Rails Web App Learning in action (1)–the basic version of students selective courses

TThis tutorial is based on the postgraduate course, named software development methodology, from University of Chinese Academy of Sciences. This tutorial can help you generate a basic version of the final project. At first, you must set up Rails environment successfully and run the basic framework. Secondly, you can add more functions based on it. We will continue supply guidance for your following project. The code of the basic version of the Demo in this tutorial has been uploaded to Github already. This tutorial is helpful for new developers of Ruby on Rails to add the following new functions on the basic version:

• Deal with course conflict and control the student number
• Count credit points, degree course, etc.
• Add the function of opening and closing the selective courses system.
• Customize administrator backstage
• Authorized login based on OAuth
• Data input in Excel format
• Bind user’s mailbox (to achieve the function of register activation,forgot password, etc.)
• Search and retrieval within the site (such as searching courses
  according to the classification)

Installation environment

Compared with other languages for Web development, Rails requires the developer to possess more relevant professional knowledge, for the reason that the construction of local development environment for Rails is relatively tough, especially under Windows system. For other system, such as Mac OS and Linux, the situation is better. Hence this tutorial is on basis of Linux system or Mac system.

Local

1.Ubantu 14.04

Install via rbenv–tutorial
Install via RVM–tutorial

2.Mac OS

Similar to Ubantu –tutorial

Cloud IDE (integrated development environment)

In addition to the construction of local environment, you can also choose cloud IDE (integrated development environment) such as Cloud9 IDE. Using cloud IDE can be exempted from the trouble of setting up local environment. As long as you can surf the Internet, the computer can access cloud IDE through the webpage, and you can edit and run the code online. But this ease of use comes with a drawback: The IDE of cloud editor is not as strong as the download IDE of local. For example, RubyMine of Jetbeans company is the most intelligent IDE of Ruby so far, which can rival Eclipse and Netbeans of J ava. Besides, Jetbeans company also provide PyCharm for Python and PHPStorm for PHP language. They are all very good integrated development environment, which can add breakpoints to debug your applications, correct code automatically and layout automatically, etc. The good news is that students and teachers can use them for free for one year via applying by school email.

Running instances

1.We take the development of Cloud9 as example. After you register and login, you will see the following interface:

2.Clicking “create a new workspace”, it will jump to the following page:

Note: Please write the branch URL behind fork in the website of Clone from Git. For instance, https://github.com/your account name of github /CourseSelect. Write project name and choose Ruby as the project language, then you can click to create new workspace.

3.Enter the page of editing IDE:

On the left is project directory and on the right is the window for editing files. The terminal at its lower right is for entering the command line.

4.Enter bundle install in terminal and install external libraries required by project, which is called as Gems by Rails. When you see following result, that means all libraries we need are installed completely:

