July 22, 2015 —

FirebaseSharp 2.0 – Setting Priority

Since we can order by priority, it sure would be nice to be able to set priorities with FirebaseSharp.

And now we can!

 var root = app.Child("/");
 
// now update the priorites
root.Child("aaa").SetWithPriority("{}", 3);
root.Child("bbb").SetWithPriority("{}", 2);
root.Child("ccc").SetWithPriority("{}", 1)

In this example we end up with a tree that looks like this:

{
  'aaa': {
    '.priority': 3
  },
  'bbb': {
    '.priority': 2
  },
  'ccc': {
    '.priority': 1
  },
}

Now we can order the values by priority and see that they are returned in priority, not key lexical, order.

root.OrderByPriority().Once("value", (snap, child, context) => {
  var children = snap.Children.ToArray();
  Assert.AreEqual("ccc", children[0].Key);
  Assert.AreEqual(1, float.Parse(children[0].GetPriority().Value));
  Assert.AreEqual("bbb", children[1].Key);
  Assert.AreEqual(2, float.Parse(children[1].GetPriority().Value));
  Assert.AreEqual("aaa", children[2].Key);
  Assert.AreEqual(3, float.Parse(children[2].GetPriority().Value));
});

Also notice that you can now use the IDataSnapshot::GetPriority method to get the priority information from the snapshot (and it’s children).

In this example I used SetWithPriority – but you can also use SetPriority to add a priority to an existing query location. For example:

root.Child("aaa").SetPriority(3);
root.Child("bbb").SetPriority(2);
root.Child("ccc").SetPriority(1);

In this example we are setting the priority, over-writing any existing priority, at the query location.

See Also:

getPriority

setWithPriority

setPriority