Support Mermaid's callback configuration

Mermaid has the ability (see src/mermaid.js) to invoke a user-configured callback function as it renders each diagram:

mermaid.initialize({
  startOnLoad: true,
  mermaid: {
    callback: function(id) {
      // ...
    },
  },
});

This is invaluable for doing any number of things on Mermaid diagrams that simply cannot be done with CSS.

Right now, I don’t see any way to configure a Mermaid callback function in this plugin. Could that be supported in the plugin configuration? The obvious way would seem to be as follows:

plugins:
  - mermaid2:
      arguments:
        theme: neutral
      callback: myMermaidCallbackFunction

[fralau]

It’s now published on pypi under 0.3.1.

[artob]

Could you let me know if it works for you? If it works OK, I will update the pypi repository.

Great! That works 👍

1. How did you find out about this mermaid>callback argument for the mermaid.initialize() function? I could not find any mention about this on the official website.

Hmm, I can’t recall. Probably from examples in the wild, or Mermaid issues.

1. For the record (not tested and no idea whether this could possibly be useful): instead of a javascript function name, would it be possible to write its code directly, something like.

Sure, I think that’d be nice for all those users who don’t plan to add any other custom JS.