pengzhaoqing:~/workspace (master) $ bundle installFetching gem metadata from https://gems.ruby-china.org/...........Fetching version metadata from https://gems.ruby-china.org/..Using rake 11.2.2Using i18n 0.7.0Using json 1.8.3Using minitest 5.9.0Using thread_safe 0.3.5Using builder 3.2.2Using erubis 2.7.0Using mini_portile2 2.1.0Using pkg-config 1.1.7Using rack 1.6.4Using mime-types-data 3.2016.0521Using arel 6.0.3Using execjs 2.7.0Installing bcrypt 3.1.11 with native extensionsUsing debug_inspector 0.0.2Using sass 3.4.22Using byebug 9.0.5Using coffee-script-source 1.10.0Using thor 0.19.1Using concurrent-ruby 1.0.2Using tilt 2.0.5Using multi_json 1.12.1Installing nested_form 0.3.2Installing pg 0.18.4 with native extensionsUsing bundler 1.12.5Installing rails_serve_static_assets 0.0.5Installing rails_stdout_logging 0.0.5Installing remotipart 1.2.1Installing safe_yaml 1.0.4Using spring 1.7.2Using turbolinks-source 5.0.0Installing faker 1.6.3Using rdoc 4.2.2Using tzinfo 1.2.2Using nokogiri 1.6.8Using rack-test 0.6.3Using mime-types 3.1Installing autoprefixer-rails 6.4.0.2Installing uglifier 3.0.1Using binding_of_caller 0.7.2Using coffee-script 2.4.1Using sprockets 3.7.0Installing haml 4.0.7Installing rails_12factor 0.0.3Using turbolinks 5.0.1Using sdoc 0.4.1Installing activesupport 4.2.5.2Using loofah 2.0.3Installing rack-pjax 0.8.0Using mail 2.6.4Installing bootstrap-sass 3.3.7Using rails-deprecated_sanitizer 1.0.3Using globalid 0.3.7Installing activemodel 4.2.5.2Using jbuilder 2.6.0Using rails-html-sanitizer 1.0.3Using rails-dom-testing 1.0.7Installing activejob 4.2.5.2Installing activerecord 4.2.5.2Installing actionview 4.2.5.2Installing actionpack 4.2.5.2Installing actionmailer 4.2.5.2Installing railties 4.2.5.2Installing kaminari 0.16.3Using sprockets-rails 3.1.1Using coffee-rails 4.1.1Installing font-awesome-rails 4.5.0.1Installing jquery-rails 4.1.1Installing jquery-ui-rails 5.0.5Installing rails 4.2.5.2Using sass-rails 5.0.6Using web-console 2.3.0Installing rails_admin 0.8.1Bundle complete! 17 Gemfile dependencies, 73 gems now installed.Use `bundle show [gemname]` to see where a bundled gem is installed.Post-install message from haml:HEADS UP! Haml 4.0 has many improvements, but also has changes that may breakyour application:* Support for Ruby 1.8.6 dropped* Support for Rails 2 dropped* Sass filter now always outputs <style> tags* Data attributes are now hyphenated, not underscored* html2haml utility moved to the html2haml gem* Textile and Maruku filters moved to the haml-contrib gemFor more info see:http://rubydoc.info/github/haml/haml/file/CHANGELOG.md

5.Originally, the default database inside Rails is Sqlite3 and you do not need to install it. However, we use postgresql database in this project, for better matching Heroku in later period. Fortunately, Cloud9 has installed Postgresql database already, so we just need to enter sudo service Postgresql start in the terminal, and then Postgresql database will be started.

At this point if we build the table directly, there will generate coding error: PG: : Error: Error: the new encoding UTF8) is incompatible, according to this. According to there, we will run the following code line by line in terminal to solve above problem:

// enter postgresql databasepengzhaoqing:~/workspace (master) $ psqlpsql (9.3.14)Type "help" for help.ubuntu=# UPDATE pg_database SET datistemplate = FALSE WHERE datname = 'template1';UPDATE 1ubuntu=# DROP DATABASE template1;DROP DATABASEubuntu=# CREATE DATABASE template1 WITH TEMPLATE = template0 ENCODING = 'UNICODE';CREATE DATABASEubuntu=# UPDATE pg_database SET datistemplate = TRUE WHERE datname = 'template1';UPDATE 1ubuntu=# \c template1You are now connected to database "template1" as user "ubuntu".template1=# VACUUM FREEZE;VACUUMtemplate1-# \q

6.After the database is ready, we establish the table by the following instructions:

pengzhaoqing:~/workspace (master) $ rake db:create:all

Then migrating data:

pengzhaoqing:~/workspace (master) $ rake db:migrate== 20160818081955 CreateUsers: migrating ======================================-- create_table(:users)   -> 0.0328s-- add_index(:users, :email, {:unique=>true})   -> 0.0081s== 20160818081955 CreateUsers: migrated (0.0412s) =============================== 20160907152104 CreateCourses: migrating ====================================-- create_table(:courses)   -> 0.0117s== 20160907152104 CreateCourses: migrated (0.0118s) ============================= 20160909105514 CreateGrades: migrating =====================================-- create_table(:grades)   -> 0.0192s== 20160909105514 CreateGrades: migrated (0.0194s) ============================

At last, writing seed data:

pengzhaoqing:~/workspace (master) $ rake db:seed

7.Click Run Project button in IDE, then the URL of the website can be seen in log. You can click this URL to enter the project presentation page:

End

Now, this program run successfully. You can find more details about this project here. Next time I will decompose this project and write from very beginning.

If you think this program is good, please click the star for this program in the top right corner of Github page~