The document discusses the benefits of using Ruby and Rails for web development compared to other technologies like Java. It highlights how Ruby and Rails allow for more concise and readable code through features like Haml for HTML, Sass for CSS, and conventions like MVC frameworks. Examples are given of how common tasks like creating a blog with entries can be done in fewer lines of code in Ruby on Rails compared to other languages.

2. Why code in Ruby / Rails?

4. I like Java

5. + Sign me up!

6. But I like Ruby better.

7. Brevity.

8. import java.util.Map; import java.util.HashMap; ... Map<Integer, String> hash = new HashMap<Integer, String>(); hash.put(1, &quot;one&quot; ); hash.put(2, &quot;two&quot; ); hash.put(3, &quot;three&quot; );

9. hash = { 1 => &quot; one &quot; , 2 => &quot; two &quot; , 3 => &quot; three &quot; }

10. Rails is (mostly) concise.

11. $ rails blog $ cd blog $ ruby script/generate scaffold entry subject:string content:text $ rake db:migrate $ ruby script/server

12. class Entry < ActiveRecord :: Base end

13. class EntriesController < ApplicationController # GET /entries # GET /entries.xml def index @entries = Entry .all respond_to do | format | format.html # index.html.erb format.xml { render :xml => @entries } end end ...

14. < h1 > Listing entries </ h1 > < table > < tr > < th > Subject </ th > < th > Content </ th > </ tr > <% @entries .each do | entry | %> < tr > < td > <%= h entry.subject %> </ td > < td > <%= h entry.content %> </ td > < td > <%= link_to ' Show ', entry %> </ td > < td > <%= link_to ' Edit ', edit_entry_path(entry) %> </ td > < td > <%= link_to ' Destroy ', entry, :confirm => ' Are you sure? ' , :method => :delete %> </ td > </ tr > <% end %> </ table > < br /> <%= link_to ' New entry ', new_entry_path %>

15. HTML in ERb screws everything up.

16. import java.util.Map; import java.util.HashMap; ... Map<Integer, String> hash = new HashMap<Integer, String>(); hash.put( 1, &quot;one&quot; ); hash.put( 2, &quot;two&quot; ); hash.put( 3, &quot;three&quot; ); Ruby does away with redundant code

17. What if we could do it here too? < h1 > Listing entries </h1> < table > < tr > < th > Subject </th> < th > Content </th> </tr> <% @entries.each do |entry| %> < tr > < td ><% =h entry.subject %></td> < td ><% =h entry.content %></td> < td ><% = link_to 'Show', entry %></td> < td ><% = link_to 'Edit', edit_entry_path(entry) %></td> < td ><% = link_to 'Destroy', entry, :confirm => 'Are you sure?', :method => :delete %></td> </tr> <% end %> </table> < br /> <% = link_to 'New entry', new_entry_path %>

18. Enter Haml

19. % h1 Listing entries Declaring Elements

20. % table % tr % th Subject % th Content Nesting Elements

21. %table %tr %th Subject %th Content - @entries .each do | entry | %tr % td &= entry.subject % td &= entry.content % td = link_to ' Show ' , entry % td = link_to ' Edit ' , edit_entry_path(entry) Ruby Code

22. % p { :style => &quot; color: green &quot; }= notice Attributes

23. % div { :class => &quot; error &quot; , :id => &quot; some_id &quot; } Some Text can be shortened to . class # some_id Some Text divs, classes, and id

24. Why stop at ERb?

25. Sass does with CSS what Haml does with HTML .

26. pre background-color : #eee padding : 10px font-size : 11px No braces! No semicolons!

27. # errorExplanation width: 400px border: 2px solid red padding: 7px padding-bottom: 12px margin-bottom: 20px background-color: #f0f0f0 h2 text-align: left font-weight: bold ... Nested Selectors!

28. $fore: # 333 $bg: # fff body background-color : $bg color : $fore Constants!

29. @mixin rounded($radius: 10px) border-radius: $radius -moz-border-radius: $radius -webkit-border-radius: $radius . fieldWithErrors @include rounded(5px) ... # errorExplanation @include rounded ... Method-like structures!

30. Short Demo

31. Thank you for listening! my site: http://www.bryanbibat.net