Updates

• added to_csv functionality (works with belongs_to, has_one and has_many relationships)
• added temporary table functionality
• added foreign key functionality

to_csv functionality

Example 1, exporting all fields

 class Book < ActiveRecord::Base ; end

 book = Book.find( 1 )
 book.to_csv

Example 2, only exporting certain fields

 class Book < ActiveRecord::Base ; end

 book = Book.find( 1 )
 book.to_csv( :only=>%W( title isbn )

Example 3, exporting a model including a belongs_to association

 class Book < ActiveRecord::Base
   belongs_to :author
 end

 book = Book.find( 1 )
 book.to_csv( :include=>:author )

This also works for a has_one relationship. The :include option can also be an array of has_one/belongs_to associations. This by default includes all fields on the belongs_to association.

Example 4, exporting a model including a has_many association

class Book < ActiveRecord::Base
  has_many :tags
end

book = Book.find( 1 )
book.to_csv( :include=>:tags )

This by default includes all fields on the has_many assocaition. This can also be an array of multiple has_many relationships. The array can be mixed with has_one/belongs_to associations array as well. IE: :include=>[ :author, :sales ]

Example 5, nesting associations

 class Book < ActiveRecord::Base
   belongs_to :author
   has_many :tags
 end

 book = Book.find( 1 )
 book.to_csv( :include=>{
                 :author => { :only=>%W( name ) },
                 :tags => { :only=>%W( tagname ) } )

Example 6, using Arrays returned by find

 class Book < ActiveRecord::Base
   belongs_to :author
   has_many :tags
 end

 books = Book.find( :all )
 books.to_csv( :include=>{
                 :author => { :only=>%W( name ) },
                 :tags => { :only=>%W( tagname ) } )

Temporary Table Support

Example 1, using defaults

 class Project < ActiveRecord::Base ; end

 Project.create_temporary_table

This creates a temporary table named ‘temp_projects’ and creates a constant name TempProject. The table structure is copied from the projects table.

Example 2, using :table_name and :model options

Project.create_temporary_table :table_name=>'my_projects', :model=>'MyProject'

This creates a temporary table named ‘my_projects’ and creates a constant named MyProject. The table structure is copied from the projects table.

Example 3, using :like

ActiveRecord::Base.create_temporary_table :like=>Project

This is the same as calling Project.create_temporary_table.

Example 4, using block form

Project.create_temporary_table do |t|
  # ...
end

Using the block form will automatically drop the temporary table when the block exits. t which is passed into the block is the temporary table class. In the above example t equals TempProject. The block form can be used with all of the available options.

Foreign Key Support

Enables support for enabling and disabling foreign keys for the underlying database connection for ActiveRecord. This can be used with or without block form. This also uses the connection attached to the model.

Example 1, without block form

Project.foreign_keys.disable
Project.foreign_keys.enable

If you use this form you have to manually re-enable the foreign keys.

Example 2, with block form

Project.foreign_keys.disable do
  # ...
end

Project.foreign_keys.enable do
  # ...
end

If you use the block form the foreign keys are automatically enabled or disabled when the block exits. This currently does not restore the state of foreign keys to the state before the block was entered.

Download It Now!

“ActiveRecord::Extensions 0.4.0”:http://rubyforge.org/frs/?group_id=2113

Check it out from SVN into your Rails project

svn co svn://rubyforge.org/var/svn/arext/tags/ar-extensions-0.4.0 vendor/plugins/