Re: [NTG-context] XML expression to read HTML classes

27 Aug 2015


      On 8/25/2015 5:05 PM, massifr@fastwebnet.it wrote:
...
Hello list,
I'm working on HTML typesetting with ConTeXt.
I wrote a custom expression to test whether an element has a class:
function xml.functions.classes(classAttr)
   local classes = {}
   if classAttr then
     for c in string.gmatch(classAttr, "%S+") do
       if (string.len(c) > 0) then classes[c] = true end
     end
   end
   return classes
end
function xml.expressions.hasClass(classAttr, className)
   if classAttr and className then
     return xml.functions.classes(classAttr)[className] ~= nil
   end
   return false
end
This way I can write this in my xmlsetup:
\xmlsetsetup{#1}{p[hasClass(@class,'myclass1')]}{html:p:myclass1}
That is better than
- p[@class='myclass1']   (it fails when you have more classes)
- p[contains(@class, 'myclass1')]    (it gives you false positives when you have class="myclass12")
That works, but I would like to write:
\xmlsetsetup{#1}{p[hasClass('myclass1')]}{html:p:myclass1}
omitting the @class argument, because it's obvious.
To omit it I need to access the current collected element.
At page 25 of "Dealing with XML in ConTeXt MkIV" it is said
that the predefined variables "list","l","ll" (I think I need that one)
and "order" are available, but I did not manage to access them.
How can I get the current element in Lua to write
local classAttr = xml.attribute(currentElement, "", "class")   ?
function xml.functions.classes(e)
     local class = e.at.class
     if class then
         local classes = { }
         for c in string.gmatch(class,"%S+") do
             classes[c] = true
         end
         return classes
     else
         return { }
     end
end


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