Develop Reference

Azure CosmosDb Stored Procedure IfMatch Predicate

In a DocDb stored procedure, as the first step in a process retrieving data that I'm mutating, I read and then use the data iff it matches the etag like so:
collection.readDocument(reqSelf, function(err, doc) {
if (doc._etag == requestEtag) {
// Success - want to update
} else {
// CURRENTLY: Discard the read result I just paid lots of RUs to read
// IDEALLY: check whether response `options` or similar indicates retrieval
was skipped due to doc not being present with that etag anymore
...
// ... Continue with an alternate strategy
}
});
Is there a way to pass an options to the readDocument call such that the callback will be informed "It's changed so we didn't get it, as you requested" ?
(My real problem here is that I can't find any documentation other than the readDocument undocumentation in the js-server docs)

Technically you can do that by creating a responseOptions object and passing it to the call.
function sample(selfLink, requestEtag) {
var collection = getContext().getCollection();
var responseOptions = { accessCondition: { type: "IfMatch", condition: requestEtag } };
var isAccepted = collection.readDocument(selfLink, responseOptions, function(err, doc, options) {
if(err){
throw new Error('Error thrown. Check the status code for PreconditionFailed errors');
}
var response = getContext().getResponse();
response.setBody(doc);
});
if (!isAccepted) throw new Error('The query was not accepted by the server.');
}
However, even if the etag you provide is not the one that the document has, you won't get an error and you will properly get the document itself back. It's just not supposed to work with that using the readDocument function in a stored procedure.

Thanks to some pushing from #Nick Chapsas, and this self-answer from #Redman I worked out that in my case I can achieve my goal (either read the current document via the self-link, or the newer one that has replaced it bearing the same id) by instead generating an Alt link within the stored procedure like so:
var docId = collection.getAltLink() + "/docs/"+req.id;
var isAccepted = collection.readDocument(docId, {}, function (err, doc, options) {
if (err) throw err;
// Will be null or not depending on whether it exists
executeUpsert(doc);
});
if (!isAccepted) throw new Error("readDocument not Accepted");

Model return values from another file not working with Sequelize.js

I have the following code that does not work currently.
var config = require('./libs/sequelize-lib.js');
var connection = config.getSequelizeConnection();//Choosing to not pass in variable this time since this should only run via script.
var models = config.setModels(connection);//Creates live references to the models.
//Alter table as needed but do NOT force the change. If an error occurs we will fix manually.
connection.sync({ alter: true, force: false }).then(function() {
models.users.create({
name: 'joe',
loggedIn: true
}).then( task => {
console.log("saved user!!!!!");
});
process.exit();//close the nodeJS Script
}).catch(function(error) {
console.log(error);
});
sequelize-lib.js
var Sequelize = require('sequelize');
exports.getSequelizeConnection = function(stage){
var argv = require('minimist')(process.argv.slice(2)); //If this file is being used in a script, this will attempt to get information from the argument stage passed if it exists
//Change connection settings based on stage variable. Assume localhost by default.
var dbname = argv['stage'] ? argv['stage']+"_db" : 'localdb';
var dbuser = argv['stage'] ? process.env.RDS_USERNAME : 'admin';
var dbpass = argv['stage'] ? process.env.RDS_PASSWORD : 'local123';
var dbhost = argv['stage'] ? "database-"+argv['stage']+".whatever.com" : 'localhost';
//If state variable used during require overide any arguments passed.
if(stage){
dbname = stage+"_db";
dbuser = process.env.RDS_USERNAME
dbpass = process.env.RDS_PASSWORD
dbhost = "database-"+stage+".whatever.com"
}
var connection = new Sequelize(dbname,dbuser,dbpass, {
dialect: 'mysql',
operatorsAliases: false, //This gets rid of a sequelize deprecated warning , refer https://github.com/sequelize/sequelize/issues/8417
host: dbhost
});
return connection;
}
exports.setModels = function(connection){
//Import all the known models for the project.
const fs = require('fs');
const dir = __dirname+'/../models';
var models = {}; //empty model object for adding model instances in file loop below.
//#JA - Wait until this function finishes ~ hence readdirSync vs regular readdir which is async
fs.readdirSync(dir).forEach(file => {
console.log(file);
//Split the .js part of the filename
var arr = file.split(".");
var name = arr[0].toLowerCase();
//Create a modle object using the filename as the reference without the .js pointing to a created sequelize instance of the file.
models[name] = connection.import(__dirname + "/../models/"+file);
})
//Showcase the final model.
console.log(models);
return models; //This returns a model with reference to the sequelize models
}
I can't get the create command to work however with this setup. My guess is the variables must not be passing through correctly somehow. I'm not sure what I'm doing wrong?
The create command definitely works because if in the sequelize-lib.js I modify the setModels function to this...
exports.setModels = function(connection){
//Import all the known models for the project.
const fs = require('fs');
const dir = __dirname+'/../models';
var models = {}; //empty model object for adding model instances in file loop below.
//#JA - Wait until this function finishes ~ hence readdirSync vs regular readdir which is async
fs.readdirSync(dir).forEach(file => {
console.log(file);
//Split the .js part of the filename
var arr = file.split(".");
var name = arr[0].toLowerCase();
//Create a modle object using the filename as the reference without the .js pointing to a created sequelize instance of the file.
models[name] = connection.import(__dirname + "/../models/"+file);
models[name].create({
"name":"joe",
"loggedIn":true
});
})
//Showcase the final model.
console.log(models);
return models; //This returns a model with reference to the sequelize models
}
Then it works and I see the item added to the database! (refer to proof image below)
Take note, I am simply running create on the variable at this point. What am I doing wrong where the model object is not passing between files correctly? Weird part is I don't get any errors thrown in the main file?? It's as if everything is defined but empty or something and the command is never run and nothing added to the database.
I tried this in the main file also and no luck.
models["users"].create({
name: 'joe',
loggedIn: true
}).then( task => {
console.log("saved user!!!!!");
});
The purpose of this all is to read models automatically from the model directory and create instances that are ready to go for every model, even if new one's are added in the future.
UPDATE::
So I did another test that was interesting, it seems that the create function won't work in the .then() function of the sync command. It looks like it was passing it correctly though. After changing the front page to this...
var config = require('./libs/sequelize-lib.js');
var connection = config.getSequelizeConnection();//Choosing to not pass in variable this time since this should only run via script.
var models = config.setModels(connection);//Creates live references to the models using connection previosly created.
models["users"].create({
"name":"joe",
"loggedIn":true
});
//Alter table as needed but do NOT force the change. If an error occurs we will fix manually.
connection.sync({ alter: true, force: false }).then(function() {
process.exit();//close the nodeJS Script
}).catch(function(error) {
console.log(error);
});
Doing this seems to get create to work. I'm not sure if this is good form or not though since the database might not be created at this point? I need a way to get it to work in the sync function.

