newbie question, "show items in selected city and category"

rubyonrails-talk
1

Hi, rails newbie needs help :slight_smile:

I have classified ads (cads) related with cities and categories:

class Cad < ActiveRecord::Base      has_and_belongs_to_many :categories      has_and_belongs_to_many :cities end

class Category < ActiveRecord::Base     has_and_belongs_to_many :cads end

class City < ActiveRecord::Base     has_and_belongs_to_many :cads end

I assume that user can act such way: first, from cities listing, which is produced by 'list' method in cities_controller, the user chooses city ( clicks on 'show' link).

cities_controller#show contains the following: def show     @city = City.find(params[:id])     @cads = @city.cads     @categories_of_cads_in_city = @cads.map {|cad| cad.categories}.flatten.uniq end

So, the user sees classified ads and categories of these ads:

cities/show.rhtml: [...] <% @cads.each do |cad| %> <%=link_to cad.title,     :controller => "cads",     :action => "show",     :id => cad.id %>

<% @categories_of_cads_in_city.each do |category| %> <%= link_to category.name,     :controller => "categories",     :action => "show",     :id => category.id %> [...]

The next thing user may want to do - see classified ads in some category of chosen city (assume in "Health" category) , so he clicks on link "Health". So i must find ads which are associated with chosen city and category "Health". How can i do achieve this ?? Thanks

2

ogurec wrote:

class Cad < ActiveRecord::Base      has_and_belongs_to_many :categories      has_and_belongs_to_many :cities end

class Category < ActiveRecord::Base     has_and_belongs_to_many :cads end

class City < ActiveRecord::Base     has_and_belongs_to_many :cads end

So i must find ads which are associated with chosen city and category "Health". How can i do achieve this ??

This is untested, and there may be an easier way, but this should work:

class Cad   def self.with_category_and_city(category, city)     with_scope :find => {:conditions => ["categories.id = ? AND cities.id = ?", category.id, city.id], :include => [:categories, :cities]} do       yield     end   end

  def self.find_by_category_and_city(category, city, *args)     with_category_and_city(category, city) { find(*args) }   end end

Set up like this, the Cad.find_by_category_and_city method will take standard ActiveRecord::Base.find options.

Example:   Cad.find_by_category_and_city(@category, @city, :first)   Cad.find_by_category_and_city(@category, @city, :all, :order => "cads.name")

Dan Manges

3

Many thanks Dan, i've added method 'category' into 'cities_controller' and its works!

I understand how @category gets its value regarding passed id, but how can i get the value of @city that was previously set in cities_controller#show ?

cities_controller#category @city = City.find(1) @category = Category.find(params[:id]) @cads = Cad.find_by_category_and_city(@category, @city, :all)

4

ogurec wrote:

Many thanks Dan, i've added method 'category' into 'cities_controller' and its works!

I understand how @category gets its value regarding passed id, but how can i get the value of @city that was previously set in cities_controller#show ?

cities_controller#category @city = City.find(1) @category = Category.find(params[:id]) @cads = Cad.find_by_category_and_city(@category, @city, :all)

I would pass both the ID for the city and the ID for category to your 'category' action.

Example, in the /cities/show view: <% for category in @categories %>   <%= link_to h(category.name), :action => 'category', :id => @city, :category => category %> <% end %>

The with the default routes the URL will be like: /cities/category/1?category=3 And then in the controller for that action: @city = City.find(params[:id]) @category = Category.find(params[:category])

Dan Manges

5

Thanks a lot!