Parse cloudcode beforeSave obtain pre-updated object - javascript

In a beforeSave hook I want to obtain the state of the object prior to the update. In this particular case it is to stop a user from changing their choice once they have made it. Pseudo-code looks something like:
If (user has already voted) {
deny;
} else {
accept;
}
And the code that I have so far is:
Parse.Cloud.beforeSave('votes', function(request, response) {
if (!request.object.isNew()) {
// This is an update. See if the user already voted
if (request.object.get('choice') !== null) {
response.error('Not allowed to change your choice once submitted');
}
}
response.success();
}
But request.object is the state of the object with the update already applied.
Note that the 'votes' object is created separately so this isn't allowing an insert but not an update will not suffice; I need to know if a given field is already set in the database.

While Krodmannix's response is correct (and was helpful to me) it has the overhead of a full query. If you are doing things in beforeSave, you really want to streamline them. As a result, I believe a fetch command is much preferable.
Parse.Cloud.beforeSave('votes', function(request, response) {
if (!request.object.isNew()) {
var Votes = Parse.Object.extend("votes");
var oldVote = new Votes();
oldVote.set("objectId",request.object.id);
oldVote.fetch({
success: function(oldVote) {
if (oldVote('choice') !== null) {
response.error('Not allowed to change your choice once submitted');
}
else {
response.success(); // Only after we check for error do we call success
}
},
error: function(oldVote, error) {
response.error(error.message);
}
});
});

If you are using the self hosted Parse Server, there is a property on request called "original" that is the object before changes.
Parse.Cloud.beforeSave("Post", function(request, response) {
console.log(request.object); //contains changes
console.log(request.original); //contains original
response.success();
});

You can use Parse DirtyKeys to identify which field has changed.
Parse.Cloud.beforeSave(Parse.User, function(request, response) {
for (dirtyKey in request.object.dirtyKeys()) {
if (dirtyKey === "yourfieldname") {
response.error("User is not allowed to modify " + dirtyKey);
return;
}
}
response.success();
});

The request variable is the updated row itself. You can get it's object id through request.object.idand use this to grab the current row from the database and check the current value, like so:
Parse.Cloud.beforeSave('votes', function(request, response) {
if (!request.object.isNew()) {
var query = new Parse.Query("votes");
query.get(request.object.id, { // Gets row you're trying to update
success: function(row) {
if (row.get('choice') !== null)
response.error('Not allowed to change your choice once submitted');
response.success(); // Only after we check for error do we call success
},
error: function(row, error) {
response.error(error.message);
}
});
}

This Worked :
var dirtyKeys = request.object.dirtyKeys();
var query = new Parse.Query("Question");
var clonedData = null;
query.equalTo("objectId", request.object.id);
query.find().then(function(data){
var clonedPatch = request.object.toJSON();
clonedData = data[0];
clonedData = clonedData.toJSON();
console.log("this is the data : ", clonedData, clonedPatch, dirtyKeys);
response.success();
}).then(null, function(err){
console.log("the error is : ", err);
});

