Calling markdownit() for a dynamically loaded div

<!doctype html>
<html>
<head>

<script src="https://cdnjs.cloudflare.com/ajax/libs/markdown-it/13.0.1/markdown-it.min.js" integrity="sha512-SYfDUYPg5xspsG6OOpXU366G8SZsdHOhqk/icdrYJ2E/WKZxPxze7d2HD3AyXpT7U22PZ5y74xRpqZ6A2bJ+kQ==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>


<script>
window.onload = function() {
  var md = window.markdownit();
  var div = document.getElementsByClassName('markdown');
  for(var i = 0; i < div.length; i++) {
    var content = div[i].innerHTML;
    document.getElementsByClassName('markdown')[i].innerHTML = md.render(content);
  }
}
</script>

</head>
<body>


<div class="markdown">
# h1 Heading
## h2 Heading
### h3 Heading
#### h4 Heading
##### h5 Heading
###### h6 Heading

+ one
+ two
  + two and half
+ three
  + three and half
    + three point seventy five
</div>

</body>
</html>

This is an example of how to call markdownit() for a specific div after the page loads.

On my page, div tags are loaded dynamically after certain user actions. How do I call markdownit() for an emerging div with the id="markdown" attribute?

Solution

You can achieve this by simply moving your code into a separate function, then call that function whenever user submit new content.

var md = window.markdownit();

function markdownContent() {
  var div = document.getElementsByClassName('markdown');
  for(var i = 0; i < div.length; i++) {
    // Check if it is already loaded, if not, add attribute as loaded
    if(div[i].hasAttribute('markdown-loaded')) continue;
    div[i].setAttribute('markdown-loaded', '');

    var content = div[i].innerHTML;
    document.getElementsByClassName('markdown')[i].innerHTML = md.render(content);
  }
}

window.onload = function() {
  markdownContent();
}

Example:

<!doctype html>
<html>
<head>

<script src="https://cdnjs.cloudflare.com/ajax/libs/markdown-it/13.0.1/markdown-it.min.js" integrity="sha512-SYfDUYPg5xspsG6OOpXU366G8SZsdHOhqk/icdrYJ2E/WKZxPxze7d2HD3AyXpT7U22PZ5y74xRpqZ6A2bJ+kQ==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>

  <style>
    textarea {
      display: block;
      margin-bottom: 5px;
      width: 100%;
      max-width: 300px;
      height: 90px;
    }
  </style>

<script>
var md = window.markdownit();

function markdownContent() {
  var div = document.getElementsByClassName('markdown');
  for(var i = 0; i < div.length; i++) {
    // Check if it is already loaded, if not, add attribute as loaded
    if(div[i].hasAttribute('markdown-loaded')) continue;
    div[i].setAttribute('markdown-loaded', '');

    var content = div[i].innerHTML;
    document.getElementsByClassName('markdown')[i].innerHTML = md.render(content);
  }
}

window.onload = function() {
  markdownContent();

  const markdownInput = document.querySelector('.markdown-user-input');
  const markdownSubmitButton = document.querySelector('.submit-markdown');
  const markdownOutput = document.querySelector('.dynamic-markdown');

  markdownSubmitButton.addEventListener('click', () => {
    if(!markdownInput.value) return void 0;

    markdownOutput.innerHTML = `<div class="markdown">\n${markdownInput.value}\n</div>`;
    markdownContent();
  });

}
</script>

</head>
<body>
<h1 style="color: rgb(104, 104, 104);">Try editing and submit to see dynamic markdown updation.</h1>
<textarea class="markdown-user-input">
# Try Submitting Markdown
## Example of an H2 Heading

- List item
</textarea>
<button class="submit-markdown">Submit Markdown</button>

<h2 style="color: rgb(104, 104, 104);">Rendered Markdown Output</h2>
<div class="dynamic-markdown"></div>

<hr>

<h1 style="color: rgb(104, 104, 104);">Default Markdown Loaded</h1>
<div class="markdown">
  # H1 Heading Example
  ## H2 Heading Example
  ### H3 Heading Example
  #### H4 Heading Example
  ##### H5 Heading Example
  ###### H6 Heading Example
  
  + Item One
  + Item Two
    + Subitem Two
  + Item Three
    + Subitem Three
      + Deeper Subitem
</div>

</body>
</html>