By default, the document state is empty, but we can add custom data with the amp-state component (amp-state is included with amp-bind). For example, we could set a state property for a customer's username like this:
<amp-state id="user"> <script type="application/json"> { "username": "ruadhan" } </script></amp-state>
Note the id of the amp-state element. This would result in the following state:
{ user: { username: "ruadhan" }}
Whenever we create a state using the amp-state element, we access data within the state using the id of the element with dot or bracket syntax. So, user.username (or user[username]), in this case, would evaluate to ruadhan.
A neat thing about amp-state is that it can be fetched from ...