Related

AJAX response error: net::ERR_EMPTY_RESPONSE

CODE:
FRONT-END
$(document).ready(function(){
$('.delete-post').on('click', function(){
var id = $(this).data('id');
var section = $(this).data('section');
var url = '/users/delete/'+id;
if(confirm("Delete Post ?")){
$.ajax({
url: url,
type:'DELETE',
success: function(result){
console.log('Deleting post...');
window.location.href='/users/profile';
},
error: function(err){
console.log(err);
}
});
}
});
});
BACK-END:
router.delete('/delete/:id', function(req, res, next) {
var id = req.params.id;
var section = req.params.section;
var image = "";
var author = "";
var postRef = firebase.database().ref("posts/"+section+"/"+id);
var userRef = firebase.database().ref("users/posts/"+id);
var likesRef = firebase.database().ref("users/likes/"+id);
var hotRef = firebase.database().ref("hot/"+section+"/"+id);
postRef.once('value', function(snapshot){
image = snapshot.image;
author = snapshot.author;
if (firebase.auth().currentUser.uid.toString() == author) {
var file = bucket.file(image);
file.delete(function (err, apiResponse) {
if (err) {
console.log(err);
}
else {
console.log("Deleted successfully");
postRef.remove();
userRef.remove();
hotRef.remove();
likesRef.remove();
req.flash('success_msg','Post Deleted');
res.send(200);
}
});
}
});
});
SITUATION:
I added delete buttons so the user could delete his posts.
When the user clicks the button an AJAX request is made to my Node.js server.
But I get the following error:
ERROR:
net::ERR_EMPTY_RESPONSE
QUESTION:
What is this error and how do I fix it ?
The response you're getting is actually correct. Per the docs, Firebase returns a 200 status code and an empty response. net::ERR_EMPTY_RESPONSE is exactly that. What you should do is check for both null and a 200 status code in the response; if true, you can safely assume that the post was deleted.
My personal opinion is that Firebase should really consider returning something more substantial than nothing and a generic, catch-all status code. I'd prefer something like 204 No Content, or 410 Gone. But, alas.
—
Side note: this conditional will never return anything if the post doesn't belong to the author — your API should still return something (an error, probably in this case) even if your conditional doesn't match. Like:
if (firebase.auth().currentUser.uid.toString() == author) {
// your code
} else {
res.status(401).send("User does not have permission to complete the operation.")
}

How to chain functions in Parse CloudCode?