Well I answered my question finally, but I'm not sure I like the answer.
var config = require('./libs/sequelize-lib.js');
var connection = config.getSequelizeConnection();//Choosing to not pass in variable this time since this should only run via script.
var models = config.setModels(connection);//Creates live references to the models using connection previosly created.
//Alter table as needed but do NOT force the change. If an error occurs we will fix manually.
connection.sync({ alter: false, force: false }).then( () => {
models["users"].create({
"name":"joe",
"loggedIn":true
}).then( user => {
console.log("finished, with user.name="+user.name);
process.exit();
}).catch( error => {
console.log("Error Occured");
console.log(error);
});
}).catch(function(error) {
console.log(error);
});
turns out that process.exit was triggering before create would occur because create happens async. This means that all my code will have to constantly be running through callbacks...which seems like a nightmare a bit. I wonder if there is a better way?

Parse.com master key doesn't let to write PFUser currentUser

UPDATE: In a nutshell, I would like to use the Master key, because I need to write an other user object with my current user, but I don't want to override all security, I just wanna use it in one function. The accepted answer in this question gave a very nice starting point, however I couldn't make it to work. It's the last code block in this question.
I have two separated functions. The first is pure objective-c, it deletes users from the currentUser's firstRelation. It worked well without any problems until i added a different CloudCode function into a different view controller. The CloudCode function uses the master key and adds currentUser to otherUser's sampleRelation & adds otherUser to currentUser's sampleRelation (firstRelation and sampleRelation is two different column inside the User class).
So the problem is when I delete a user from currentUser's firstRelation (with current user) my app crashes, because the user must be authenticated via logIn or signUp. Actually i don't understand this, because in this case I'm writing the currentUser with the currentUser instead of another user, so it must work without any problems (and worked before the CloudCode).
I'm almost sure that it's because I'm using the master key with the CloudCode, but have no idea how can I avoid it. Everything else is still working, for example I can upload images with currentUser.
Here is the code that I'm using for the CloudCode, JavaScript is totally unknown for me, maybe somebody will see what causes the problem.
Parse.Cloud.define('editUser', function(request, response) {
Parse.Cloud.useMasterKey();
var userQuery = new Parse.Query(Parse.User);
userQuery.get(request.params.userId)
.then(function (user) {
var relation = user.relation("sampleRelation");
relation.add(request.user);
// chain the promise
return user.save();
}).then(function (user) {
var currentUser = request.user;
var relation = currentUser.relation("sampleRelation");
relation.add(user);
// chain the new promise
return currentUser.save();
}).then(function () {
response.success();
}, function (error) {
response.error(error);
});
});
It crashes when i try to remove the object:
PFUser *user = [self.friends objectAtIndex:indexPath.row];
PFRelation *myFriendsRel = [self.currentUser relationForKey:#"simpleRelation"];
if ([self isFriend:user]) {
for (PFUser *friendName in self.friends) {
if ([friendName.objectId isEqualToString:user.objectId]){
[self.friends removeObject:friendName];
break; // to exit a loop
}
}
// remove from parse
[myFriendsRel removeObject:user];
NSLog(#"deleted: %#", user.username);
}
[self.currentUser saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
if (error){
NSLog(#"Error %# %#", error, [error userInfo]);
}
}];
This is the newest attempt, that based Fosco's answer from the other question. It works, but the same way as the earlier versions.
Parse.Cloud.define('editUser', function(request, response) {
var userId = request.params.userId;
var User = Parse.Object.extend('_User'),
user = new User({ objectId: userId });
var currentUser = request.user;
var relation = user.relation("friendsRelation");
relation.add(currentUser);
user.save(null, { useMasterKey:true}).then(function(user) {
response.success(user);
}, function(error) {
response.error(error)
});
});

