Can I generate a Json file through my localhost with url: 'http://localhost:8080/ext-4.0.2a/examples/grid/my_users.php' setting in my Ajax Proxy with Json Reader?

Here is my Store object:

var userStore = Ext.create('Ext.data.Store', {
model: 'User',
proxy: {
type: 'ajax',
url: 'http://localhost:8080/ext-4.0.2a/examples/grid/my_users.php',
reader: {
type: 'json',
root: 'users',
idProperty: 'id'
}
}
});

Is this the right/OK way of doing? or do you have better suggestions?
Thanks,

-nuskin