Facebook Webview

Context: For one of our clients, we are developing a chat interface to their flight information system. In addition to standard text messages and simple templates such as buttons, we need to display more complicated interaction means to get things like dates and airports. Requirements: We need to use more complicated means such as webview to do the following: 1 - Get dates for searching for flights 2 - Display customized content for itinerary and boarding pass The first step has the following requirements: - Find out what kind of payload has to be sent to the messenger API to display an interactive date picker. A sample JSON would be enough. - Find out where the data for the picker is received from. The picker is dynamic, so the javascript and the content has to be loaded from somewhere. We need to know things like how to specify where these are loaded from, the format for HTML content, what is allowed in terms of JS and HTML etc. Also, we would like to know what kind of styling can be applied to such a picker, and how this can be specified (in the initial payload? from the application that provides the data?). - Develop a simple application that delivers the data needed for a date picker to Facebook. Ideally, this would be a Python application, but PHP would also be OK as long as it is clear what kind of data it is returning for the date picker. - Find out how to pass on the data that the user has picked to the chatbot. How is the data selected by the user passed on to the chatbot? Is it inserted into the chat stream in Messenger, or is there a postback to the app that provides the data? - For the flight search, we also need a method to search for airports. A search field with completion support would be nice. We would like to know whether this is possible, and what the requirements are. If this is doable relatively easily, sample JSON payload and application data would be required. I can give you the requirements for the second stage once the first one is completed, and we have better information on webview.