Parse .each() does not work within when() - javascript

Parse.Cloud.define("bulkUpdateUserViewedTraces", function(request, response){
Parse.Cloud.useMasterKey();
var userQuery = new Parse.Query(Parse.User);
userQuery.limit(200);
var userCount = 0;
userQuery
.find(function (users) {
var promises = _.map(users, function (user){
userCount++;
return populateViewedTraces(user);
});
return promises;
})
.then(function (promises) {
return Parse.Promise.when(promises);
})
.then(function(){
console.log("Processed " + userCount + " users");
response.success("Processed " + userCount + " users");
}, function(error){
console.error(JSON.stringify(error));
response.error(error);
});
});
function populateViewedTraces (user) {
var viewedTracesCount = 0;
var viewHistoryQuery = new Parse.Query("ViewHistory");
viewHistoryQuery.equalTo("user", user);
return viewHistoryQuery
.each(function (viewHistory) {
console.log("Got here");
viewedTracesCount++;
})
.then(function () {
console.log("Got here 2");
return user.save();
});
}
Doesnt work. Logs "Processed x users" but never logs "got here". The promises should execute during the when() call, but never do.
This makes absolutely no sense as every post I've seen describing when is written like this. For some reason this just doesnt do anything.

Related

Promise does not resolve node.js

I am trying to resolve some promises by the sendRequest function but it does not work.
For example, if I evoke sendRequest function 4 times, all of the times, I can see the log printed in the console and then going to resolve(data). But only 1 out of 4 times, the program reaches in to sendRequest.then().
Here is the complete code of that file.
change-name.js
var sendRequest = function(fileName){
return new Promise(function (resolve,reject) {
httpRequest(fileName).then(function (data) {
try{
if(.....){
if(.....){
var lastIndex = ....;}
if(.....){
var lastIndex = ....;}
str = fileName.substring(0, lastIndex);
if(.........){
sendRequest(str);}
else{
reject("this is the end");}
}
else{
console.log("end result" + JSON.stringify(data,null,4));
resolve(data);
//===== THIS RESOLVE DOES NOT WORK WHILE THE LOG PRINTS THE DATA =====//
}
}
catch(e){
resolve(data);
}
}).catch(function (err) {
reject(err);
});
});
};
server.js
this files calls the sendRequest function from the change-name.js and the then method is applied here for that function.
fs.readdir(path,(err,files)=>{
if(err){
console.log(err);
return;
}
for(i=0;i<files.length;i++){
sendRequest(files[i]).then(function (data) {
console.log(data + "\n");
}).catch(function(err){
console.log("end Error is " + err + "\n");
});
console.log(files);
}
});
The github link is "https://github.com/abhikulshrestha22/movierator".
Any help would be appreciated. Thanks
The problem is that one of your branches calls sendRequest again rather than resolving or rejecting, but then doesn't make any use of the promise the recursive call returns returns, so the promise you created for the outer call is never resolved. The inner one is (which is why you see the message in the console), but since nothing is using that promise, you don't get the result you expect.
There's also no need for new Promise in your code at all. httpRequest already gives you a promise, and your then handler on it creates a promise (if you return a value). So sendRequest should just return the result of calling then on httpRequest's promise, and within the then callback, either return the value to resolve the new promise with, or throw to reject. In the branch where you're calling sendRequest again, return the promise it returns; the one then creates will then resolve/reject based on that promise:
var sendRequest = function(fileName) {
return httpRequest(fileName).then(function(data) {
if (condition1) {
if (condition2) {
var lastIndex = something;
}
if (condition3) {
var lastIndex = somethingElse;
}
str = fileName.substring(0, lastIndex);
if (condition4) {
return sendRequest(str);
}
else {
throw new Error("this is the end");
}
}
else {
console.log("end result" + JSON.stringify(data, null, 4));
return data;
}
});
};
Here's a live example where httpRequest returns a random number 1-10, and if the number is less than 8, calls sendRequest again; it'll try up to three times before giving up:
function httpRequest() {
return new Promise(function(resolve) {
setTimeout(function() {
resolve(Math.floor(Math.random() * 10) + 1);
}, 500);
});
}
var sendRequest = function(fileName, retries) {
if (typeof retries !== "number") {
retries = 3;
}
return httpRequest(fileName).then(function(data) {
console.log("`then` got: " + data);
if (data > 7) {
console.log("It's > 7, yay! We're done");
return data;
}
console.log("It's <= 7g");
if (--retries === 0) {
console.log("Out of retries, rejecting");
throw new Error("out of retries");
}
console.log("retrying (" + retries + ")");
return sendRequest(fileName, retries);
});
};
document.getElementById("btn").addEventListener("click", function() {
var btn = this;
btn.disabled = true;
console.log("Sending request");
sendRequest("foo")
.then(function(data) {
console.log("Request complete: " + data);
})
.catch(function(err) {
console.log("Request failed: " + err);
// Because we don't throw here, it converts the rejection into a resolution...
})
.then(function() {
// ...which makes this kind of like a "finally"
btn.disabled = false;
});
}, false);
<input type="button" id="btn" value="Start">

Why isn't my promise getting resolved?

