How do I set the auto-open for inline preview for Files using the Rich Content Editor?
You can use the auto-open inline preview for Files in the Rich Content Editor.
Open the Rich Content Editor
Open the Rich Content Editor using one of the Canvas features which support the Editor.
Locate Content Selector
The Content Selector will automatically open when the Rich Content Editor is opened.
Open URL Link Icon
Insert the file. Make sure the cursor is in the file link somewhere . Click the URL link icon  to open a pop-up window.
Enable Auto-Open for Inline Preview
Click the Auto-open the inline preview for this link checkbox . Then click on Update Link .
Note: You can have multiple files auto-open, but you have to go through the steps in this lesson every time you want to add another auto-open file preview in a feature that uses the Rich Content Editor.
View Auto-Opened File
View the auto-opened file.