From: chapel Date: Sat, 5 Nov 2011 06:25:41 +0000 (-0700) Subject: Overview write-up of backchannel server X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=e68a893884902bdb7010729ad1c84b8bc191445b;p=oweals%2Ffinalsclub.git Overview write-up of backchannel server --- diff --git a/app.js b/app.js index 5d8860d..56350b9 100644 --- a/app.js +++ b/app.js @@ -1638,6 +1638,83 @@ app.get( '/archive/note/:id', loadUser, function( req, res ) { // socket.io server +// The finalsclub backchannel server uses socket.io to handle communication between the server and +// the browser which facilitates near realtime interaction. This allows the user to post questions +// and comments and other users to get those almost immediately after they are posted, without +// reloading the page or pressing a button to refresh. +// +// The server code itself is fairly simple, mainly taking incomming messages from client browsers, +// saving the data to the database, and then sending it out to everyone else connected. +// +// Data types: +// Posts - Posts are the main items in backchannel, useful for questions or discussion points +// Comments - Comments are replies to posts, for clarification or answering questions +// Votes - Votes signifyg a users approval of a post +// Flags - Flagging a post signifies that it is against the rules, 2 flags moves it to the bottomw +// +// +// Post Schema +// body - Main content of the post +// userId - Not currently used, but would contain the users id that made the post +// userName - Users name that made post +// userAffil - Users affiliation to their school +// public - Boolean which denotes if the post is public to everyone, or private to school users only +// date - Date post was made, updates when any comments are made for the post +// comments - An array of comments which contain a body, userName, and userAffil +// votes - An array of user ids which are the users that voted +// reports - An array of user ids which are the users that reported the post +// +// Posts and comments can be made anonymously. When a post is anonymous, the users info is stripped +// from the post and the userName is set to Anonymous and the userAffil to N/A. This is to allow +// users the ability to make posts or comments that they might not otherwise due to not wanting +// the content of the post/comment to be attributed to them. +// +// Each time a user connects to the server, it passes through authorization which checks for a cookie +// that is set by Express. If a session exists and it is for a valid logged in user, then handshake.user +// is set to the users data, otherwise it is set to false. handshake.user is used later on to check if a +// user is logged in, and if so display information that otherwise might not be visible to them if they +// aren't apart of a particular school. +// +// After the authorization step, the client browser sends the lecture id which is rendered into the html +// page on page load from Express. This is then used to assign a 'room' for the user which is grouped +// by lecture. All posts are grouped by lecture, and only exist for that lecture. After the user is +// grouped into a 'room', they are sent a payload of all existing posts for that lecture, which are then +// rendered in the browser. +// +// Everything else from this point on is handled in an event form and requires a user initiating it. The +// events are as follows. +// +// Post event +// A user makes a new post. A payload of data containing the post and lecture id is sent to the server. +// The server recieves the data, assembles a new post object for the database and then fills it with +// the appropriate data. If a user selected for the post to be anonymous, the userName and userAffil are +// replaced. If the user chose for the post to be private, then public will be set to false and it +// will be filtered from being sent to users not logged into and not having access to the school. Once +// the post has been created and saved into the database, it is sent to all connected users to that +// particular lecture, unless it is private, than only logged in users will get it. +// +// Vote event +// A user votes for a post. A payload of data containing the post id and lecture id are sent along with +// the user id. A new vote is created by first fetching the parent post, then adding the user id to the +// votes array, and then the post is subsequently saved back to the database and sent to all connected +// users unless the post is private, which then it will be only sent to logged in users. +// +// Report event +// Similar to the vote event, reports are sent as a payload of a post id, lecture id, and user id, which +// are then used to fetch the parent post, add the user id to the reports array, and then saved to the db. +// Then the report is sent out to all connected users unless it is a private post, which will be only sent +// to logged in users. On the client, once a post has more two (2) or more reports, it will be moved to the +// bottom of the interface. +// +// Comment event +// A user posts a comment to a post. A payload of data containing the post id, lecture id, comment body, +// user name, and user affiliation are sent to the server, which are then used to find the parent post +// and then a new comment object is assembled. When new comments are made, it updates the posts date +// which allows the post to be sorted by date and the posts with the freshest comments would be pushed +// to the top of the interface. The comment can be anonymous, which then will have the user +// name and affiliation stripped before saving to the database. The comment then will be sent out to all +// connected users unless the post is private, then only logged in users will recieve the comment. + var io = require( 'socket.io' ).listen( app ); var Post = mongoose.model( 'Post' );