I have two functions - A helper function for downloading files which is as follows
var downloadHelper = function(url, saveDir) {
var deferred = Q.defer();
setTimeout(function() {
deferred.resolve("success");
}, 2000);
return deferred.promise;
}
Now I have a list of files to be downloaded in parallel. I have the logic for that function as follows:
var downloadAll = function() {
var fileDownloadList = []
for(var key in config.files) {
var deferred = Q.defer();
var saveLocation = __base + config.localDir
downloadHelper(
config.files[key],
saveLocation
).then(function() {
deferred.resolve("downloaded: " + fileUrl);
}).catch(function(err) {
deferred.reject(err);
});
fileDownloadList.push(deferred.promise);
}
Q.all(fileDownloadList).done(function() {
console.log("All downloaded");
},function(err) {
console.log(err);
});
setTimeout(function() {
console.log(fileDownloadList);
}, 10000);
}
The done is never getting called!
For debugging purposes, I added a setTimeout that will be called after 10 seconds and what I see is that out of 2 files, the second promise is resolved and the first one is still in pending state.
Any ideas?
Thanks in advance
One way to make your code work
for(var key in config.files) {
(function() {
var deferred = Q.defer();
var saveLocation = __base + config.localDir
downloadHelper(
config.files[key],
saveLocation
).then(function() {
deferred.resolve("downloaded: " + fileUrl);
}).catch(function(err) {
deferred.reject(err);
});
fileDownloadList.push(deferred.promise);
}());
}
But since downloadhelper returns a promise, no need to create yet another one
for (var key in config.files) {
var saveLocation = __base + config.localDir
fileDownloadList.push(downloadHelper(
config.files[key],
saveLocation
).then(function () {
return("downloaded: " + fileUrl);
}));
}
You'll see I removed
.catch(function(err) {
deferred.reject(err);
})
That's redundant, it's the same as not having the catch at all

