Initial work on sort_link. Mostly ported from MetaSearch, changes coming soon

lib/ransack/helpers/form_builder.rb

@@ -73,6 +73,10 @@ module Ransack
         search_fields(:s, args, block)
       end
 
+      def sort_link(attribute, *args)
+        @template.sort_link @object, attribute, *args
+      end
+
       def condition_fields(*args, &block)
         search_fields(:c, args, block)
       end

lib/ransack/helpers/form_helper.rb

@@ -1,6 +1,7 @@
 module Ransack
   module Helpers
     module FormHelper
+
       def search_form_for(record, options = {}, &proc)
         if record.is_a?(Ransack::Search)
           search = record
@@ -23,6 +24,52 @@ module Ransack
         form_for(record, options, &proc)
       end
 
+      def sort_link(search, attribute, *args)
+        raise TypeError, "First argument must be a Ransack::Search!" unless Search === search
+
+        search_params = params[:q] || {}.with_indifferent_access
+
+        attr_name = attribute.to_s
+
+        name = (args.size > 0 && !args.first.is_a?(Hash)) ? args.shift.to_s : Translate.attribute(attr_name, :context => search.context)
+
+        if existing_sort = search.sorts.detect {|s| s.name == attr_name}
+          prev_attr, prev_dir = existing_sort.name, existing_sort.dir
+        end
+
+        options = args.first.is_a?(Hash) ? args.shift.dup : {}
+        default_order = options.delete :default_order
+        current_dir = prev_attr == attr_name ? prev_dir : nil
+
+        if current_dir
+          new_dir = current_dir == 'desc' ? 'asc' : 'desc'
+        else
+          new_dir = default_order || 'asc'
+        end
+
+        html_options = args.first.is_a?(Hash) ? args.shift.dup : {}
+        css = ['sort_link', current_dir].compact.join(' ')
+        html_options[:class] = [css, html_options[:class]].compact.join(' ')
+        options.merge!(
+          :q => search_params.merge(:s => "#{attr_name} #{new_dir}")
+        )
+        link_to [ERB::Util.h(name), order_indicator_for(current_dir)].compact.join(' ').html_safe,
+                url_for(options),
+                html_options
+      end
+
+      private
+
+      def order_indicator_for(order)
+        if order == 'asc'
+          '▲'
+        elsif order == 'desc'
+          '▼'
+        else
+          nil
+        end
+      end
+
     end
   end
 end

lib/ransack/search.rb

@@ -49,8 +49,10 @@ module Ransack
           sort = Nodes::Sort.new(@context).build(attrs)
           self.sorts << sort
         end
-      else
+      when String
         self.sorts = [args]
+      else
+        raise ArgumentError, "Invalid argument (#{args.class}) supplied to sorts="
       end
     end
     alias :s= :sorts=

lib/ransack/translate.rb

@@ -12,7 +12,7 @@ module Ransack
 
     def self.attribute(key, options = {})
       unless context = options.delete(:context)
-        raise ArgumentError, "A context is required to translate associations"
+        raise ArgumentError, "A context is required to translate attributes"
       end
 
       original_name = key.to_s

spec/ransack/helpers/form_builder_spec.rb

@@ -47,6 +47,14 @@ module Ransack
 
       end
 
+      describe '#sort_link' do
+        subject { @f.sort_link :name, :controller => 'people' }
+
+        it { should match /people\?q%5Bs%5D=name\+asc/}
+        it { should match /sort_link/}
+        it { should match /Full Name<\/a>/}
+      end
+
       describe '#submit' do
 
         it 'localizes :search when no default value given' do

spec/ransack/helpers/form_helper_spec.rb

@@ -0,0 +1,38 @@
+require 'spec_helper'
+
+module Ransack
+  module Helpers
+    describe FormHelper do
+
+      router = ActionDispatch::Routing::RouteSet.new
+      router.draw do
+        resources :people
+        match ':controller(/:action(/:id(.:format)))'
+      end
+
+      include router.url_helpers
+
+      # FIXME: figure out a cleaner way to get this behavior
+      before do
+        @controller = ActionView::TestCase::TestController.new
+        @controller.instance_variable_set(:@_routes, router)
+        @controller.class_eval do
+          include router.url_helpers
+        end
+
+        @controller.view_context_class.class_eval do
+          include router.url_helpers
+        end
+      end
+
+      describe '#sort_link' do
+        subject { @controller.view_context.sort_link(Person.search(:sorts => ['name desc']), :name, :controller => 'people') }
+
+        it { should match /people\?q%5Bs%5D=name\+asc/}
+        it { should match /sort_link desc/}
+        it { should match /Full Name ▼/}
+      end
+
+    end
+  end
+end