filter form in Rails?

Question

I am a newbie to Rails. I have simply scaffolded a small model. The model has a field called category. Now I want to filter the entries on the index page by category.

<% form_for @domain do |f| %>
<p>
 Domain:
 <%= f.select(:Domain,%w{ LifeStyle Automobiles FoodAndBeverage Health IT Telecom EntertainmentAndCelebrity Education BankingInvestmentAndInsurance Travel Sports Parenting ConsumerElectronics RealtyAndLogistics CauseLed})%>


 <%= submit_tag "Filter" %>
</p>
<% end %>

<table border="1">
  <tr>
    <th>Domain</th>
    <th>Category</th>
    <th>Course detail</th>
    <th>Nameofblog</th>
    <th>Descriptionofblog</th>
    <th>Smename</th>
    <th>Smecommuntiy</th>
    <th>Smeifnotorkfac</th>
    <th>Noofmemb</th>
    <th>Discussionforumname</th>
    <th>Discussionforumdescription</th>
    <th>Qnasitesname</th>
    <th>Qnasitesnamedesc</th>
    <th>Newssitename</th>
    <th>Newssitedesc</th>
  </tr>

<% @media_universe_entries.each do |media_universe_entry| %>
  <tr>
    <td><%=h media_universe_entry.Domain %></td>
    <td><%=h media_universe_entry.Category %></td>
    <td><%=h media_universe_entry.CourseDetail %></td>
    <td><%=h media_universe_entry.NameOfBlog %></td>
    <td><%=h media_universe_entry.Descriptionofblog %></td>
    <td><%=h media_universe_entry.SMEname %></td>
    <td><%=h media_universe_entry.SMECommuntiy %></td>
    <td><%=h media_universe_entry.SMEIfnotOrkFac %></td>
    <td><%=h media_universe_entry.NoOfMemb %></td>
    <td><%=h media_universe_entry.discussionforumname %></td>
    <td><%=h media_universe_entry.discussionforumdescription %></td>
    <td><%=h media_universe_entry.QNASitesname %></td>
    <td><%=h media_universe_entry.QNASitesnameDesc %></td>
    <td><%=h media_universe_entry.NewsSiteName %></td>
    <td><%=h media_universe_entry.NewsSiteDesc %></td>
    <td><%= link_to 'Show', media_universe_entry %></td>
    <td><%= link_to 'Edit', edit_media_universe_entry_path(media_universe_entry) %></td>
    <td><%= link_to 'Destroy', media_universe_entry, :confirm => 'Are you sure?', :method => :delete %></td>
  </tr>
<% end %>
</table>

<br />

<%= link_to 'New media_universe_entry', new_media_universe_entry_path %>

As you can see I am trying to make a domain wise filetring. How do i do this?

Answer 1

Hi. You should post the controller method also, to better understand the model.

Anyway, assuming that the model Something has a string "category" column, you should not hardcode the values for the select, unless these values are fixed, in which case you might consider not using a string column.

Here's a fast-typed example:

# something_controller.rb
  def index
    @categories = Something.find_by_sql("SELECT category FROM somethings GROUP BY category").map &:category
    @somethings = params[:category].blank? ? Something.all : Something.find_all_by_category(params[:category])
  end

this is the view:

<% form_tag(:action => :index) do %>
  <%= select_tag "category", options_for_select(@categories) %>
  <%= submit_tag "Filter" %>
<% end %>

<table>
  <tr>
    <th>foo</th>
    ...
  </tr>
  <% somethings.each do |something| %>
    <tr>
      <td><%= something.foo %></td>
      ...
    </tr>
  <% end %>
</table>

Update:

While the above code works, it was really too fastcoded, and suggests bad practise.

Here's a better way:

# app/models/Something.rb
def self.all_categories
  find_by_sql("SELECT category FROM somethings GROUP BY category").map(&:category).select {|x| x}
end

def self.select(category)
  if category
    find_all_by_category(category)
  else
    find :all
  end
end

#app/controllers/something_controller.rb
def index
  @categories = Something.all_categories
  @somethings = Something.select(params[:category])
end