I am trying to implement the advanced push targeting from cloud code (background job) using parse.com service. I have added the day as a field in the Installation object.
I made it work if I have only one condition, i.e. day equals 1, using following snippet
var pushQuery = new Parse.Query(Parse.Installation);
pushQuery.equalTo("day",1);
Parse.Push.send({
where: pushQuery,
data: {
"content-available" : "1",
alert : "Message day 1!",
sound : "default"
}}, {
success: function() {
// Push was successful
},
error: function(error) {
// Handle error
}}).then(function() {
// Set the job's success status
status.success("Job finished successfully.");
}, function(error) {
// Set the job's error status
status.error("Uh oh, something went wrong.");
});
Reference: Push Notification Java Script guide
My next step is sending notifications to 20 queries (0 <= day < 20) and for each query send message according to day number. Calling function 20 times seems to me ugly, may I anyhow iterate, calling each time in loop Parse.Push.send function?
I solved my problem using Parse.Promise.when(promises)
Promises are a little bit magical, in that they let you chain them without nesting. If a callback for a promise returns a new promise, then the first one will not be resolved until the second one is. This lets you perform multiple actions without incurring the pyramid code you would get with callbacks.
function scheduleWordsForDay(day)
{
var pushQuery = new Parse.Query(Parse.Installation);
pushQuery.equalTo("day",day);
pushQuery.exists("deviceToken");
var promise = new Parse.Promise();
Parse.Push.send({
where: pushQuery,
data: {
alert : "word" + day
}}, { success: function() {
// Push was successful
},
error: function(error) {
}}).then (function(result){
//Marks this promise as fulfilled,
//firing any callbacks waiting on it.
promise.resolve(result);
}, function(error) {
//Marks this promise as fulfilled,
//firing any callbacks waiting on it.
promise.reject(error);
});
return promise;
}
Parse.Cloud.job("scheduleWordNotification", function(request, status)
{
var promiseArray = [];
for (var i = 0; i < 100; i++) {
var promise = scheduleWordsForDay(i);
promiseArray.push(promise);
}
//Returns a new promise that is
//fulfilled when all of the input promises are resolved.
Parse.Promise.when(promiseArray).then(function(result) {
console.log("success promise!!")
status.success("success promise!!");
}, function(error) {
console.error("Promise Error: " + error.message);
status.error(error);
});
});
Related
I make Ajax requests with a Promise and usually handle errors the same way. So e.g. if a 404 happens, then I would just display a standard error message by default. But in some cases I want to do something else.
Note: I'm using ExtJS 4 to do the actual Ajax request, but this issue is not specific to ExtJS. ExtJS does not use Promises, so I'm basically converting their API to a Promise API.
This is the code:
var defaultErrorHandler = function(response) {
// do some default stuff like displaying an error message
};
var ajaxRequest = function(config) {
return new Promise(function(fulfill, reject) {
var ajaxCfg = Ext.apply({}, {
success: function(response) {
var data = Ext.decode(response.responseText);
if (data.success) {
fulfill(data);
} else {
defaultErrorHandler(response);
reject(response);
}
},
failure: function(response) {
defaultErrorHandler(response);
reject(response);
}
}, config);
Ext.Ajax.request(ajaxCfg);
});
};
// usage without special error handling:
ajaxRequest({url: '/some/request.json'}).then(function(data) {
// do something
});
// usage with special error handling:
ajaxRequest({url: '/some/request.json'}).then(function(data) {
// do something
}, function(response) {
// do some additional error handling
});
Now the problem: The "usage without special error handling" does not work, because if I do not provide a reject function, it will throw an error. To fix this, I am forced to provide an empty function, like so:
// usage without special error handling:
ajaxRequest({url: '/some/request.json'}).then(function(data) {
// do something
}, function() {});
Having to provide an empty function every time (and in my code base this will be hundreds of times) is ugly, so I was hoping there was a more elegant solution.
I also do not want to use catch() since that would catch ALL errors thrown, even if it happens in the fulfill function. But actual errors happening in my code should not be handled, they should appear in the console.
There is no such thing a "default error handler for all promises", unless you are looking to provide an unhandled rejection handler. That would however not be restricted to the promises for your ajax requests.
The simplest and best solution would be to just expose your defaultErrorHandler and have every caller explicitly pass it the then invocation on your promise. If they don't want to use it, they either need to provide their own special error handler or they will get a rejected promise. This solution provides maximum flexibility, such as allowing to handle the rejection further down the chain.
