CODEWITHSUNDEEP
angularjsfirebase-realtime-databaseangularfire
Zaid Mirza
Zaid Mirza

Reputation: 3699

Firebase Sync handling

I have data structure like below:

-Company
       |
      -jskdhjJKHh-Yty
        -companyName:CompanyTH

-Employees
   |
  -shdjasjdshy665-333
      |
     -empName:Peter
      |
     -Company
       -jskdhjJKHh-Yty:true

Im pushing data of Employees like below in ParentController:

Step 1:

var ref=firebase.database().ref("Employees");
var newKey=ref.push({empName:"John"}).key

Setup 2:

var childCompany=ref.child(newKey+'/Company');
childCompany.set(true);

Step 3:

$scope.emplist=$firebaseArray(ref);

In HTML:

<div ng-repeat="emp in emplist" ng-Controller="ChildController">
    <p>{{emp.empName}}</p>
    <p>{{CompanyName}}</p>
</div>

In ChildController:

var companyRef=firebase.database().ref("Company/"+Object.keys($scope.emp.Company)[0]);
$scope.CompanyName=$firebaseObject(companyRef);

Problem is :

When Step 1 executed it sync data to $scope.emplist and ChildController executed for that ng-repeat instance and when code in ChildController try to execute line Object.keys($scope.emp.Company)[0] it gives error that Company is not defined. This error is beacause Step 2 is not executed and firebase sync data after Step 1.But when Step 2 is executes it updates firebase-database but ChildController does not executes on updatation of ng-repeat instance.

One Solution in my mind that somehow Can I stop Firebase to sync data until all push queries finish? or any of you guys have any other solution?

One thing to note:

Above mentions steps executes successfully when I run it 2nd time again in same session of application, it is strange that it don't run in first attempt.

Upvotes: 1

Views: 285

Answers (1)

Reaz Murshed
Reaz Murshed

Reputation: 24211

If I have understood your problem correctly, then you might have to change your push logic a bit.

Its always handy to save data in a specific node in Firebase in a single push command. As far as I can see, you're trying to push the data Employees node in two steps. Is it really necessary? You can easily push the empName and the childCompany at once using a single push.

And in your ChildController, you need to add a listener to that node from where you're trying to fetch the data using ref.on. So that you get a callback after a successful store of the data in your Firebase database. 

var companyRef=firebase.database().ref("Company/"+Object.keys($scope.emp.Company)[0]);
companyRef.on("value", function(data) {
  // This will be triggered once there's a
  // change in data in the node the reference is referring to
  doSomething();
});

Update

then how I can use set(true) within push?

Take a single object containing both empName and childCompany. Then just use push like this. 

// Get the firebase reference of your node
var ref = firebase.database().ref("Employees");

// Create an object first. 
var employee = {
  empName: "Peter",
  company: "CompanyTH"
};

// Pass the object that you've prepared earlier here. 
ref.push.set(employee);

This is just an example. You can have nested object. The idea is to passing the whole object at once and add a callback on successful save in Firebase. You might think of something like this too. 

ref.set(employee, function(error) {
  if (error) {
    doSomethingOnError();
  } else {
    doSomethingOnDataSavedSuccessfully();
  }
});

You can try building nested classes like this

var employee = {
  empName: "Peter",
  Company: {
    companyName: "Name",
    uniqueID: true
  }
};

Upvotes: 1

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