Introduction to WebUI

WebUI is a graphical user interface that is available to the connected devices. It acts as an application running on the RDK-B stack and performs the functions of a device management interface similar to TR69 & SNMP. A user can monitor and modify RDK-B feature settings/rules using WebUI. It is a client–server application, client runs in a web browser (as part of devices connected over LAN) and Lighttpd on the RDK-B stack acts as server.

The functions in WebUI are defined in C and are called from PHP using ZEND_API. PHP and the Zend Engine manage [exchange] variables internally over the D-Bus.

As part of TinyRDK initiative, WebUI is developed in Java script using duktape as JavaScript engine with a focus on portability and compact footprint. All php pages will be in Java script. User interface remains the same.

What is duktape and why it is required?

• Duktape is a lightweight javascript engine (https://duktape.org/).
• Alone it does not provide a web development engine. Therefore, a template engine(called jst) and web server api is built on top of duktape.
• Duktape provides an API to bind javascript to C functions.

Focus on migration                    

• To make migration as easy as possible the template and api signature will match php as closely as possible.  
• Many php functions and variables will be rewritten in javascript, so that changes to the exits code are minimized.
• The template engine will provide the same features as php's basic templating where php code, embedded in <?php...?> tags, can be mixed with raw html. 
• The pages are jst pages and the script tags are <?% ... %>, which is similar to other engines like EJS and JavaServer pages.

How jst changes are handled in code?

• All the pages in php are converted to jst by compiling and running the script build_php2jst.sh.
• With latest code , jst is enabled by default in CMF using DISTRO_FEATURES.

• Recipe files in source code
  meta-rdk-broadband/recipes-ccsp/ccsp/ccsp-webui-jst.bb
  meta-rdk-ext/recipes-support/duktape/duktape_2.2.0.bb
  meta-rdk-broadband/recipes-ccsp/ccsp/jst.bb
• Webui jst source code is available at rdkb/components/opensource/ccsp/webui/source/Styles/xb3/jst
• Files in GW

jst file path - /usr/www2
css, img, js, syndication partner logo - /usr/www2/cmn/
set actions are handled in /usr/www2/actionHandler
javascript implementation for php api - /usr/www2/includes/php.jst

• "/etc/webgui.sh" will modify "/etc/lighttpd.conf" on runtime and create "/tmp/lighttpd.conf"