Re: [NTG-context] XML and math

10 Jan 2019


      On Fri, 11 Jan 2019, Henri Menke wrote:
...
On 11/01/19 10:26 AM, Aditya Mahajan wrote:
...
Hi,
I have an XML file (which is generated via a program that I have no
control over), which contains elements as follows:
         <p>
            <equation text="$$y_1(t) = 1, t \geq 0$$">
               <img alt="$$y_1(t) = 1, t \geq 0$$" class="equation"
height="15px" src="Lab01_eq10401623798909303081.png" width="95px"/>
            </equation>
         </p>
I want to typeset the `text` attribute of equation (and ignore the <img>
tag). So, I tried:
\startxmlsetups matlab
  % Bunch of missing definitions
  \xmlsetsetup{#1}{equation}{matlab:*}
\stopxmlsetups
\startxmlsetups matlab:equation
  \xmlatt{#1}{text}
\stopxmlsetups
This literally typesets `$$y_1(t) = 1, t \geq 0$$`. How can I flush the
attribute using ctxcatcodes? (There is \xmlflushcontent, but that is for
content and not attributes).
You could write your own attribute fetcher in Lua.  Probably there is a
more elegant method.
\startbuffer[test]
        <p>
           <equation text="$$y_1(t) = 1, t \geq 0$$">
              <img alt="$$y_1(t) = 1, t \geq 0$$" class="equation"
height="15px" src="Lab01_eq10401623798909303081.png" width="95px"/>
           </equation>
        </p>
\stopbuffer
\startxmlsetups matlab
 % Bunch of missing definitions
 \xmlsetsetup{#1}{p}{matlab:*}
 \xmlsetsetup{#1}{equation}{matlab:*}
\stopxmlsetups
\startxmlsetups matlab:p
 \xmlflush{#1}
\stopxmlsetups
\startxmlsetups matlab:equation
 \xmlfunction{#1}{equation}
\stopxmlsetups
\startluacode
local a = "text"
local ctxcatcodes = catcodes.numbers.ctxcatcodes
function xml.functions.equation(id)
   local e = lxml.getid(id)
   if e then
       local at = e.at
       if at then
           local att = at[a]
           if att ~= "" then
               context.sprint(ctxcatcodes,att)
           end
       end
   end
end
\stopluacode
\xmlregistersetup{matlab}
\starttext
\xmlprocessbuffer{test}{test}{}
\stoptext
Thanks!

Aditya