Here's your reason, basically the theming changes in D7 mean the field theming gets bound a lot lot later in the process, so it's not possible to generate the output into a Textarea for you to edit - that said, it is possible that we can come at this from another angle and use tokens instead BUT it means what you see in contemplate admin page will be nothing at all similar to the output.
The Content Template (a.k.a. ConTemplate) module allows modification of Drupal's teaser and body fields using administrator defined templates. These templates use PHP code and all of the node object variables are available for use in the template. An example node object is displayed and it is as simple as clicking on its properties to add them to the current template.
This module aims to provide a full implementation of the Gallery project's Gallery Remote Protocol in order to support publishing images using Drupal's Image module.
As of October 9, 2020, this project appears to be no longer supported. If, as the project maintainer, you feel this message has been posted in error, please post a comment on #857614: Is Coolfilter still being maintained?.
This module allows you to use HTML-like tags as an alternative to HTML itself for adding almost any type of media to your posts for most of modern browsers both in windows & linux easily.
