web application development and advanced web app development cs1019/cs2012 introduction bruce...
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Bruce Scharlau, University of Aberdeen, 2012
Web Application Development and
Advanced Web App DevelopmentCS1019/CS2012
Introduction
Bruce Scharlau, University of Aberdeen, 2012
Why are you here?
Write answer down on piece of paper and discuss it with the person next to you
Bruce Scharlau, University of Aberdeen, 2012
This course sets up your programming experience
• Programming language• Programming concepts• Programming tools • Bootstrap you so that you know how to
deal with unforeseen events
Bruce Scharlau, University of Aberdeen, 2012
The two course organisers
• Nigel Beacham for Web App Development• Bruce Scharlau for Advanced Web App Dev
Bruce Scharlau, University of Aberdeen, 2012
Take control of your own learning
• Lectures once a week• Practical sessions once a week• Coursework at regular times• Book list• Web sites
Also course guides to help you - so read them first
Bruce Scharlau, University of Aberdeen, 2012
This week’s practical puts software on your laptop
• Bring your laptop to this week’s practicals• There are often little problems to resolve,
so install software ahead of time before proper practicals start next week.
• Come and see how it’s done if you intend to install it on desktop at home
• See what problems you may need to watch for when you do it on your own
Bruce Scharlau, University of Aberdeen, 2012
Use a virtual Linux machine
We STRONGLY recommend you install a virtual Linux machine on your laptop if you’re on a Windows laptop
Using a Linux box to learn Ruby programming will make your life easier and has proven to be a better practice by previous students
Bruce Scharlau, University of Aberdeen, 2012
Programming needs practice• You are expected to spend at least an hour a
day working through examples to learn to program
• You need time to become familiar with programming so that you understand how the examples work
Bruce Scharlau, University of Aberdeen, 2012
Programming needs practice
You are unlikely to pass the course, if you do not spend the time practicing examples
Bruce Scharlau, University of Aberdeen, 2012
There is no substitute for time at the keyboard
• You need to practice so that you assimilate the materials
• This means you should do an hour of programming exercises each day –over and above classwork
Time spent practicing now pays off with better course marks
Bruce Scharlau, University of Aberdeen, 2012
Bookmark and use the web sites
MyAberdeen will have most everything you need – Recorded lectures– Quizes
You can also find most materials at:
http://homepages.abdn.ac.uk/b.scharlau/pages/teaching/CS5550/practicals/
Bruce Scharlau, University of Aberdeen, 2012
Check Q & A in forums at MyAberdeen
• Put questions in discussion forum on webCT and we and your classmates can answer them for you.
• Everyone can see the answer.
Bruce Scharlau, University of Aberdeen, 2012
Use these books on the course • Hunt, Andy.
Pragmatic Thinking and Learning: Refactor Your Wetware Pragmatic Bookshelf, 2008. For your learning
• Ruby, Sam. Agile Web Development with Rails (4th edition), 2011. Pragmatic Bookshelf. This is the latest edition and covers Rails 3. For Rails
• Wynne, Matt and Hellesoy, Aslak. The Cucumber Book: Behaviour-Driven Development for Testers and Developers. January 2012 Pragmatic Bookshelf. For testing Ruby and Rails
Links on website and MyAberdeen
Bruce Scharlau, University of Aberdeen, 2012
Use this software on the course
Application/Library and version numbers
• Ruby – Ruby 1.9.x• RubyGems – package installer• plus assorted gems as detailed elsewhere
• Rails – Rails 3.0.x • Sqlite3 for the database• Git for version source control
Bruce Scharlau, University of Aberdeen, 2012
You also need a text editor• Text editor provides clean place to write
programs. • Komodo Edit is free on all platforms
– http://www.activestate.com/komodo_edit/
MS Word is NOT a text editor
Bruce Scharlau, University of Aberdeen, 2012
text editor is needed because …
• It shows all of the characters in a file• A word processed file has many other
characters in the file than are shown on the screen
• Your program needs to only run what you give it
Bruce Scharlau, University of Aberdeen, 2012
Assessment work is important
• Assessment work accounts for 50%• A ruby one for 25% and a rails one for 25%• Exam counts for 50% of mark
• Assessment work accounts for 100%• 20 weekly assignments, 30% on team
assignment & 50% individual assignment
WAD
AWAD
Bruce Scharlau, University of Aberdeen, 2012
Coursework is important
In order to pass the course you MUST submit
assessments
You cannot rely upon only passing the exam
Bruce Scharlau, University of Aberdeen, 2012
Why study programming?• Because it's a combination of intelligent and
creative work.• The pride of seeing your work used by other
people.• Get paid to have fun.• Be able to program anywhere, anytime, with
my choice of platform, programming language, and architecture.
