Parse.Push.send success probably called too soon - parse-platform

Question

I'm trying to implement one time PUSH notification subscriptions in the Parse Cloud service. Here's my model:
Installation.user - pointer to User
User - team (String)
Subscription - email (String), status (String), user (pointer to User)
As a user, I can say - send PUSH notification(s), to all my devices, when user with email became status and this user is in my team. User can have many subscriptions. User can unsubscribe manually (via OS X, iOS, Android, ... apps) or automatically - when user receives PUSH notification, subscription should be automatically cancelled. He can subscribe again, no problem, but auto cancellation is a must. These subscriptions are user based, user can see them on devices.
I wrote Parse Cloud function which consists of two pieces.
Send PUSH
Parse.Push.send({
where : query,
data : pushData
},
{ success: function() {
response.success('OK');
}, error: function(err) {
console.log(err);
response.error({ error: err });
}});
This does work. My query works and PUSH received.
Delete Subscriptions
deleteSubscriptionQuery.find({
success: function(objects) {
Parse.Object.destroyAll(objects, {
success: function() {
response.success('OK');
},
error: function(err) {
console.log(err);
response.error(err);
}
});
},
error: function(err) {
console.log(err);
response.error(err);
},
});
This does work. My deleteSubscriptionQuery works and correct subscriptions deleted.
Combined Together
Parse.Push.send({
where : query,
data : pushData
},
{ success: function() {
deleteSubscriptionQuery.find({
success: function(objects) {
Parse.Object.destroyAll(objects, {
success: function() {
response.success('OK');
},
error: function(err) {
console.log(err);
response.error(err);
}
});
},
error: function(err) {
console.log(err);
response.error(err);
},
});
}, error: function(err) {
console.log(err);
response.error({ error: err });
}});
This doesn't work and success is reported. It seems that the problem lies in Parse.Push.send, ie. success is called too soon. I assume Parse.Push.send doesn't really send notifications, but just schedules them and success is called upon successful schedule. If so, should be renamed to Parse.Push.schedule. Also I assume that they are scheduled with my query (query saved, not really executed), so, I suspect this solution doesn't work because of:
Parse.Push.send - saves my query and calls success,
Subscription objects are deleted in success,
Parse started to process my pushes with saved query, executes the query and it returns zero objects, because I already deleted Subscription objects in success of Parse.Push.send.
Am I right? Does anyone know Parse internals? If I am right, what do you propose I should do to implement one time PUSH notifications based on custom queries?

Answer 1

Here's the solution based on #Wain's proposal.
Fetch Subscription objects based on request parameters.
User is included in this query, so, it's fetched along with Subscription objects.
Make separate Installation query based on User objects from Subscription objects.
Send PUSH to separate Installation query.
Delete already fetched Subscription objects upon success.
I can safely delete Subscription objects in this way and it doesn't interfere with Installation query for PUSH notifications. Does work as expected.
Parse.Cloud.define("status", function(request, response) {
//
// Input validation
//
if (!request.params.hasOwnProperty("status")) {
response.error("Missing status parameter");
return;
}
var statusQuo = request.params["status"]
if (!statusQuo.hasOwnProperty("email") || !statusQuo.hasOwnProperty("team") || !statusQuo.hasOwnProperty("status")) {
response.error("Invalid status dictionary");
return;
}
var status = statusQuo["status"]
if ( status != "Available" ) {
response.success('OK');
return;
}
var email = statusQuo["email"]
var team = statusQuo["team"]
Parse.Cloud.useMasterKey();
//
// Find subscriptions
//
var usersQuery = new Parse.Query(Parse.User);
usersQuery.equalTo('team', team);
var Subscription = Parse.Object.extend("Subscription");
var subscriptionsQuery = new Parse.Query(Subscription);
subscriptionsQuery.include('user');
subscriptionsQuery.equalTo('status', status);
subscriptionsQuery.equalTo('email', email);
subscriptionsQuery.matchesQuery('user', usersQuery);
subscriptionsQuery.find({
success: function(subscriptions) {
var users = subscriptions.map(function(subscription) {
return subscription.get('user');
});
//
// Query for notifications / installations
//
var query = new Parse.Query(Parse.Installation);
query.equalTo('channels', 'status');
query.containedIn('user', users);
//
// Push notifications data
//
var pushData = { 'status' : statusQuo };
var apsData = { 'sound' : '', 'alert' : email + ' became Available.' };
pushData['aps'] = apsData
Parse.Push.send({
where : query,
data : pushData
},
{ success: function() {
Parse.Object.destroyAll(subscriptions, {
success: function() {
response.success('OK');
},
error: function(err) {
console.log(err);
response.error(err);
}
});
}, error: function(err) {
console.log(err);
response.error({ error: err });
}});
}, error: function(err) {
console.log(err);
response.error(err);
}
});
});