Trying to get interval function to work with my factory

I create a factory where I put my http request for adding, retrieving and deleting tasks.
Now when I add a task you don't see the visual change. I have to refresh the browser. Now to fix this I figured I would write a function to check the length of the old array against the length of the new one and set an interval off 1 minutes on it to make this change and then pull in the tasks. I am able to log my length change of the array but nothing happens visually (still have to refresh the browser).
If anybody could help me out here.
Part of my app.js code:
global vars -> defaultStart, defaultEnd, clickDate
zazzleApp.factory('TaskService', function ($http) {
var TaskService = {};
TaskService.taskList = [];
TaskService.getTasks = function(cb){
$http.get('api/task/all')
.success(function(dataFromServer){
for (var i = 0; i < dataFromServer.length; i++) {
TaskService.taskList[i] = dataFromServer[i];
};
//console.log('LOGGING GET_TASK ', TaskService.taskList);
if(cb){
cb(dataFromServer);
}else{
return dataFromServer;
}
//return dataFromServer;
})
.error(function(errorFromServer){
//something went wrong, process the error here
console.log("Error in getting the users from the server ", errorFromServer);
})
};
TaskService.addTask = function(pTask){
var newClickDate = clickDate;
console.log('LOGGGING NEW CLICK DATE = ', newClickDate);
var newEditId = editId;
//console.log('LOGGGING NEW edit id = ', newEditId);
var url;
if (newEditId) {
url = 'api/task/update/' + newEditId;
} else {
url = 'api/task/create';
}
//console.log("URL URL USA", url, newEditId, newClickDate);
defaultStart = new Date(newClickDate);
defaultStart = defaultStart.getFullYear() + "-" + (defaultStart.getMonth() + 1) + "-" + defaultStart.getDate();
defaultStart += " 00:00:00";
defaultEnd = new Date(newClickDate).addDays(1);
defaultEnd = defaultEnd.getFullYear() + "-" + (defaultEnd.getMonth() + 1) + "-" + defaultEnd.getDate();
defaultEnd += " 00:00:00";
console.log('LOGGING DEFAULT START AND DEFAULT END ' , defaultStart, defaultEnd);
pTask.color = $('#containerColorPicker').attr('ng-data-id');
// returns makes sure the promis is returned from the server
return $http.post(url, {
'name': pTask.project_name,
'project_id': pTask.project_type,
'location_id': pTask.location,
'estimate_time': pTask.estimate_time || 2,
'project_client_name': pTask.project_client_name,
'url': pTask.url,
'resource_link': pTask.resource_link,
'notes': pTask.notes,
'start_time': pTask.start_time || defaultStart,
'end_time': pTask.end_time || defaultEnd,
/*'start_time': defaultStart,
'end_time': defaultEnd,*/
'color': pTask.color
}, {
headers: {
"Content-Type": "text/plain"
}
})
.success(function(data, status, headers, config) {
console.log(data);
TaskService.getTasks();
TaskService.taskList.push(data);//pushing the new task
//console.log("YYYYYYYYYYYYY -------->>>>>", defaultStart);
})
.error(function(data, status, headers, config) {
console.log("Failed to add the task to DB");
});
};
TaskService.deleteTask = function (){
var newEditId= editId;
$http.delete('api/task/delete/' + newEditId)
.success(function(dataFromServer){
console.log('logging edit id in delete taks func server ', newEditId);
var index;
for (var i = 0; i < TaskService.taskList.length; i++) {
if(TaskService.taskList[i]._id == newEditId){
//index = i;
console.log ("removing the element from the array, index: ", newEditId, i);
TaskService.taskList.splice(i,1);
}
};
/* if(editId !== -1){
console.log ("removing the element from the array, index: ", editId, index);
UserService.userList.splice(index,1);
}*/
console.log('TaskArray ', TaskService.taskList)
$('div[ng-data-id="'+ newEditId +'"]').remove();
})
.error(function(errorFromServer){
//something went wrong, process the error here
console.log("Error in deleting a user from the server");
})
};
return TaskService;
})
//START CONTROLLER
angular.module('zazzleToolPlannerApp')
.controller('CalendarCtrl', function ($scope, $mdDialog, $http, $rootScope, $timeout, User, Auth, UserService, TaskService) {
$scope.newTask = {};
$scope.newTask.project_name = "";
$scope.newTask.project_type = "";
$scope.newTask.location = "";
$scope.newTask.estimate_time = "";
$scope.newTask.project_client_name = "";
$scope.newTask.url = "";
$scope.newTask.resource_link = "";
$scope.newTask.notes = "";
$scope.newTask.color = "";
$scope.tasks = TaskService.taskList;
$scope.getTasksFromService = function () {
TaskService.getTasks(); //after this gets called, the data will be shown in the page automatically
}
$scope.getTasksFromService();
$scope.addTaskWithService = function () {
//note that you can process the promise right here (because of the return $http in the service)
TaskService.addTask($scope.newTask)
.success(function(data){
//here you can process the data or format it or do whatever you want with it
console.log("Controller: the task has been added");
$scope.tasks = [];// EMPTY THE ARRAY
$scope.tasks = TaskService.getTasks();
//console.log('Taskservice Controller ', $scope.updateGridDataAwesome);
})
.error(function(data){
//something went wrong
console.log("Controller: error in adding task");
});
}
$scope.deleteTaskWithService = function(){
TaskService.deleteTask();
}
TaskService.getTasks(function(data){
$scope.tasks = data;
});
var interval = setInterval(function(){
var oldLength = $scope.tasks.length;
TaskService.getTasks(function(data){
console.log('lengths', oldLength, data.length)
if(oldLength != data.length){
//$scope.tasks = data;
//TaskService.taskList.push(data);
$scope.tasks = TaskService.getTasks();
}
});
}, 6000)
This might be what you're looking for, by using $interval you can set an interval every x seconds:
$interval(function() {
// Something to be executed after 1min (60000ms)
}, 60000);
And then inject $interval into your factory:
zazzleApp.factory('TaskService', function ($http, $interval).....
Try this:
$http
.post("/api/pin", {})
.success(function(data) {
$scope.$apply(function() {
$scope.pins.push(data);
});
});
reference: https://stackoverflow.com/a/24836089/3330947
Update:
I did it like this:
Service (fetch all accounts):
.factory('accountService', function ($http) {
var accountObj = {
async: function () {
var promise = $http.get('account/').then(function (response) {
return response;
});
return promise;
}
};
return accountObj;
})
Controller:
//Call get accounts service and put all accounts in $scope.accounts
var getAccounts = function () {
accountService.async().then(function (d) {
$scope.accounts = d.data;}
}
//Create new account and update array of accounts
$scope.createAccount = function () {
$scope.data = {
'id' : 0,
'customerId' : $scope.outputCustomer[0].id,
'camsId' : $scope.outputCams[0].id,
'camsPin' : parseInt($scope.camsPin),
'username' : $scope.username,
'password' : $scope.password,
'email' : $scope.email,
'acfUsername' : $scope.acfUsername,
'accountActive' : $scope.accountActive,
'agentId' : $scope.outputAgent[0].id,
'freeswitchIds' : freeswitchIds
};
$http.post('account/save', $scope.data).success(
function (data, status) {
$scope.accounts.push(data);
}).error(function () {
});
};
My add function is in controller, i thin it can be redone to be service but this work soo
The problem may be in success of addTask. TaskService.getTaskis async. So the execute order will be: 1. http request in TaskService.getTasks 2. TaskService.taskList.push(data); 3. $http success callback.
.success(function(data, status, headers, config) {
console.log(data);
TaskService.getTasks();
TaskService.taskList.push(data);//pushing the new task
//console.log("YYYYYYYYYYYYY -------->>>>>", defaultStart);
})
In this order, step 2 is pointless. Because step 3 code may override TaskService.taskList
for (var i = 0; i < dataFromServer.length; i++) {
TaskService.taskList[i] = dataFromServer[i];
};
And another wrong place:
$scope.tasks = TaskService.getTasks();
this line code appears twice. But TaskService.getTasks() returns undefined because you don't put keyword return.
In addition, your practice to use promise is wrong. $http leverages promise specification. Don't use callback since you used promise. You may need read promise docs.

