Search code examples
clojurescriptmathjaxclojurescript-javascript-interop

Using MathJax in ClojureScript

I want to use MathJax in a ClojureScript program to typeset some math in a DOM element, not the whole page (which works), just this one particular DOM element. (It's the live preview pane of a Markdown editor that also formats math in the Latex format.)

According to this documentation page on the MathJax site, you can use something like this in JavaScript.

MathJax.Hub.Queue(["Typeset", MathJax.Hub, latex-node]);

I've been using trial and error and have not gotten it right. Something like this:

(defn typeset-latex
  [latex-node]
  (.Queue js/MathJax.Hub ["TypeSet" (.-Hub js/MathJax) latex-node]))

compiles and does not produce any errors when run, but does not yield any output either.

Using the js* macro to try to reproduce the method on the documentation page:

(js* "MathJax.Hub.Queue([\"TypeSet\", MathJax.Hub, \"mde-preview-id\"]);")

produces an error message in the browser stating that "Error: Can't make callback from given data".

ALSO: Assuming I can get the syntax right to get typesetting working in figwheel, any guidance on how to setup the externs file for use with an optimized build would be appreciated.

Solution

  • You're close. I think you just need to make the Clojure vector into a JavaScript list. You can use the #js reader macro:

    (defn typeset-latex
  [latex-node]
  (.Queue js/MathJax.Hub #js ["Typeset" (.-Hub js/MathJax) latex-node]))

    Here is a line of code in one of my own projects that's equivalent, though it uses slightly different syntax.

    Update: change TypeSet to Typeset.