Question

I am trying to build a simple Bookmarklet that will load some external Javascript into a page, the goal is to add a markdown editor like Stackoverflow has to another site. I have it working but it requires me to click my Bookmarklet button 2 times instead of 1 time.

The first click gives this error…

Uncaught ReferenceError: Markdown is not defined init.js:46

Line 46 is this…

var converter1 = Markdown.getSanitizingConverter();

Now after clicking my Bookmarklet for the 2nd time then everything runs perfectly but always the first click will give that error and do nothing.

Here is the code for the Bookmarklet file, please help me to fix, my Javascript skills are not too great.

Load external JS and CSS files

function loadScripts(scriptURL) {
    var scriptElem = document.createElement('SCRIPT');
    scriptElem.setAttribute('language', 'JavaScript');
    scriptElem.setAttribute('src', scriptURL);
    void(document.body.appendChild(scriptElem));
}

// Load these 3 Javascript files into the page
// jQuery is already loaded into the page being used so no need to load it
loadScripts('http://codedevelopr.com/labs/javascript/forrst/Markdown.Converter.js');
loadScripts('http://codedevelopr.com/labs/javascript/forrst/Markdown.Sanitizer.js');
loadScripts('http://codedevelopr.com/labs/javascript/forrst/Markdown.Editor.js');

// Load the CSS file into the Page
var head = document.getElementsByTagName('head')[0];
$(document.createElement('link')).attr({
    type: 'text/css',
    href: 'http://codedevelopr.com/labs/javascript/forrst/demo.css',
    rel: 'stylesheet'
}).appendTo(head);

After the files are loaded then we run this…

// Find and replace the curent textarea with the HTML we
// need for our markdown editor to work 
$(document).ready(function () {
    var htmlToReplace = ' \
  <div class="wmd-panel"> \
    <div id="wmd-button-bar"></div> \
      <textarea class="wmd-input" id="wmd-input" name="description"></textarea> \
  </div> \
  <div id="wmd-preview" class="wmd-panel wmd-preview"></div>';

    $("#description").replaceWith(htmlToReplace);

    //Run the Markdown editor!
    var converter1 = Markdown.getSanitizingConverter();

    var editor1 = new Markdown.Editor(converter1);
    editor1.run();

});

Answer 1

Your script files are not loaded yet at the time you’re using markdown. You’ve merely sent the requests. You have to wait until the response is received and parsed.

I’ve cleaned your code up a bit as well as you’re using jQuery:

var urls = [
  'http://codedevelopr.com/labs/javascript/forrst/Markdown.Converter.js',
  'http://codedevelopr.com/labs/javascript/forrst/Markdown.Sanitizer.js',
  'http://codedevelopr.com/labs/javascript/forrst/Markdown.Editor.js'
];

// map urls to getScript calls, and pass them to $.when
$.when.apply($, $.map(urls, $.getScript)).then(function() {
  // use markdown here
});

$("<link>", {
  href: 'http://codedevelopr.com/labs/javascript/forrst/demo.css',
  rel: 'stylesheet'
}).appendTo("head");