I've done a parse job that checks every "X" time if "emailSent" is false, for each user. If it is, I call a function to send a email and change the "emailSent" to true. That works.
My problem is with the function "getMaxId". I need to return the maxid value to change each user "id_client" column, but I don't know how. I've tried this but it doesn't work. This is writing nothing: "console.log("Write somethingggg"); "
Here is the code...
Parse.Cloud.job("test", function(request, status) {
// Set up to modify user data
Parse.Cloud.useMasterKey();
var texto = "New verified emails:\n\t";
// Query for all users
var query = new Parse.Query(Parse.User);
//query.equalTo("emailVerified", true);
query.equalTo("emailSent", false);
query.each(function(user) {
user.set("emailSent", true);
user.save();
var datos = user.get("email")+"\n";
texto=texto+datos;
Parse.Cloud.run("getMaxId", {},{
success: function(results) {
console.log("Write somethingggg");
user.set("id_client", "gofoadasda");
user.save();
var datos = user.get("id_client")+"\n";
//console.log("id_client: "+datos);
response.success();
},
error: function(results, error) {
response.error(errorMessageMaker("running chained function",error));
}
}).then(function() {
// Set the job's success status
}, function(error) {
// Set the job's error status
status.error("Uh oh, something went wrong.");
});
Parse.Cloud.run("sendEmail",{
success: function(results) {
response.success(results);
},
error: function(results, error) {
response.error(errorMessageMaker("running chained function",error));
}
});
}).then(function() {
// Set the job's success status
console.log("texto: "+texto);
status.success("Migration completed successfully.");
}, function(error) {
// Set the job's error status
status.error("Uh oh, something went wrong.");
});
});
Parse.Cloud.define("sendEmail", function(request, response) {
Parse.Cloud.httpRequest({
url: 'http://www.example.com/sendemail.php',
params: {
email : 'email#email.com'
},
success: function(httpResponse) {
console.log(httpResponse.text);
},
error: function(httpResponse) {
console.error('Request failed with response code ' + httpResponse.status);
}
});
});
Parse.Cloud.define("getMaxId", function(request,response) {
var query = new Parse.Query(Parse.User);
query.descending("id_client");
query.find({
success: function(results) {
var idmax=results[0].get("id_client")
console.log("idmax: "+idmax);
response.success(idmax);
},
error: function() {
response.error(" is an error");
}
});
});
FIRST CHANGES:
After #danh help, I tried to do what I need, changing some code:
Important: id_client is a int value which it's unique for each user, it starts at 20000.
get all the users with the flag sentEmail=false.
For each of those users, getMaxId (this returns the actual max "id_client" value for all the users).
Change value of sentEmail to true, set user id_client to the actual max id.
Send email.
New code (sendEmail has no changes):
var _ = require('underscore');
// return a promise to get the max value of id_client in the user table
function getMaxId(user) {
var query = new Parse.Query(Parse.User);
//return query.count();
query.descending("id_client");
query.limit(1);
return query.find().then(function(users) {
if(users[0].get("id_client")<20000){ //No users yet.
user.set("id_client", 20000); //First id:20000
user.save();
return 20000;
}
else{ //There are users. Get the maxId and increment +1.
user.set("id_client", users[0].get("id_client")+1);
user.save();
return (users.length)? users[0].get("id_client")+1 : 0;
}
});
}
// return a promise for users with emailSent flag == false
function usersWithUnsentEmail() {
var query = new Parse.Query(Parse.User);
query.equalTo("emailSent", false);
return query.find();
}
// return a promise to send email to the given user, and to set its
// emailSent flag = true
function sendEmailToUser(user) {
return sendEmail(user.get("email")).then(function() {
user.set("emailSent", true);
return user.save();
});
}
Parse.Cloud.job("test", function(request, response) {
// Set up to modify user data
Parse.Cloud.useMasterKey();
usersWithUnsentEmail().then(function (users){
var emailPromises = _.map(users, function(user) {
//what I understand is that here, for each user, we call getMaxId, getting the actual max id_client, and then, we pass it to "sendEmailToUser".
return getMaxId(user).then(function(max){
return sendEmailToUser(user);
});
});
return Parse.Promise.when(emailPromises);//This means that we have looped all users, is it?
}).then(function(results) {
response.success(results);
}, function(error) {
response.error(error);
});
});
I've tested this with 2 users with the flag "sentEmail" = false and actual max id_client was 20001
Result:
sentEmail flags changed correctly.
2 emails sent correctly.
Error here: id_client for both users changed to 20002. It has to be 20002 and 20003.
Logs in parse:
I2015-04-22T09:44:13.433Z] v90: Ran job test with:
Input: {}
Result: undefined
E2015-04-22T09:44:29.005Z] v90: Ran job test with:
Input: {}
Failed with: Error: Job status message must be a string
at updateJobMessageAndReturn (<anonymous>:790:7)
at Object.success (<anonymous>:828:9)
at main.js:217:18
at e (Parse.js:3:8736)
at Parse.js:3:8185
at Array.forEach (native)
at Object.x.each.x.forEach [as _arrayEach] (Parse.js:1:661)
at c.extend.resolve (Parse.js:3:8136)
at Parse.js:3:8815
at e (Parse.js:3:8736)
EDITED:
We need their email and the id_client that we will assign them.
May be I haven't explained well, the email won't be sent to the user email, the email will be sent to a email that I've determined in the sendemail.php script, and it will be always the same.
I'll explain: You have a local database at home, and parse database. When this Parse.job is called, it will send an email to you (email of php) with a list of the email and the id_client of each user updated. Now you can manually update your local database with the email received info.
So, for this reason, it will be better to send only one email, at the end of all the updates. (I didn't say that because I had a lot of problems yet trying to understand how cloudCode works...)
There are a few things that need fixing in the code: (1) as a rule, use promises if you're doing more than two consecutive asynchronous things, (2) don't call Parse.Cloud.run from cloud code, it's what you call from clients who wish to invoke cloud functions, (3) style-wise, you'll go nuts trying to figure it out later on unless you break the code into small, promise-returning steps.
I've applied all three bits of advice to your code. I don't fully understand the logic as described in code and text, but hopefully I got close enough for you to make sense of it.
// using underscore js, which provides _.map below as well as loads of other useful stuff
var _ = require('underscore');
// return a promise to get the max value of id_client in the user table
function getMaxId() {
var query = new Parse.Query(Parse.User);
query.descending("id_client");
query.limit(1);
return query.find().then(function(users) {
return (users.length)? users[0].get("id_client") : 0;
});
}
// return a promise for users with emailSent flag == false
function usersWithUnsentEmail() {
var query = new Parse.Query(Parse.User);
query.equalTo("emailSent", false);
return query.find();
}
// return a promise to send email to the given user, and to set its
// emailSent flag = true, and to set its clientId to the passed value
function sendEmailToUser(user, idClient) {
return sendEmail(user.get("email")).then(function() {
user.set("emailSent", true);
user.set("id_client", idClient);
return user.save();
});
}
// return a promise to send email to the given email address via an http service
function sendEmail(email) {
var params = {url: 'http://www.example.com/sendemail.php', params: {email : email} };
return Parse.Cloud.httpRequest(params);
}
Parse.Cloud.job("test", function(request, response) {
// Set up to modify user data
Parse.Cloud.useMasterKey();
var maxIdClient;
getMaxId().then(function(result) {
maxIdClient = result;
return usersWithUnsentEmail();
}).then(function(users) {
var emailPromises = _.map(users, function(user) {
return sendEmailToUser(user, maxIdClient);
});
return Parse.Promise.when(emailPromises);
}).then(function(results) {
response.success(results);
}, function(error) {
response.error(error);
});
});
EDIT - we're kind of working on logic here particular to the app, as opposed to the concept of promises, but here goes anyway. To restate the functional requirement: We want a job to find users who have not yet been recorded in another database, represented by a flag called "emailSent". Our goal is to assign these users a unique id, and send their info (for now, we'll say email address and that id) via email to some fixed destination.
So
// getMaxId() from above is almost ready, except the minimum id_client
// value is 20000, so change the line that set this to:
return (users.length)? users[0].get("id_client") : 20000;
// usersWithUnsentEmail() from above is fine
// delete sendEmailToUser() since we're not doing that
// change sendEmail() to take an array of users to be conveyed to
// the other database. Send email about them, then change each user's
// emailSent status and save them
function sendEmail(users) {
var params = {url: 'http://www.example.com/sendemail.php', params: {users : JSON.stringify(users)} };
return Parse.Cloud.httpRequest(params).then(function() {
_.each(users, function(user) {user.set("emailSent", true);});
return Parse.Object.saveAll(users);
});
}
// add a function that takes an array of users, updates their
// id_client to be a new, unique value, and sends mail about them
// to a remote server
function synchUsers(users, idMax) {
_.each(users, function(user) {
user.set("id_client", idMax);
idMax += 1;
});
return sendEmail(users);
}
// update the job taking all this into account
Parse.Cloud.job("test", function(request, response) {
// Set up to modify user data
Parse.Cloud.useMasterKey();
var maxIdClient;
getMaxId().then(function(result) {
maxIdClient = result;
return usersWithUnsentEmail();
}).then(function(users) {
return synchUsers(users, maxIdClient+1);
}).then(function(results) {
response.success(results);
}, function(error) {
response.error(error);
});
});