If that is not what you want to do, but instead require immediate handling of the ajax error, your best bet is to override the then method of your returned promises:
function defaultingThen(onfulfill, onreject = defaultErrorHandler) {
return Promise.prototype.then.call(this, onfulfill, onreject);
}
function ajaxRequest(config) {
return Object.assign(new Promise(function(resolve, reject) {
Ext.Ajax.request({
...config,
success: function(response) {
var data = Ext.decode(response.responseText);
if (data.success) {
resolve(data);
} else {
reject(response);
}
},
failure: reject,
});
}), {
then: defaultingThen,
});
}
I’m having an issue with my project. In my angularjs controller a function is being executed and then my function to make a call to my database to update a record is executing without waiting for the first function to complete and therefore sending over an undefined result variable.
Below you can find my code snippets with my attempts so far.
Submit button function:
$scope.submitNewStarters = function () {
// result is returning as undefined <<<<< Issue
var result = $scope.sendNewStarterDetailsToApi();
$scope.updateArchivedImportFlag(result);
};
Controller function handling the logic:
$scope.sendNewStarterDetailsToApi = function () {
swal({
title: "Confirmation",
text: "Are you sure you want to import the new starter details?",
icon: "info",
dangerMode: true,
buttons: ["No", "Yes"]
}).then(function (approve) {
if (approve) {
// Get each of the new starter details that have been set to true for import.
var newStartsToImport = $scope.tableParams.data.filter(x => x.imported == true);
for (let i = 0; i < newStartsToImport.length; i++) {
// Parses the current new starter object into a stringified object to be sent to the api.
$scope.newStartsToImport = $scope.createApiObject(newStartsToImport[i]);
// A check to ensure that nothing has went wrong and that the stringify object has worked.
if ($scope.newStartsToImport !== "") {
apiFactory.postNewStarterDetailsToApi($scope.newStartsToImport).then(function (response) {
var isSuccessful = response.data.d.WasSuccessful;
if (isSuccessful)
toastr.success("New starter details successfully sent to API.", "Success!");
else {
var errorMessage = response.data.d.ErrorMessage;
toastr.error("New starter details were unsuccessfully sent to API. Please try again. \n" + errorMessage, "Error!");
}
});
}
else {
toastr("An error has occurred when attempting to create the data object to be sent to API. The process has stopped!", "Error!");
break;
}
}
return newStartsToImport;
}
else
toastr.info("No new starter details were sent to API", "Information!");
});
};
Factory function for API call:
postNewStarterDetailsToApi: function (data) {
return $http({
url: "https://www.example.com/services/service.svc/Import",
method: "POST",
data: data,
headers: {
'Content-Type': 'application/json; charset=utf-8',
}
}).then(function successCallbwack(response) {
// this callback will be called asynchronously
// when the response is available
return response;
}, function errorCallback(response) {
// called asynchronously if an error occurs
// or server returns response with an error status.
console.log('An error has occured during the function call postNewStarterDetailsToApi(): ', response);
});
}
So with the concept of promises how am I able to execute the sendNewStarterDetailsToApi function, wait for it to complete and then return the populated array? Once the populated array (result) is returned then execute the updateArchivedImportFlag function.
Below I've added an illustration of what I'd like to achieve:
The approach I am using is , save all the promises in an array .
Use any promise library or es6 Promise, and use .all function to wait for all promises to execute
The syntax i wrote is not totally correct. Since you are using angular js , you can use $q.all
$scope.sendNewStarterDetailsToApi = function () {
swal({
title: "Confirmation",
text: "Are you sure you want to import the new starter details?",
icon: "info",
dangerMode: true,
buttons: ["No", "Yes"]
}).then(function (approve) {
var res = [];
if (approve) {
// Get each of the new starter details that have been set to true for import.
var newStartsToImport = $scope.tableParams.data.filter(x => x.imported == true);
for (let i = 0; i < newStartsToImport.length; i++) {
// Parses the current new starter object into a stringified object to be sent to the api.
