Using the Behaviors property you can add behaviors that attached to the Control and can execute code when events of that control are raised.
Documentation: Introduction to Behaviors Example Use Case: Apply validation rules to an Entry control. We can use the Is Valid property to bind to something just as a Button Is Enabled Property or similar to stop users from progressing forward without meeting the forms requirements.
The redirect URL must be absolute HTTPS URL otherwise AMP will throw an error and redirection won't happen.
Known Issue: Due to an issue in Safari i OS redirecting to deep linked URLs (URLs that would actually end up opening a native app) might fail when the AMP document is embedded. provide polyfills for behaviors and functionality missing from some browsers or being implemented in the next version of CSS.
This behavior is consistent across all browsers and is known as implicit submission. Implicit submission is vital to assistive technologies and impaired users that cannot use a mouse at all.
From the HTML5 specification: The spec strongly encourages browsers to allow implicit submission; they all do.
Documentation: Introduction to Effects Example Use Case: Changing the color of the placeholder text in an Entry control.
First on the native platform, in this example i OS, we create a Platform Effect.
You can read more about Actions and Events in AMP in the spec.
Before I tell you why you care, let’s look at how this should work.
Take the following basic form: If you have focus in the textbox and hit enter, the form will be submitted automatically.
“If the user agent supports letting the user submit a form implicitly (for example, on some platforms hitting the “enter” key while a text field is focused implicitly submits the form), then doing so for a form whose default button has a defined activation behavior must cause the user agent to run synthetic click activation steps on that default button.” “If the form has no submit button, then the implicit submission mechanism must do nothing if the form has more than one field that blocks implicit submission, and must submit the form element from the form element itself otherwise.
For the purpose of the previous paragraph, an element is a field that blocks implicit submission of a form element if it is an input element whose form owner is that form element and whose type attribute is in one of the following states: Text, Search, URL, Telephone, E-mail, Password, Date and Time, Date, Month, Week, Time, Local Date and Time, Number” handler on a button.
attribute to execute an action on any element when an input value changes.