clj-forum

~~Live Demo~~ (Offline)

I'm figuring things out and yak-shaving as I go.

(I'm particularly inexperienced with Datomic)

Features

Implemented/somewhat implemented:

Conventional forums <-- topics <-- posts relationship
Roles: :admin, :mod, :member, :banned, :guest
Avatars. Users are randomly generated one upon registration (randomly-colored square)
Admin/mod/users share a single interface. http://gettingreal.37signals.com/ch09_One_Interface.php
Post permalinks
Debug toolbar. Ex: Shows the full request map
Live Markdown preview on New Topic and New Post forums (same Markdown parser on server and client)
CSRF protection

Planned:

Homepage

Markdown preview

Moderator tools

Debug toolbar

Download latest Datomic-free
cd into it
Uncomment the dev laptop settings in config/samples/free-transactor-template.properties

Run the transactor in its own terminal:

  bin/transactor -Xmx1g config/samples/free-transactor-template.properties

(Run tests with lein autoexpect)

The flow:

Routes in forum.handler send params to a controller in forum.controllers.*.
A controller make DB calls and (unimplemented:) authorizes access, then passes values to a view in forum.views.*.
Views are just Hiccup datastructures.

Middleware:

forum.middleware.expose-request binds a dynamic var req that any namespace can refer to if they want to see the full Ring request-map. Ideally, req will be broken up into more specific functions/vars sort of like this next middleware:
forum.middleware.wrap-current-user binds a dynamic var current-user that either contains the DB entity of a user ({:user/uname "kate", :user/digest "abc", :user/topics [...], :user/posts [...], ...}) or nil if there is no user logged in. It reads this data from the session.

Session:

forum.controllers.sessions is the controller used in the login/logout flow. It creates a session or sets it to nil.
The session is stored in an encrypted cookie that's signed by an application-unique :session-secret that should be defined in resources/config.edn. The secret should be >= 16 bytes (minimum necessary for the AES key).

Database attributes:

User

:user/uname - username
:user/digest - plaintext salt concatenated with hashed password (then converted to base64)
:user/topics - refs of the topics the user has created
:user/posts
:user/created - when user was created
:user/uid - unique id of user that's autoincremented on creation. the preferred lookup attribute.
:user/role - either :admin or :mod (:member and :guest are not stored in the database. A :member is {:user/uid _, ...} without a given role. A :guest is a user with no :user/uid -- a user that's not saved in the database.)

Forum

Topic

The OP's post in a topic is simply the first post (sorted by uid ascending). A topic is just a titled collection of posts.

Post