At a quick glance it looks like its failing because you're trying to remove an object from an array whilst it is being iterated. I know this causes a crash in Objective C regardless of whether you're using Parse objects or not.
Try re-writing this segment:
for (PFUser *friendName in self.friends) {
if ([friendName.objectId isEqualToString:user.objectId]){
[self.friends removeObject:friendName];
break; // to exit a loop
}
}
To something like this:
NSMutableArray *tempArray = [[NSMutableArray alloc]init];
for (PFUser *friendName in self.friends) {
if (![friendName.objectId isEqualToString:user.objectId]) {
[tempArray addObject:friendName];
}
self.friends = [NSArray arrayWithArray:tempArray];
Again, only had a quick glance so not 100% if that is your problem but it looks like it, let me know if it helps

AngularJS and Restangular, trying to convert update method to API

I'm trying to convert my basic crud operations into an API that multiple components of my application can use.
I have successfully converted all methods, except the update one because it calls for each property on the object to be declared before the put request can be executed.
controller
$scope.update = function(testimonial, id) {
var data = {
name: testimonial.name,
message: testimonial.message
};
dataService.update(uri, data, $scope.id).then(function(response) {
console.log('Successfully updated!');
},
function(error) {
console.log('Error updating.');
});
}
dataService
dataService.update = function(uri, data, id) {
var rest = Restangular.one(uri, id);
angular.forEach(data, function(value, key) {
// needs to be in the format below
// rest.key = data.key
});
// needs to output something like this, depending on what the data is passed
// rest.name = data.name;
// rest.message = data.message;
return rest.put();
}
I tried to describe the problem in the codes comments, but to reiterate I cannot figure out how to generate something like rest.name = data.name; without specifying the name property because the update function shouldn't need to know the object properties.
Here is what the update method looked like before I started trying to make it usable by any of my components (this works)
Testimonial.update = function(testimonial, id) {
var rest = Restangular.one('testimonials', id);
rest.name = testimonial.name;
rest.message = testimonial.message;
return rest.put();
}
How can I recreate this without any specific properties parameters hard-coded in?
Also, my project has included lo-dash, if that helps, I don't know where to start with this problem. Thanks a ton for any advice!

Try like
angular.extend(rest,testimonial)
https://docs.angularjs.org/api/ng/function/angular.extend

I'm having a lot of trouble trying to modify a "this" object from within a pseudo javascript class when it's already been initialized

