Custom parameters

To make a self-written LuaFilter look more like a regular filter, you should

• write your script in a separate lua file instead of doing it directly in the web.xml
• Define a prefix with the "NameSpace" directive in the LuaFilter

Example

filter>
            <filter-name>LuaFilter</filter-name>
            <filter-class>ch::nevis::isiweb4::filter::lua::LuaFilter</filter-class>
            <!-- Declare Naspace for Variables that will be available in the external
Script -->
            <init-param>
                <param-name>Script.Namespace</param-name>
                <param-value>My</param-value>
            </init-param>
 
            <init-param>
                    <param-name>MyFancyParameter</param-name>
                    <param-value>Something</param-value>
            </init-param>
            <init-param>
                <param-name>Script.OutputFunctionName</param-name>
                <param-value>outputStream</param-value>
            </init-param>
            <init-param>
                <param-name>Script.Path</param-name>
                <param-value>/path/to/my/script.lua</param-value>
            </init-param>
</filter>

The MyFancyParameter is now visible in the /path/to/my/script.lua

function outputStream(req, res, chunk)
   if MyFancyParameter ~= nil then
       res:setHeader("TestVariable", MyFancyParameter)
   end
   return chunk
end