Allow amp-iframe to set amp-bind state on parent #10828
Description
What's the issue?
Feature request.
Inside an amp-form I want to create a custom "coordinate input" component that lets a user pan an embedded Google Map and the current latLng is sent as a form input.
I hoped I could use amp-iframe and amp-bind and when the map moves, call something like:
postMessage({
sentinel: 'amp',
type: 'set-state',
state: {
lat: theMapLat,
lng: theMapLng,
}
}, '*' );
My form would have something like this:
<input type="hidden" name="lat" [value]="lat"/>