quil js parchment error

Question

I get a an error when trying to use a formula module in quill.

The error is:

"[Parchment] Unable to create formula blot"

Following the error message in chrome web development tools leads to the following line in registry.ts (webpack:///./~/parchment/src/registry.ts)

function create(input, value) {
    var match = query(input);
    if (match == null) {
        throw new ParchmentError("Unable to create " + input + " blot");
    }
    var BlotClass = match;
    var node = input instanceof Node ? input : BlotClass.create(value);
    return new BlotClass(node, value);
}

It happens when I try to insert a formula.

This happens when I am using the quill-rails5 but also without using the gem. I removed the gem to simplify the problem. Here is my code:

 var quill = new Quill('#editor', {
      modules: {
 formula: true,   
        toolbar: [
          [{ header: [1, 2, false] }],
          ['bold', 'italic', 'underline'],
          ['image', 'code-block'],
          ['formula'],
        ]
      },
      placeholder: 'Compose a solution...',
      theme: 'snow'  // or 'bubble'
    });

my editor container

  <div id="editor">
      <%= raw sanitize @post.description, tags: %w(strong em div a p br ul ol li), attributes: %w(href) %>
  </div>

Answer 1

Did you include katex.js and katex.css as explained in the docs?

A working example:

<!-- Include KaTeX stylesheet -->
<link href="katex.css" rel="stylesheet">

<!-- Include KaTeX library -->
<script href="katex.js" type="text/javascript"></script>

<script type="text/javascript">
var quill = new Quill('#editor', {
  modules: {
    formula: true,          // Include formula module
    toolbar: [['formula']]  // Include button in toolbar
  },
  theme: 'snow'
});
</script>