Call update in Parse Cloud Code

I know there were similiar questions, but I see no solution in them.
I want to create new object if it doesn't exists in database, and update if one exists.
Here is my simple code :
Parse.Cloud.beforeSave("Tag", function(request, response) {
var query = new Parse.Query("Tag");
query.equalTo("name", request.object.get("name"));
query.first({
success: function(result) {
if (!result) {
response.success();
} else {
result.increment("popularityCount");
result.save();
}
},
error: function(error) {
alert("Error: " + error.code + " " + error.message);
}
});
});
As you see, I am calling it beforeSave. If query doesn't find anything, creates new entry. If query finds something, it should take this result, and popularityCount. But it doesn't. It works only if I call response.success() after that, but calling this function causes also in creating new entry.
It seems wrong to increment a counter on an object on every save. What if the object is modified for some other reason? If you really do want to increment a field on every save, there's no need for a query -- the object being saved is passed to the function. Moreover, a query will not work in the case where a new object is being saved.
How about instead, find or create the object as one operation, increment the counter when app logic calls for it
function findOrCreateTagNamed(name) {
var query = new Parse.Query(Tag);
query.equalTo("name", name);
return query.first().then(function(tag) {
// if not found, create one...
if (!tag) {
tag = new Tag();
tag.set("popularityCount", 0);
tag.set("name", name);
}
return (tag.isNew())? tag.save() : Parse.Promise.as(tag);
});
}
function incrementPopularityOfTagNamed(name) {
return findOrCreateTagNamed(name).then(function(tag) {
tag.increment("popularityCount");
return tag.save();
});
}
Now there's no need for beforeSave logic (which seems like the right thing to do, not a workaround).
Parse.Cloud.beforeSave("Tag", function(request, response) {
var tag = request.object;
tag.increment("popularityCount");
response.success();
});

