Hi! 6 years ago HLS wrote an article on Dzone https://dzone.com/articles/tapestry-54-focus-javascript which contained among other things following very promising paragraph. See below.
Is this kind of functionality still on the agenda? What can we expect by Tapestry 5.5? Best Regards Reinhold *************************************************************************************************************************************** Embrace client-side controller logic The changes discussed so far only smooth out a few rough edges; they still position Tapestry code, running on the server, as driving the entire show. As alluded to earlier; for any sophisticated user interface, the challenge is to coordinate the client-side user interface (in terms of form fields, DOM elements, and query parameters) with the server-side components; this is encoded into the hidden t:formdata field. However, it is my opinion that for any dynamic form, Tapestry is or near the end of the road for this approach. Instead, it's time to embrace client-logic, written in JavaScript, in the browser. Specifically, break away from HTML forms, and embrace a more dynamic structure, one where "submitting" a form always works through an Ajax update ... and what is sent is not a simple set of query parameters and values, but a JSON representation of what was updated, changed, or created. My specific vision is to integrate Backbone.js (or something quite similar), to move this logic solidly to the client side. This is a fundamental change: one where the client-side is free to change and reconfigure the UI in any way it likes, and is ultimately responsible for packaging up the completed data and sending it to the server. When you are used to the BeanEditForm component, this might feel like a step backwards, as you end up responsible for writing a bit more code (in JavaScript) to implement the user interface, input validations, and relationships between fields. However, as fun as BeanEditForm is, the declarative approach to validation on the client and the server has proven to be limited and limiting, especially in the face of cross-field relationships. We could attempt to extend the declarative nature, introducing rules or even scripting languages to establish the relationships ... or we could move in a situation that puts the developer back in the driver's seat. Further, there are some that will be concerned that this is a violation of the DRY pricipal; however I subscribe to different philosophy that client-side and server-side validation are fundamentally different in any case; this is discussed in an excellent blog post by Ian Bickling. Certainly there will be components and services to assist with this process, in term of extracting data into JSON format, and converting JSON data into a set of updates to the server-side objects. There's also a number of security concerns that necessitate careful validation of what comes up from the client in the Ajax request. Further, there will be new bundled libraries to make it easier to build these dynamic user interfaces. *************************************************************************************************************************************** --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tapestry.apache.org For additional commands, e-mail: users-h...@tapestry.apache.org
