kaavio-showdown-syntax1.js

var parse = require('s-expression');
var showdown = require('showdown');

function zoomOn(nodes) {
  console.log('zoomOn');
  console.log(`nodes: ${nodes}`);
}

function toggleHighlight(node, color) {
  console.log('toggleHighlight');
  console.log(`node: ${node}`);
  console.log(`color: ${color}`);
}

var manipulations = {
  zoomOn: zoomOn,
  toggleHighlight: toggleHighlight,
};

var combinations = new Map();

showdown.extension('myExtension', function() {
    return {
      type: 'lang',
      filter: function (text, converter, options) {
        return text.replace(/(\[)(.*)(\])(!!)(.*)(!!)/g, function(match, titleDelimStart, title, titleDelimEnd, exprDelimStart, exprs, exprDelimEnd, str) {
            var eventArr = parse(exprs)
                .reduce(function(acc, expr) {
                    if (typeof expr === 'string') {
                        acc.push({
                            fn: expr,
                            args: []
                        });
                    } else {
                        acc[acc.length - 1].args.push(expr);
                    }
                    return acc;
                }, []);

                var eventArrStr = JSON.stringify(eventArr).replace(/[^a-zA-Z0-9]/g, '');

                combinations.set(eventArrStr, function() {
                    eventArr.forEach(function(x) {
                        manipulations[x.fn].apply(undefined, x.args);
                    });                    
                });
            return `<p onClick="combinations.get(${eventArrStr})">${title}</p>`;
        });
      }
    };
});
  
var converter = new showdown.Converter({ extensions: ['myExtension'] });

const input = '[some text]!!(zoomOn (node1 node2 node3) toggleHighlight (node2 red) (node3 yellow))!!';
var html = converter.makeHtml(input);
console.log(html);