$scope.newStartsToImport = $scope.createApiObject(newStartsToImport[i]);
// A check to ensure that nothing has went wrong and that the stringify object has worked.
if ($scope.newStartsToImport !== "") {
res.push(apiFactory.postNewStarterDetailsToApi($scope.newStartsToImport))
}
else {
toastr("An error has occurred when attempting to create the data object to be sent to API. The process has stopped!", "Error!");
break;
}
}
return Promise.all(res);
}
else
toastr.info("No new starter details were sent to API", "Information!");
}).then(function (data) {
data.forEach((response) => {
var isSuccessful = response.data.d.WasSuccessful;
if (isSuccessful)
toastr.success("New starter details successfully sent to API.", "Success!");
else {
var errorMessage = response.data.d.ErrorMessage;
toastr.error("New starter details were unsuccessfully sent to API. Please try again. \n" + errorMessage, "Error!");
}
})
}).then((res) => {
//call Submit new starters
})
};
I'm using promise but sometimes I can't get JSON from various reason in one case, how can I fire up done even if some of JSON is missing, with this code at the moment I'm having only failed message
$.when(
arrayResults[0] ? $.getJSON("url") : null,
arrayResults[1] ? $.getJSON("url") : null,
arrayResults[2] ? $.getJSON("url") : null
).done(function () { }).fail(function () {
console.log('Failed');
});
You can use deferred.always(cb):
$.when(
arrayResults[0] ? $.getJSON("url") : null,
arrayResults[1] ? $.getJSON("url") : null,
arrayResults[2] ? $.getJSON("url") : null
)
.done(function () { console.log('I will run when the promise was resolved') })
.fail(function () { console.log('I will run when the promise was rejected') })
.always(function() { console.log('I will always fire, regardless of previous results') })
See further information here: https://api.jquery.com/deferred.always/
If you are using jQuery v3+ it is Promises A+ compliant so you can add catch() to the request promise
Whenever you return from within a catch it resolves the prior promise and passes whatever you return to the next then() in the promise chain
function getData(url){
return $.getJSON(url)
.then(data=>data)
.catch(resolveFailure)
}
function resolveFailure(jqXhr) {
// return whatever you want here. I added the status in case that is of interest
// could return `false` or string or whatever
// can also log any issues back to server if needed
return {
error: true,
status: jqXhr.status,
statusText: jqXhr.statusText
};
}
var req = getData('https://api.myjson.com/bins/l9ywp'),
req2 = getData('https://httpbin.org/FAIL'),
req3 = getData('https://api.myjson.com/bins/l9ywp');
// could also replace `$.when with `Promise.all()`
$.when(req, req2, req3).then(function(r1, r2, r3) {
// validate the arguments based on whatever you return in the catch()
console.log('r1', r1);
console.log('r2', r2);// object returned from catch()
console.log('r3', r3);
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
Tried loads of different variations with my cloud code and I can't get it to work. Basically I've got a push notification function, and in this function I want to add an object to a PFUser's array, but you can't use a master key in Xcode so here's what I have:
Parse.Cloud.define("iOSPush", function (request, response) {
console.log("Inside iOSPush");
var data = request.params.data;
var not_class = request.params.not_class;
var not_objectid = request.params.not_objectid;
var not_date = request.params.not_date;
var userid = request.params.userid;
var recipientUser = new Parse.Query(Parse.User);
recipientUser.equalTo("objectId", userid);
// set installation query:
var pushQuery = new Parse.Query(Parse.Installation);
pushQuery.equalTo('deviceType', 'ios');
pushQuery.matchesQuery('user', recipientUser);
pushQuery.find({ useMasterKey: true }).then(function(object) {
response.success(object);
console.log("pushQuery got " + object.length);
}, function(error) {
response.error(error);
console.error("pushQuery find failed. error = " + error.message);
});
// send push notification query:
Parse.Push.send({
where: pushQuery,
data: data
}, { useMasterKey: true }).then(function() {
console.log("### push sent!");
// create notification:
var notification = {
"title": not_class,
"body": request.params.data.alert,
"class": not_class,
"objectId": not_objectid,
"date": not_date
};
// get notifications:
var tmp_notifications = recipientUser.get("notifications");
// add notification:
tmp_notifications.push(notification);
// update with notifications:
recipientUser.set("notifications", tmp_notifications);
recipientUser.save();
}, function(error) {
console.error("### push error" + error.message);
});
response.success('success. end of iospush');
});
The Xcode cloud function I have provides the correct information, the function gets to the end.. just the function is not setting the notifications for some reason
I ended up figuring out the answer to this post myself. The reason this didn't work is because I needed to first fetch the user object in a separate query, then save it using the master key. I also found out that there's a function for appending data onto an existing array without having to create another one (parseObject.add()):
var userQ = new Parse.Query(Parse.User);
userQ.get(userid, {
success: function(theuser) {
console.log("### got userrrrrrrrrr!");
theuser.add("notifications", n_object);
theuser.save(null, {useMasterKey:true});
},
error: function(object, error) {
// The object was not retrieved successfully.