Parse cloud code - modifying all PFUsers

I'm trying to create a cloud Job that takes the users full name or username and saves it in lower case in another column. here's what I have so far:
Parse.Cloud.job('normaliseUsername',function(request, status) {
Parse.Cloud.useMasterKey();
var query = new Parse.Query(Parse.User);
query.find({
success: function(items){
for (var i=0;i<items.length;i++) {
var user = items[i];
console.log(user);
var changed = user["nameChanged"];
if (changed === true) {
var username = user.username;
user.set("lowerCaseName",username.toLowerCase());
} else {
var realName = user["firstName"] + " " + user["lastName"];
user.set("lowerCaseName",realName.toLowerCase());
}
user.save();
}
}
});
});
This results in a new column, lowerCaseName, full of undefined.
how do I access properties of a PFUser in this instance? I have tried using user.get(''); but it says Cannot call method 'get' of undefined
Do it this way :
Parse.Cloud.job("normaliseUsername", function(request, status) {
Parse.Cloud.useMasterKey();
var count_user = 0;
var query = new Parse.Query(Parse.User);
query.descending('updatedAt');
query.Exist('nameChanged');
query.limit(1000);
return query.find().then(function(users) {
return Parse.Promise.when(users.map(function(user) {
count_user+= 1;
if (user.get("nameChanged")) {
user.set("canonical_firstname", user.get("username").toLowerCase());
} else {
var realName = user.get("firstname") + ' ' + user.get("lastname");
user.set("lowerCaseName", realName.toLowerCase());
}
return user.save();
}));
}).then(function() {
status.success("normaliseUsername with " + count_user + " user(s) updated.");
}, function(error) {
status.error("Uh oh, something went wrong.");
});
});
Your loop with for, will never works, you need to use Promise. More information here : http://blog.parse.com/learn/engineering/whats-so-great-about-javascript-promises/
The way the above script works, you will work with Promise in Parallel, not in Series : https://parse.com/docs/js/guide#promises

i var undefined inside a for loop

//Server Functions
var socketArray = [];
var socketRcon = [];
for (var i = 0; i < serversConfig.serversArray.length; i++) {
socketArray[i] = new Socket;
socketArray[i].setEncoding("utf8");
socketArray[i].setNoDelay();
socketArray[i].setTimeout(1000);
socketArray[i].connect(serversConfig.serversArray[i].port, serversConfig.serversArray[i].ip);
socketRcon[i] = serversConfig.serversArray[i].rcon;
socketArray[i].on("connect", function() {
this.write(socketRcon[i] + "\n", "utf8");
console.log("CONNECTED TO THE SERVER...");
});
socketArray[i].on("data", function(data) {
console.log(data);
});
socketArray[i].on("error", function(err) {
console.log("ERROR:" + err);
});
socketArray[i].on("close", function(err) {
console.log("CLOSED:" + err);
});
};
This is the code I have now to connect to multiple servers from a config file, and I need that each time the socket connects, I need to send a password to it. But 'socketRcon[i]' is undefined, why is that happening and how do i fix it?
Because by the time that code is run, i is equal to serversConfig.serversArray.length, meaning socketRcon[i] is undefined.
Anchor your value:
for( var i=0; i<l; i++) (function(i) {
// do stuff here
})(i);
You could also just do:
serversConfig.serversArray.forEach(function(srvconfig) {
var sock = new Socket();
sock.setEncoding("utf8");
sock.setNoDelay();
sock.setTimeout(1000);
socketArray.push(sock);
socketRcon.push(srvconfig.rcon);
sock.on("connect", function() {
this.write(srvconfig.rcon + "\n", "utf8");
console.log("CONNECTED TO THE SERVER...");
});
sock.on("data", function(data) {
console.log(data);
});
sock.on("error", function(err) {
console.log("ERROR:" + err);
});
sock.on("close", function(err) {
console.log("CLOSED:" + err);
});
sock.connect(srvconfig.port, srvconfig.ip);
});

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