Having issues reading from the database

[jalasem]

I am building a blog powered by firebase just to try it out on my own. But issues looping through my posts. this code :

firebase.database().ref('blog/').child('posts/')on('value', function(snap){
      console.log(snap.val());
});

and 

firebase.database().ref('blog/').child('posts/').on("value", snap => {
      for (let post in snap.val()) {
          console.log(post)
      }
});

returns objects with probably the post ids of those objects which I dont know how to determine that.
My question is Do I have to work with postId?
If yes, how? and if no, How?

[nicolasgarnier]

Hey @jalasem

This will trigger once per post, and then keep listening for new incoming posts (see the child_changed instead of value):

firebase.database().ref('blog/').child('posts/')on('child_changed', function(snap){
      console.log(snap.val()); // value of the post
      console.log(snap.key); // ID of the post
});

Alternatively you can use once which will trigger just once and in this csae return all blog posts. but you won't be notified of new posts:

firebase.database().ref('blog/').child('posts/').once('value').then(function(snap){
  snap.foreach(function(posts){
      console.log(posts.val()); // value of the post
      console.log(posts.key); // ID of the post
  });
});

[jalasem]

Thanks a lot! You are awesome. Where can I find this in the documentation, because the documentation the way I see it is more or less of a tutorial on how to build a chat app.
I suggest firebase web documentation should be more explanatory

[nicolasgarnier]

Here is the relevant doc: https://firebase.google.com/docs/database/web/retrieve-data
Especially see the Listen for events section which described every type of event you can listen to and the Read data once section which explains how to use the .once.

We're indeed using a chat app as a way to illustrate the docs by showing an example you can follow. If you have different ideas, feedback or see any error in the docs we'd love to hear about it. You can use the "Send Feedback" button in the docs and this will go directly to out tech writer team:

Cheers!