Editing HTML inside Drupal

Drupal does not provide a good environment for authoring Exhibit HTML for technical and workflow reasons.

Using Github Gists as an HTML Editor

Using Github Gists provides an easy, web-accessible, version-controlled way to edit and save HTML fragments. For Exhibit-powered pages, just edit and save the page in a Gist. When you make changes, paste them into the Drupal editor.

If you really want to try HTML editing in Drupal

• Navigate to Home » Administration » Configuration » Content authoring » Wysiwyg profiles
• Edit the Full HTML settings.
• Under Cleanup and Output, disable "Remove Linebreaks"
• Under Cleanup and Output, disable "Apply source formatting"

...but there is a catch

Saving HTML in the Drupal is not idempotent. So if you re-edit an HTML Drupal post, the Exhibit will no longer render properly. This is because Drupal, like many HTML editors, take liberties with whitespace, which is usually semantically irrelevant. Unfortunately, Exhibit does place meaning in whitespace, meaning that re-shuffling the spacing of HTML elements can break an Exhibit.

Takeaway: Use Github Gists.