Changing values of Parse column using Parse Code Cloud Javascript function

So its my first time writing Javascript so please bear with me. I wrote this function in order to query a class in my Parse.com application, and then after querying I want to set one of the columns (of type Boolean) to true.
I set up a test class with only 7 values in order to test.
The problem: only 3 out of 7 are being changed. Do I have to wait after each save? I know that waiting/sleeping in Javascript is "wrong" but I can't seem to find a solution.
Thanks in advance!
Additionally, when using iOS/Parse, I would like to check if the boolean value is undefined in Objective-C, I already tried to compare it to nil/NULL, an exception was thrown
Parse.Cloud.define("setYears", function(request, response) {
var object = new Parse.Query("testClass");
object.find({
success: function(results)
{
for (var i = 0; i < results.length; i++) {
results[i].set("testBool",true);// = true;
results[i].save(null,
{
success:function ()
{
response.success("Updated bool!");
},
error:function (error)
{
response.error("Failed to save bool. Error=" + error.message);
}
});
};
response.success();
}
})
});
It turned out to be not that difficult to solve as stated above. Just had to use saveAll instead of saving each object by itself. Here is the correct solution if anybody needs it:
Parse.Cloud.define("setYears", function(request, response) {
var object = new Parse.Query("testClass");
object.find({
success: function(results)
{
for (var i = 0; i < results.length; i++) {
results[i].set("testBool",true);// = true;
}
Parse.Object.saveAll(results,{
success: function(list) {
// All the objects were saved.
response.success("ok " ); //saveAll is now finished and we can properly exit with confidence :-)
},
error: function(error) {
// An error occurred while saving one of the objects.
response.error("failure on saving list ");
},
});
response.success();
}
})
});

Fetch data on different server with backbone.js

I can't see what the problem with this is.
I'm trying to fetch data on a different server, the url within the collection is correct but returns a 404 error. When trying to fetch the data the error function is triggered and no data is returned. The php script that returns the data works and gives me the output as expected. Can anyone see what's wrong with my code?
Thanks in advance :)
// function within view to fetch data
fetchData: function()
{
console.log('fetchData')
// Assign scope.
var $this = this;
// Set the colletion.
this.collection = new BookmarkCollection();
console.log(this.collection)
// Call server to get data.
this.collection.fetch(
{
cache: false,
success: function(collection, response)
{
console.log(collection)
// If there are no errors.
if (!collection.errors)
{
// Set JSON of collection to global variable.
app.userBookmarks = collection.toJSON();
// $this.loaded=true;
// Call function to render view.
$this.render();
}
// END if.
},
error: function(collection, response)
{
console.log('fetchData error')
console.log(collection)
console.log(response)
}
});
},
// end of function
Model and collection:
BookmarkModel = Backbone.Model.extend(
{
idAttribute: 'lineNavRef'
});
BookmarkCollection = Backbone.Collection.extend(
{
model: BookmarkModel,
//urlRoot: 'data/getBookmarks.php',
urlRoot: 'http://' + app.Domain + ':' + app.serverPort + '/data/getBookmarks.php?fromCrm=true',
url: function()
{
console.log(this.urlRoot)
return this.urlRoot;
},
parse: function (data, xhr)
{
console.log(data)
// Default error status.
this.errors = false;
if (data.responseCode < 1 || data.errorCode < 1)
{
this.errors = true;
}
return data;
}
});
You can make the requests using JSONP (read about here: http://en.wikipedia.org/wiki/JSONP).
To achive it using Backbone, simply do this:
var collection = new MyCollection();
collection.fetch({ dataType: 'jsonp' });
You backend must ready to do this. The server will receive a callback name generated by jQuery, passed on the query string. So the server must respond:
name_of_callback_fuction_generated({ YOUR DATA HERE });
Hope I've helped.
This is a cross domain request - no can do. Will need to use a local script and use curl to access the one on the other domain.

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