what I tried:

query.find().then(console.log).catch(console.error)
setTimeout(() => {
    query.cancel();
}, 0);

I saw from the network section that the query was cancelled however, two request were made (one that got cancelled and one that went successfully) and I also saw from the console that it passes the then block from above. So how do I use the cancel? awaiting before calling abort was nonsense because the request was already completed before aborting.

I thought doing below snippet is possible:

query.find().then(console.log).catch(console.error)
query.cancel();

[dplewis]

Sorry about that I haven't updated the documentation for that yet.

The cancel query is tricky and could use improvement.

https://github.com/parse-community/Parse-SDK-JS/blob/master/src/ParseQuery.js#L1849

There is an on change event for the event task that you can subscribe to so that you can know when the query has started. I think an improvement should be made to determine when to set the requestTask

query._xhrRequest.onchange = () => {
  query.cancel();
};
query.find().then(console.log).catch(console.error)

[JeromeDeLeon]

It's fine. I just want to try this out since I've been waiting for this 👍 .

Is it not possible to move the onchange inside cancel? so it automatically listen to on change when calling cancel?

[dplewis]

I think that would work. Can you try it out?

[JeromeDeLeon]

I tried your snippet but it didn't work and the request was still successful.

[JeromeDeLeon]

I also tried doing it in ReactJS but no luck:

componentDidMount() {
    // setup my query
    this.query = query;
    this.query.find().then(console.log)
}

componentWillUnmount() {
    this.query.cancel();
}

[dplewis]

@JeromeDeLeon I think it might be related to where we set the request task.

https://github.com/parse-community/Parse-SDK-JS/blob/master/src/RESTController.js#L110

Can you try to move it after xhr.send()?

[JeromeDeLeon]

I tried forking the lib but failed to run when I installed it using npm install github... saying that no such file or directory for /node_modules/parse/lib/browser/ObjectStateMutations.js