1.Presentation to Siltek Software Solutions (I) Pvt. Ltd.

2. Why does RoR interest us? Learn new concepts and terms. Look at new architecture. Find out what is good and what is dubious. May well come across RoR or a Rails-like framework in near future. May want to learn an object-oriented language relatively painlessly. RoR is easy to install, learn and use. You might want to try it out for yourself! 3. Creator of Ruby Creator of Ruby Yukihiro Matsumoto aka Matz Birthday: 24 February 1993 Originated in Japan and Rapidly Gaining Mindshare in US and Europe. 4. Presentation Agenda Brief overview of Ruby Rails Demonstration Description of Rails framework Questions and Answers 5. Why Ruby? Write more understandable code in less lines Free (Very open license) Extensible 6. What is Ruby? Dynamic, high level, interpreted, pure object-orientated language. Ruby is designed to make programmers happy Yukihiro Matsumoto aka Matz 7. What is Ruby? Ruby is a pure object-oriented programming language with a super clean syntax that makes programming elegant and fun. In Ruby, everything is an object Ruby is an interpreted scripting language, just like Perl, Python and PHP. Ruby successfully combines Smalltalk's conceptual elegance, Python's ease of use and learning and Perl's pragmatism. Ruby is a metaprogramming language. Metaprogramming is a means of writing software programs that write or manipulate other programs thereby making coding faster and more reliable. 8. Ruby is Truly Object-Oriented All classes derived from Object including Class (like Java) but there are no primitives (not like Java at all) Ruby uses single-inheritance Mixins give you the power of multiple inheritance without the headaches Modules allow addition of behaviors to a class Reflection is built in along with lots of other highly dynamic metadata features Things like = and + that you might think are operators are actually methods (like Smalltalk) 9. Dynamic Programming Duck Typing Based on signatures, not class inheritance Dynamic Dispatch A key concept of OOP: methods are actually messages that are sent to an object instance Dynamic Behavior Reflection Scope Reopening (Kind of like AOP) Eval Breakpoint debugger 10. What about Ruby on Rails? 11. Terms and Concepts MVC (Model-View-Controller) Duck Typing DRY (Dont Repeat Yourself) Convention Over Configuration Scaffolding Migrations Validations Associations Mailers 12. Directory Layout Rails applications have a common directory structure /app - the MVC core /controllers /helpers - provides extra functionality for views /models /views/nameofcontroller - templates for controller actions 13. Directory Layout /components - will be deprecated /config - database, route and environment configuration /db - database schema and migrations /lib - functions that dont map to MVC /log /public - static web resources (html, css, javascript etc.) /script - rails utilities /test - tests and fixtures /tmp /vendor - 3rd party plugins 14. Rails Directory Structure 15. MVC Architecture 16. The Obligatory Architecture Slide 17. Model View Controller Separate data (model) from user interface (view) Model data access and business logic independent of the view and controller View data presentation and user interaction read-only access to the model Controller handling events operating on model and view 18. Model Active Record Object Relational Mapping ActiveRecord Less Database glue Code Logging for Performance Checking 19. Model : Rules Table Names Plurals Attribute Names id for primary key in table table_id for foreign key in other table 20. View Action View multiple template types oldest and basic: erb (embedded ruby), similar to e.g. jsp remote javascript templates xml templates easy reuse of view elements file inclusion layouts, templates, partials multiple standard "helpers" common html element generators (e.g. form elements, paginators) easy AJAX integration 21. Controller : ActionController Method name matches view folder users_controller.rb works for /views/users/***.rhtml called actions all views methods will sit there Ability to CRUD Flash Redirect 22. Database Persistence OR mapping Active Record design pattern migrations incremental schema management multiple db adapters MySQL, PostgreSQL, SQLite, SQL Server, IBM DB2, Informix, Oracle 23. Duck Typing in Ruby Objects are dynamic, and their types are determined at runtime The type of a Ruby object is much less important than its capabilities If a Ruby object walks like a duck and talks like a duck, then it can be treated as a duck 24. Convention over Configuration fixed directory structure everything has its place source files, libs, plugins, database files, documentation etc file naming conventions e.g. camel case class name, underscore file name database naming conventions table names, primary and foreign keys standard configuration files e.g. database connections, environment setting definitions (development, production, test) 25. DRY - Dont Repeat Yourself reusing code e.g. view elements reusing data e.g. no need to declare table field names can be read from the database making each line of code work harder e.g. mini languages for specific domains object-relational mapping metaprogramming dynamically created methods 26. Rails Environment Modes Rails runs in different modes, depending on the parameters given to the server on startup. Each mode defaults to its own database schema Development (verbose logging and error messages) Test Production 27. Web Servers Lighttpd Mongrel WEBrick Apache 28. RoR Databases Mysql Oracle Postgre Sql SqlLite 29. Scaffolding Rails can generate all the basic CRUD operations for simple models via scaffolding. Scaffolding is temporary way to get applications wired quickly. ruby script/generate scaffold_resource bookmark url:string title:string 30. Migrations Rails uses migrations to version the database. Rails tries to minimize SQL at every opportunity Migrations are automatically created whenever you generate a new model Migration files are located in db/migrations The version number is stored in a table called schema_info 31. Running the Migration Rake is the general purpose build tool for rails, much like make, or ant. It has many functions, one of which is to control migrations. rake db:migrate Now the table has been created 32. Validations Rails has a number of validation helpers that can be added to the model. class Bookmark < ActiveRecord::Base validates_presence_of :url, :title end 33. Validations validates_presence_of validates_length_of validates_acceptance_of validates_confirmation_of validates_uniqueness_of validates_format_of validates_numericality_of validates_inclusion_in validates_exclusion_of validates_associated :relation 34. Associations Rails uses associations to build relationships between tables Associations are independent of database foreign key constraints 35. Types of Associations has_one belongs_to has_many has_and_belongs_to_many has_many :model1, :through => :model2 36. Mailers Action Mailer allows you to send emails from your application using a mailer model and views. So, in Rails, emails are used by creating models that inherit from ActionMailer::Base that live alongside other models in app/models. Those models have associated views that appear alongside controller views in app/views. 37. Rake Rubys Build System Familiar to Ant users Your build file is a written in Ruby Basic build script provided with Rails project 38. Recommended Rails reading Simply Rails 2.0 Sitepoint.com Great for beginners Agile Web Development with Rails PragProg.com A little bit more advanced 39. Resources Ruby on Rails: Talk (Google Group) http://groups.google.com/group/rubyonrails-talk Railscasts (free Ruby on Rails screencasts) http://railscasts.com Peep Code (paid Rails-related screencasts) http://peepcode.com Phusion Passenger (easy deployment module) http://www.modrails.com Agile Web Development (plugin central) http://agilewebdevelopment.com/ 40. Who uses Ruby on Rails? 41. References www.slideshare.net www.youtube.com www.google.com http://www.netbeans.org/kb/docs/ruby/rapid-ruby- weblog.html http://guides.rails.info/getting_started.html www.rubyonrails.org http://www.tutorialspoint.com/ruby-on-rails-2.1