Execute Callback

Using this action, you can trigger actions defined on a page (i.e., outside of a component) from inside a widget of a component.
Normally, when you add a component to your page, you can add actions on a tap of the entire component, but you can't trigger those actions from a widget inside of a component (e.g., a button in a card component). This action allows you to do just that. Basically, you define actions on a page, pass them to a component (as a parameter) and then trigger them from any widget of a component.
This action is very helpful when you need lots of conditional actions based on a page elements value (i.e., widget state) and you want to use the action output variable in page widgets. Without this action, it would be very difficult, as you can't access the page widgets' state/properties from within a component.
Without Execute Callback action
With Execute Callback action

Adding Execute Callback action

Let's build an example that uploads the image when a button widget (inside the component) is tapped. Because we have to display the uploaded image on a page widget, we won't add an upload action directly on a button. Instead, we'll pass the upload action from a page and use the Execute Callback action to trigger the upload action. Finally, we'll use the Uploaded File URL to display the image on a page.
Here's how it looks when completed:
Uploading image using Execute Callback action
Here are step-by-step instructions:

1. Define a parameter on a component

To trigger actions outside of the component, you must create/define a parameter on a component that will receive the actions from outside. While doing so, ensure you set the Type to Action for this example to work.
Currently, you can add only one parameter of this type (Action).
Define a parameter on a component

2. Pass action from page to component

See how to pass data from a page to a component. Note: To pass action, Open the Action flow Editor in a new popup window, and here you can add the Upload Action.
Pass action from page to component
You can also try adding some conditional actions that are based on a page widget's state, such as allowing uploading if certain conditions are met.
Passing conditional actions

3. Trigger Execute Callback action

Finally, to trigger the actions received from outside of a component, you can use the execute callback action. Here's how you do it:
  1. 1.
    Select the widget inside the component.
  2. 2.
    Select Actions from the properties panel (the right menu), and click + Add Action button.
  3. 3.
    Search and select the Execute Callback (under Utilities) action.
  4. 4.
    Set the Callback to the parameter name (of type Action) that receives the actions from outside.
Trigger Execute Callback action