// error is a Parse.Error with an error code and message.
}
});
This set of code was executed just before:
response.success('success. end of iospush');
I've just started using bluebird promises and am getting a confusing error
Code Abstract
var
jQueryPostJSON = function jQueryPostJSON(url, data) {
return Promise.resolve(
jQuery.ajax({
contentType: "application/json; charset=utf-8",
dataType: "json",
type: "POST",
url: url,
data: JSON.stringify(data)
})
).then(function(responseData) {
console.log("jQueryPostJSON response " + JSON.stringify(responseData, null, 2));
return responseData;
});
},
completeTask = function completeTask(task, variables) {
console.log("completeTask called for taskId: "+task.id);
//FIXME reform variables according to REST API docs
var variables = {
"action" : "complete",
"variables" : []
};
spin.start();
return jQueryPostJSON(hostUrl + 'service/runtime/tasks/'+task.id, variables)
.then(function() {
gwl.grrr({
msg: "Completed Task. Definition Key: " + task.taskDefinitionKey,
type: "success",
displaySec: 3
});
spin.stop();
return null;
});
}
The jQueryPostJSON function seems to work fine as is when used else where, but in that case there is data returned from the server.
When it's used within complete task, the POST is successful as can be seen on the server side, but the then function is never called instead in the console I get the error
completeTask called for taskId: 102552
bundle.js:20945 spin target: [object HTMLDivElement]
bundle.js:20968 spinner started
bundle.js:1403 Warning: a promise was created in a handler but was not returned from it
at jQueryPostJSON (http://localhost:9000/dist/bundle.js:20648:22)
at Object.completeTask (http://localhost:9000/dist/bundle.js:20743:14)
at http://localhost:9000/dist/bundle.js:21051:15
From previous event:
at HTMLDocument.<anonymous> (http://localhost:9000/dist/bundle.js:21050:10)
at HTMLDocument.handleObj.handler (http://localhost:9000/dist/bundle.js:5892:30)
at HTMLDocument.jQuery.event.dispatch (http://localhost:9000/dist/bundle.js:10341:9)
at HTMLDocument.elemData.handle (http://localhost:9000/dist/bundle.js:10027:28)
bundle.js:1403 Unhandled rejection (<{"readyState":4,"responseText":"","sta...>, no stack trace)
The warning I get the reason for, that's not the issue.
It's the Unhandled rejection and the fact that there was in fact no error from the POST.
line 21050 is here I am testing the combination of these to functions from separate modules
jQuery(document).bind('keydown', 'ctrl+]', function() {
console.log("test key pressed");
api.getCurrentProcessInstanceTask()
.then(function(task) {
api.completeTask(task);
});
});
Output from the first function call api.getCurrentProcessInstanceTask() seems to indicate it is working correctly, but here it is anyway
getCurrentProcessInstanceTask = function getCurrentProcessInstanceTask() {
if (!currentProcess || !currentProcess.id) {
return Promise.reject(new Error("no currentProcess is set, cannot get active task"));
}
var processInstanceId = currentProcess.id;
return Promise.resolve(jQuery.get(hostUrl + "service/runtime/tasks", {
processInstanceId: processInstanceId
}))
.then(function(data) {
console.log("response: " + JSON.stringify(data, null, 2));
currentProcess.tasks = data.data;
// if(data.data.length > 1){
// throw new Error("getCurrentProcessInstanceTask expects single task result. Result listed "+data.data.length+" tasks!");
// }
console.log("returning task id: "+data.data[0].id);
return data.data[0];
});
},
You're getting the warning because you are - as it says - not returning the promise from the then handler.
Where the rejection is coming from would best be tracked by catching it and logging it. That there is no stack trace suggests that you (or one of the libs you use) is throwing a plain object that is not an Error. Try finding and fixing that.
Your call should look like this:
api.getCurrentProcessInstanceTask().then(function(task) {
return api.completeTask(task);
// ^^^^^^
}).catch(function(err) {
// ^^^^^
console.error(err);
});