讲解CO539留学生、辅导SQL、讲解MVC framework、辅导SQL语言程序

CO539 Coursework 1

Introduction

Microblog Site

For this piece of Coursework, you are going to use the CodeIgniter MVC framework introduced in lectures to create a simple microblog (forum) website, covering some of the basic functionality offered by twitter/facebook et al. To help you, we have created a database with all of the tables you will require, along with some seed data to get you started. The coursework is split into three parts.

In the first part, you will create functionality allowing the messages sent by a particular user

to be viewed, and create the site’s search function.

In the second part, you will add the functionality required to allow users to login, and to post messages.

In the third part, you will add the functionality required to allow users to follow other users, and to view a combined feed of messages posted by everybody they follow.

10% of the marks are available for your site’s design and code quality. This covers both the visual appearance of the site, and how concise, well laid out and well commented your code is.

To start, you will need to install the CodeIgniter framework, which is available at http://www.codeigniter.com/ . You will also need a copy of the initial database, which is available via a link on Moodle. Import the sample database into your personal MySQL database on dragon (using the mysql command) and unzip CodeIgniter into its destination folder (strongly recommended to be your submission directory), configuring it following its install instructions.

The Database

The database consists of three tables: Users, Messages, and User_Follows. The Users table contains the login details of each of the site’s users, including an SHA1-hashed password. The Messages table contains all of the messages users have posted, using the poster’s username as a foreign key. The User_Follows table stores “who follows who”, using the username of both the following and followed user as foreign keys. A database diagram illustrating the tables, their fields and the relationships between them is pictured below.

Figure 1: Entity-Relation Model for the Supplied Database

The database has been pre-populated with some users, messages and followers. The password for each user is “password”, which will be useful for testing purposes, and deliciously insecure.

Part I – Basic Functionality (30%)

Visiting your site with /user/view/kris URL segments should display all of the messages posted by user “kris” whereas visiting /user/view/ben should do likewise for “ben”

Visiting your site with a /search URL segment should display a search form. Entering a search string into the form should retrieve all the messages containing that term. The search form should submit to the search/dosearch action, passing the search string via GET.

Design

Models

Model NameFunction nameDescription

Messages_modelgetMessagesByPoster($name)Returns all messages posted by the user with

the specified username, most recent first

Messages_modelsearchMessages($string)Returns all messages containing the specified

search string, most recent first

Controllers

Controller NameAction NameDescription

Userview($name)Loads Messages_model, runs getMessagesByPoster()

passing the specified name, and displays output in the

ViewMessages view

Searchindex()Displays the Search view

Searchdosearch()Loads Messages_model, retrieves search string from GET

parameters, runs searchMessages() and displays the

output in the ViewMessages view

Views

View NameDescription

ViewMessagesDisplays a list of messages, with details of poster, content and time of each

message. Poster’s name should be linked to the user/view/{poster} for that

user

SearchDisplays a form with a search box, in which the user can enter search

terms. The form should submit to /search/dosearch via GET

Part II - Logging in & Posting (40%)

Users should be able to login and logout from the site using their credentials. The login page should be at user/login and the logout page at user/logout. N.B. Users do not need to login to view messages or search.

Once logged in, a user should be able to post a message by visiting the /message page

Design

Models

Model NameFunction nameDescription

Users_modelcheckLogin($username,$pass)Returns TRUE if a user exists in the database

with the specified username and password,

and FALSE if not.

Note: passwords in the database are SHA1

hashed, so hash supplied passwords before

searching the database

Messages_modelinsertMessage($poster, $string)Adds the supplied message to the messages

table in the database

Controllers

Controller NameAction NameDescription

Userlogin()Displays the Login view

UserdoLogin()Loads the Users_model, calls checkLogin() passing

POSTed user/pass & either re-displays Login view with

error message, or redirects to the user/view/{username}

controller to view their messages. If login is successful, a

session variable containing the username is set.

Userlogout()Logs the user out, clearing their session variable, and

redirects to /user/login

Messageindex()Redirects to /user/login if not logged in.

Displays the Post view

MessagedoPost()Redirects to /user/login if not logged in.

Loads the Messages_model, runs the insertMessage

function passing the currently logged in user from your

session variable, along with the posted message.

Redirects to /user/view/{username} when done, which

should show the user’s new post

Views

View NameDescription

LoginDisplays a login form for a user to supply their username and password.

This form should submit via POST to /user/dologin

PostDisplays a form in which the user can write a new post. This form should

submit via POST to the /message/doPost action

Part III – Following Others (20%)

When viewing another users /user/view/{username} page, and if currently logged in, a “Follow” button should appear, allowing the currently logged in user to follow this user

There should be a /user/feed/{username} page that views all of the messages, from all of the users followed by the specified user

Design

Models

Model NameFunction nameDescription

Messages_modelgetFollowedMessages($name)Returns all of the messages from all of those

followed by the specified user, most recent

first

Users_modelisFollowing($follower,$followed)Returns TRUE if $follower is following

$followed, FALSE otherwise

Users_modelfollow($followed)Inserts a row into the Following table

indicating that the logged-in user follows

$followed

Controllers

Controller NameAction NameDescription

Userview($name)This action will need modifying to add a “follow”

button or link if, after loading Users_model, the

isFollowing() function indicates the currently logged

in user (from your login session variable) isn’t

following the viewed user. This link should point to

user/follow/

Userfollow($followed)Loads the Users_model, and invokes the follow()

function to add the entry into the database table.

Should redirect back to the /user/view/{followed}

page when done

Userfeed($name)Loads the Messages_model, invokes the

getFollowedMessages() function, and puts the

output into the ViewMessages view.

Design & Code Quality (10%)

Although the suggested design in each of the previous sections will, if implemented correctly, be enough to get you a working micro-blogging site, it won’t be particularly user friendly. For example, there won’t be links atop each page to the login/logout pages, your own page, and your feed. To score well in this section, give some thought to both usability and visual design, and turn your coursework into a site people could actually use. Your code should be well laid out, commented, and readily maintainable.