• http://www.ddj.com/architect/196603871
Bruce Scharlau, University of Aberdeen, 2012
Agile development process
• We’ll focus on agile development • http://agilemanifesto.org/ • Our concern is: incremental and iterative
development • Do small steps often in other words
Bruce Scharlau, University of Aberdeen, 2012
Use software tests to support your code
• We’ll also focus on writing tests for our code to check it does what it should
• This provides a safety net so we know when we broke the app with our new code
Bruce Scharlau, University of Aberdeen, 2012
Let us know if there are problems
• We rely upon YOU to give us feedback• Let us know what’s working well• Let us know what’s not working• Let us know where you’re having problems
understanding something
If you tell, us then we can do something.If you don’t tell us, then we don’t know.
Bruce Scharlau, University of Aberdeen, 2012
What is programming?
• Write it down on page…
• Share it with person next to you…
Bruce Scharlau, University of Aberdeen, 2012
‘what is programming?’: answer
• Telling the computer what to do• Warning:
– (a) it follows your instructions, so if you get it wrong…
– (b) if you leave out an instruction, then …
Bruce Scharlau, University of Aberdeen, 2012
We write programs to make instructions easier to maintain
• Use programming language to make it easier for us
• Computer only understand binary• 01100011 01101111 01101101 01110000 01110101 01110100
01100101 01110010 01110011 00100000 01101111 01101110 01101100 01111001 00100000 01110101 01101110 01100100 01100101 01110010 01110011 01110100 01100001 01101110 01100100 00100000 01100010 01101001 01101110 01100001 01110010 01111001
Bruce Scharlau, University of Aberdeen, 2012
There are a lot of programming languages out there
• Compiled languages– C, C++, Lisp, Visual Basic, others
• Interpreted languages– Shell scripting such as bash, csh, and others– Interpreted languages PHP, JavaScript– Intermediate interpreted languages
• Python, Ruby• Java and C# are first compiled to virtual machine
code and then interpreted
Bruce Scharlau, University of Aberdeen, 2012
We’ll use Ruby
• Public since 1995, same as Java• Hit massive growth with public release of
Rails in Feb 2005• Growing impact in programming world
• http://en.wikipedia.org/wiki/Ruby_(programming_language• http://www.ruby-lang.org/en/
• http://en.wikipedia.org/wiki/Ruby_on_Rails • http://rubyonrails.org/
http://en.wikipedia.org/wiki/File:Ruby_logo.svg
Bruce Scharlau, University of Aberdeen, 2012
Ruby offers lots of advantages
• Easy to read• Object orientated, so easy to use
– Objects, classes, methods• Less frustrating to use, so you make fewer
errors• Runs on lots of platforms, and is free• Plenty of ‘extra’ libraries you can add for
other features to cover math, graphics, etc
Bruce Scharlau, University of Aberdeen, 2012
Time for a demo
• We need the following – Text editor to write program– Command line to run/execute the program
Bruce Scharlau, University of Aberdeen, 2012
We used strings and integers
• Strings are between quotations marks• Integers are numbers• If we multiply strings then they are printed
out that many times• Puts means ‘print string and add a new
line’
Bruce Scharlau, University of Aberdeen, 2012
Have a strategy to handle errors
• Read the error message- there is often a clue there
• Think through the steps you put in the code – sometimes you put the steps out of order
• Google the error message – others will have probably also had the problem
Bruce Scharlau, University of Aberdeen, 2012
Variables are assigned values
a = 23
name = ‘fred’
b = ‘twenty’
a = b
• Variables are like labels on boxes, and some boxes have more than one label
• So what’s the value of ‘a’ at the end?
Bruce Scharlau, University of Aberdeen, 2012
Assignment uses the = symbol
Always assign the variable on the left with the value on the right
a = 23
a = a+23
name = ‘fred ’ + a.to_s
What’s the value of ‘a’?
Bruce Scharlau, University of Aberdeen, 2012
Use gets for keyboard input
puts ‘what\’s your name?’
name = gets
puts ‘Hello ‘ + name
• Why is there a \ (backslash)?• Why is there a space after Hello?
Bruce Scharlau, University of Aberdeen, 2012
Also be developing web apps
• You’ll be putting web apps online before the end of term
• Start with basic Ruby first so that you understand what’s happening in Rails code
Bruce Scharlau, University of Aberdeen, 2012
Practice
The DIT labs have all that you need to run Ruby so you can run through some of the exercises that are in any of the books
Read first few chapters before the practical
Also start reading the course guide