Leave comments on someone elses pages #47

These page contains details for the implementation of the comments section for BookStack. Issue is [here] (https://github.com/ssddanbrown/BookStack/issues/47).

Functionality to implement

• Add a simple editor with Markdown support.
• Ability to add comments.
• Ability to edit own comments.
• Ability to delete your own comments
• Ability to link directly to a comment in the page
• Ability to reply to a comment (upto 2 levels?)
• Display total comments on the page summary maybe.
• User should not be able to edit other's comments.

Future enhancements

• Comment change history
• Add roles to comment.
• Inline document comments where users can highlight sections of pages and comment on those.
• Like comments
• Highlight people via your comments with a "@Abijeet", similar to Facebook.

Database schema

The database schema will be a simple tree based schema.

Reviewed various tree based schema's structure for SQL described here http://mikehillyer.com/articles/managing-hierarchical-data-in-mysql/

After analyzing the various schema structures, I've finally decided to go ahead with the Adjacency List based on its simplicity. Following will be the schema structure -