Using Firebase-util to resolve one to many relationship

Question

I\'ve been looking at the firebase util project at https://firebase.github.io/firebase-util/. I can\'t figure out if this is possible.

Say I have a data set like th

Answer 1

You cannot use a nested list of groups as the keymap for clients/$client/groups. It must be a string pointing to exactly one reference.

The solution would be to retrieve the list separately from the meta data for the user:

var fb = new Firebase(URL);

getClients(fb.child('clients'), function(userId, data) {
   console.log(userId, data);
});

function getGroupsForClient(clientId, callback) {
   var indexRef = fb.child('clients/'+clientId+'/groups');
   var groupsRef = fb.child('groups');
   var intersectionRef = new Firebase.util.intersection(indexRef, groupsRef);
   intersectionRef.once('value', callback);
}

function getClients(callback) {
   fb.child('clients').on('child_added', function(snap) {
      var userId = snap.name();
      var userData = snap.val();
      getGroupsForClient(userId, function(snap) {
         userData.groups = snap.val();
         callback(userId, userData);
      });
   });
}