Workbook

XML and Web Services >> Workbook

Ruby install on a USB stick

1. Download the One-click ruby installer from rubyforge http://rubyforge.org/frs/?group_id=167 (warning this is a big file!). The one I used was ruby186-25.exe but there may be a later version available. To be able to run the whole environment from a USB stick I’d really recommend you have about 500MB free (maybe it’s time to buy a new stick?)
2. Double-click on the installer, after clicking next a few times, a screen like the one shown below is displayed.
3. Ensure you install on your USB stick, not the C drive (check the drive letter, as shown. Mine is J:, yours may vary)
4. Once Ruby is installed, open a cmd prompt (enter cmd into the ‘run’ box from the start menu) change to your ruby directory (e.g. j:\ruby ) and enter the follow command:
5. gem install rails -y
6. You may need to add the ruby directory to your system path, the setenv.bat file discussed in class will do this – the command is:
7. set path=%PATH%;j:\ruby\bin;
   1. Remember to change the drive letter (j: in the example above) to match the letter assigned to your USB stick. This will probably be different for each system – it’s a windows foible – what a wonderful system :) (maybe you should try Linux? – ok Rant over.) This is why we suggested in the lecture that you put the command above in its own file, which we called setenv.bat, so that it’s easy to change.
8. The gem command should install rails, see below for a database.

Exercises

Create one (or more) programs using ruby that can perform the following tasks:

1. Create a program that can take a phrase as input and print it out in reverse.
2. Create a program that can take a phrase as input and output it’s length as a number
3. Create an application that can encrypt any phrase you enter using the rot13 algorithm
4. Create an application that can take a temperature in F or C and convert to the other form

SQLite install on Windows

1. Download the sqlite package from http://sqlite.org/download.html (you will need a file called sqlitedll-3_x_y.zip where x and y are numbers (they change, unfortunately). For reference I used sqlitedll-3_3_17.zip when I downloaded it. The download page is shown below:
2. When you have downloaded the file, unzip it and extract it to a directory called sqlite on your usb stick (you may need to create this directory first.) You should then copy the sqlite3.dll file to your ruby\bin directory.
3. Next use the gem command again to install the ruby-sqlite bindings so that ruby can use sqlite. The command is given below:
4. gem install sqlite3-ruby (choose option 2 from the menu)
5. Rails apps should be stored in their own directory – I tend to call it railsapps. Create this directory on your usb stick
6. To test that rails is working properly type the following commands:
   1. cd railsapps
   2. rails mytest --database=sqlite3
   3. cd mytest
   4. ruby script/server
7. Now start IE (ugh!?!?) or Firefox (yep!) and enter localhost:3000 into the URL bar, you should see the screen below:

MVC & Controllers

1. Using the instructions given above, create a new application called myapp, connected to a sqlite database, and cd into the directory. 2. Create a controller using ruby script/generate controller Say 3. cd into the app\controllers directory and open the say_controller.rb skeleton. 4. Add the hello class as shown below: 5. Create a new view template in the app\views\say directory, called hello.rhtml 6. Code is given below: 7. Test the above, what do you see? 8. Add a goodbye method to the say controller using the instructions above. 9. Create a goodbye view to accompany the goodbye method, but change the message to “see you later” 10. Modify the hello view to have a link to the goodbye view, example below 11. What does the h helper do? 12. Create a link from goodbye back to hello 13. Investigate the formatting options/helpers available to make the time display more manageable.