Invisible binded data

Hello everyone,

I have an issue when I bind data into an input:
When I click on a button, I want to bind data into an input.
Here is how is described my input :

<input id="location-input" type="text" placeholder="Location" ng-model="ad.location">

and here is the controller :

$ = {
    location : "my text"

What is strange is that when I click on the button, I can’t see anything in the input, but then if I give the focus to the input, the binded data appears.

Do you know why the data is invisible until I focus on the input ?

Thank you for your help

Sorry, I found the solution :