Scroll down to the bottom of this post to see a work around / possible solution.
This is probably easier just to explain in the source code with comments. The issue at hand is I cannot figure out how pseudo classes work together to perform the task I'm trying to do (explained in the code below).
The code is broken down into 3 files: lead.js, router.js, and db.js.
There are a decent amount of lines of code but most of it is comments.
[lead.js]
var bcrypt = require('bcrypt'),
validators = require('../lib/validators'),
utility = require('../lib/utility'),
document = {};
var Lead = module.exports = function (db) {
// Save a reference to the database.
this.db = db;
// Reference initial document.
// This is totally wrong, not sure how to 'send' a variable to the constructor of a class
// when I cannot add another param. Due to how I'm importing the db model, I won't know what
// the document is until I fill out the form. I've also tried 'document' instead of 'Lead.document'.
this.document = Lead.document;
// Setup the document if it exists.
// This also doesn't work.
// Basically I want to be able to set up a document variable outside of this module (line #100),
// Then pass it to this module after filling it up with values from a form.
// Then based on what's been filled in, it would fix up (trim, convert to lower case)
// some of the values automatically and default a few values that I'm not always going to pass.
if (!document) {
var salt = bcrypt.genSaltSync(10),
hash = bcrypt.hashSync(utility.generatePassword(), salt);
// Default values.
if (!document.meta.createdAt) { this.document.meta.createdAt = Date.now(); }
if (!document.login.password) { this.document.login.password = hash; }
if (!document.login.role) { this.document.login.role = 'User'; }
// Normalize a few values.
this.document.login.email = document.login.email.toLowerCase().trim();
this.document.contact.name.first = document.contact.name.first.trim();
this.document.contact.name.last = document.contact.name.last.trim();
this.document.contact.address.street = document.contact.address.street.trim();
this.document.contact.address.city = document.contact.address.city.trim();
this.document.contact.address.state = document.contact.address.state.trim();
this.document.contact.address.zip = document.contact.address.zip.trim();
this.document.contact.phone.home = document.contact.phone.home.trim();
}
// So in regards to the above code, the end result I'm looking for is...
// I want to append some properties to the this.document reference when the document is empty (when I'm updating it, I won't set the document),
// and on new documents it will append a few default values/normalize all the fields.
};
Lead.prototype.validate = function(fn) {
var errors = [];
// Some validation rules I cut out to make this shorter.
if (errors.length) return fn(errors);
fn();
};
Lead.prototype.save = function(fn) {
this.db.collection('leads', function(err, collection) {
if (err) { fn(new Error({message: err})); }
collection.insert(this.document, function(err, result) {
return fn(err, result);
});
});
};
---
[route.js file]
var db = require('../models/db');
app.post('/register', function(req, res) {
var data = req.body.lead || {};
// Fill the document.
var document = {
meta: {
host: req.headers.host,
referer: req.headers.referer,
createdIPAddress: req.connection.remoteAddress
},
login: {
email: data.email
},
contact: {
name: {
first: data.first,
last: data.last
},
address: {
street: data.street,
city: data.city,
state: data.state,
zip: data.zip
},
phone: {
home: data.phone
}
}
};
// Write the document.
db.lead.document = document;
db.lead.validate(function(err) {
if (err) {
req.session.error = err;
return res.redirect('back');
}
db.lead.save(function(err) {
res.redirect('/register/success');
});
});
});
---
[db.js]
var mongodb = require('mongodb'),
server = new mongodb.Server('localhost', 27017),
connection = new mongodb.Db('test', server);
connection.open(function(err, db) {});
module.exports = {
lead: new (require('./lead'))(connection)
};
When I run this, my validator always reports that the password is empty which makes sense. I'm sending the document initially to the class with an empty password (the password is randomly generated, not a form field) -- the problem is I have no idea what to do with the if (!document) ... code block to actually set the this.document properly.
I hope between the comments and code you can get an idea of what I'm trying to do. I've been stuck on this for a while.
EDIT
I changed the flow of it a bit to get a solution.
In the db.js, I exported the connection rather than instantiating the lead (and future models) directly.
In the router.js file, I require the db and lead file, then pass both the db connection and the document in the constructor of the Lead. Ex.
var lead = new Lead(db, document);
In the lead.js file, it becomes as simple as doing this.document = document (same as the db). When I submit a new lead, the values I don't send over from router.js get appended to the document (the created date, a random password, etc.) and everything is good.
Is this a decent way of handling this, or is there a better way to refactor this?

This is completely wrong way even if make this code work as you want. In this example you have singleton lead. By requesting /register url you want to set 'document' field to this singleton . (IMPORTANT) But requests work asynchronously. Absolutely no guarantee that you save the document, which has just validate. Because new request may overwrite it in lead object. You need to do this logic in request scope. One scope for one request. Not one for all.

You need to read up on object-oriented programming in Javascript.
The anonymous function you're defining near the top of your code is the constructor function, so with respect to the document property you want that is currently uninitialized, just type something like:
this.document = null;
Then some time later when you create a new object using this constructor, like so:
var myLead = new Lead(dbConnection);
You'll have the myLead.document property.
There are many other things wrong with your code, though. Why are you assuming that there is a global document variable with relevant data visible in your library when it's defined as {}? The code in that if statement at the end of your constructor should be run when the document property is set in your other file below, and should only expect this.document to exist.

You set var document = {} initially, and {} is not falsy. Better would be to set as a starting value document = null and then after checking for !document set document = {} before assigning whatever properties you need.