This plugin is responsible for translating TML to HTML before an edit starts
and translating the resultant HTML back into TML.
Note: In the case of a new topic, you might expect to see the "create topic"
screen in the editor when it goes back to Foswiki for the topic content. This
doesn't happen because the earliest possible handler is called on the topic
content and not the template. The template is effectively ignored and a blank
document is sent to the editor.
Attachment uploads can be handled by URL requests from the editor to the rest
handler in this plugin. This avoids the need to add any scripts to the bin dir.
You will have to use a form, though, as XmlHttpRequest does not support file
StaticMethod notWysiwygEditable($text) → $boolean
Determine if the given $text is WYSIWYG editable, based on the topic content
and the value of the Foswiki preferences WYSIWYG_EXCLUDE and
WYSIWYG_EDITABLE_CALLS. Returns a descriptive string if the text is not
editable, 0 otherwise.