@onereach/webform/src/utils/slimdown.js

Content Builder includes several views for: - Content builder view itself; - Web Form view; - Slack block-kit builder;

'use strict';

/**
 * Javascript version of https://gist.github.com/jbroadway/2836900
 *
 * Slimdown - A very basic regex-based Markdown parser. Supports the
 * following elements (and can be extended via Slimdown::add_rule()):
 *
 * - Headers
 * - Links
 * - Bold
 * - Emphasis
 * - Deletions
 * - Quotes
 * - Inline code
 * - Blockquotes
 * - Ordered/unordered lists
 * - Horizontal rules
 *
 * Author: Johnny Broadway <johnny@johnnybroadway.com>
 * Website: https://gist.github.com/jbroadway/2836900
 * License: MIT
 */
export default function Slimdown() {
  // Rules
  this.rules = [
    { regex: /(#+)(.*)/g, replacement: header }, // headers
    {
      regex: /!\[([^\[]+)\]\(([^\)]+)\)/g,
      replacement: "<img src='$2' alt='$1'>"
    }, // image
    { regex: /\[([^\[]+)\]\(([^\)]+)\)/g, replacement: "<a href='$2'>$1</a>" }, // hyperlink
    { regex: /(\*\*|__)(.*?)\1/g, replacement: '<strong>$2</strong>' }, // bold
    { regex: /(\*|_)(.*?)\1/g, replacement: '<em>$2</em>' }, // emphasis
    { regex: /\~\~(.*?)\~\~/g, replacement: '<del>$1</del>' }, // del
    { regex: /\:\"(.*?)\"\:/g, replacement: '<q>$1</q>' }, // quote
    { regex: /`(.*?)`/g, replacement: '<code>$1</code>' }, // inline code
    { regex: /\n\*(.*)/g, replacement: ulList }, // ul lists
    { regex: /\n[0-9]+\.(.*)/g, replacement: olList }, // ol lists
    { regex: /\n(&gt;|\>)(.*)/g, replacement: blockquote }, // blockquotes
    { regex: /\n-{5,}/g, replacement: '\n<hr />' }, // horizontal rule
    { regex: /\n([^\n]+)\n/g, replacement: para }, // add paragraphs
    { regex: /<\/ul>\s?<ul>/g, replacement: '' }, // fix extra ul
    { regex: /<\/ol>\s?<ol>/g, replacement: '' }, // fix extra ol
    { regex: /<\/blockquote><blockquote>/g, replacement: '\n' } // fix extra blockquote
  ];

  // Add a rule.
  this.addRule = function(regex, replacement) {
    regex.global = true;
    regex.multiline = false;
    this.rules.push({ regex: regex, replacement: replacement });
  };

  // Render some Markdown into HTML.
  this.render = function(text) {
    text = '\n' + text + '\n';
    this.rules.forEach(function(rule) {
      text = text.replace(rule.regex, rule.replacement);
    });
    return text.trim();
  };

  function para(text, line) {
    var trimmed = line.trim();
    if (/^<\/?(ul|ol|li|h|p|bl)/i.test(trimmed)) {
      return '\n' + line + '\n';
    }
    return '\n<p>' + trimmed + '</p>\n';
  }

  function ulList(text, item) {
    return '\n<ul>\n\t<li>' + item.trim() + '</li>\n</ul>';
  }

  function olList(text, item) {
    return '\n<ol>\n\t<li>' + item.trim() + '</li>\n</ol>';
  }

  function blockquote(text, tmp, item) {
    return '\n<blockquote>' + item.trim() + '</blockquote>';
  }

  function header(text, chars, content) {
    var level = chars.length;
    return '<h' + level + '>' + content.trim() + '</h' + level + '>';
  }
}