negate search conditions

Gemfile

@@ -2,6 +2,8 @@ source 'http://rubygems.org'
 
 gem 'rails', '3.0.0.beta2'
 
+gem 'arel', :git => 'http://github.com/ernie/arel.git'
+
 gem 'sqlite3-ruby', :require => 'sqlite3'
 
 group :test do

app/models/item.rb

@@ -23,6 +23,8 @@ class Item < ActiveRecord::Base
         in_phrase = !in_phrase
       elsif c == ':' && !in_phrase
         query_conditions.last.to_property!
+      elsif c == '-' && !in_phrase && query_conditions.last.empty?
+        query_conditions.last.negate!
       else
         query_conditions.last << c
       end
@@ -35,26 +37,34 @@ class Item < ActiveRecord::Base
   private
   
   class Condition < String
-    attr_reader :property
-    
     def to_property!
       @property = self.clone
       self.replace ''
     end
     
+    def negate!
+      @negative = true
+    end
+    
     def narrow(scope)
+      items = Table(:objects)
       if @property == 'species'
         species = Species.find_by_name(self)
         # TODO: add a many-to-many table to handle this relationship
-        scope.where('species_support_ids = ? OR species_support_ids LIKE ? OR species_support_ids LIKE ? OR species_support_ids LIKE ?',
+        condition = items[:species_support_ids].matches_any(
           species.id,
           "#{species.id},%",
           "%,#{species.id},%",
           "%,#{species.id}"
         )
       else
-        scope.where('name LIKE :matcher OR description LIKE :matcher', :matcher => "%#{self}%")
+        matcher = "%#{self}%"
+        condition = items[:name].matches(matcher).or(
+          items[:description].matches(matcher)
+        )
       end
+      condition = condition.not if @negative
+      scope.where(condition)
     end
     
     def inspect

spec/models/item_spec.rb

@@ -1,6 +1,7 @@
 require 'spec_helper'
 
 describe Item do
+  context "an item" do
     specify "should accept string or array for species_support_ids" do
       items = [
         Factory.build(:item, :species_support_ids => '1,2,3'),
@@ -8,8 +9,10 @@ describe Item do
       ]
       items.each { |i| i.species_support_ids.should == [1,2,3] }
     end
+  end
   
-  specify "class should search name for word" do
+  context "class" do
+    specify "should search name for word" do
       query_should 'blue',
         :return => [
           'A Hat That is Blue',
@@ -23,7 +26,7 @@ describe Item do
         ]
     end
     
-  specify "class should search name for phrase" do
+    specify "should search name for phrase" do
       query_should '"one two"',
         :return => [
           'Zero one two three',
@@ -38,7 +41,7 @@ describe Item do
         ]
     end
     
-  specify "class should search name for multiple words" do
+    specify "should search name for multiple words" do
       query_should 'one two',
         :return => [
           'Zero one two three',
@@ -53,7 +56,7 @@ describe Item do
         ]
     end
     
-  specify "class should search name for words and phrases" do
+    specify "should search name for words and phrases" do
       query_should 'zero "one two" three',
         :return => [
           'zero one two three',
@@ -69,7 +72,7 @@ describe Item do
         ]
     end
     
-  specify "class should search name and description" do
+    specify "should search name and description" do
       query_should 'zero "one two"',
         :return => [
           'zero one two',
@@ -84,7 +87,7 @@ describe Item do
         ]
     end
     
-  specify "class should search by species" do
+    specify "should search by species" do
       [[2],[1,2,3],[2,3],[3],[1,3]].each do |ids|
         Factory.create :item, :species_support_ids => ids
       end
@@ -93,7 +96,7 @@ describe Item do
       Item.search('species:blumaroo').count.should == 4
     end
     
-  specify "class should search by species and words" do
+    specify "should search by species and words" do
       Factory.create :item, :name => 'Blue Hat', :species_support_ids => [1]
       Factory.create :item, :name => 'Very Blue Hat', :species_support_ids => [1,2]
       Factory.create :item, :name => 'Red Hat', :species_support_ids => [2]
@@ -102,4 +105,47 @@ describe Item do
       Item.search('red species:acara').count.should == 0
       Item.search('red species:aisha').count.should == 1
     end
+    
+    specify "should be able to negate word in search" do
+      query_should 'hat -blue',
+        :return => [
+          'Green Hat',
+          'Red Hat',
+          'Blu E Hat',
+          ['Yellow Hat', 'This hat is not green!']
+        ],
+        :not_return => [
+          'Blue Hat',
+          'Green Shirt',
+          'Blue Shirt',
+          ['Orange Hat', 'This hat is not blue!'],
+          ['Blue Pants', 'This is not a hat!']
+        ]
+    end
+    
+    specify "should be able to negate species in search" do
+      Factory.create :item, :name => 'Blue Hat', :species_support_ids => [1]
+      Factory.create :item, :name => 'Very Blue Hat', :species_support_ids => [1,2]
+      Factory.create :item, :name => 'Red Hat', :species_support_ids => [1,2]
+      Factory.create :item, :name => 'Green Hat', :species_support_ids => [3]
+      Factory.create :item, :name => 'Red Shirt', :species_support_ids => [3]
+      Item.search('hat -species:acara').count.should == 1
+      Item.search('hat -species:aisha').count.should == 2
+      Item.search('hat -species:acara -species:aisha').count.should == 1
+    end
+    
+    specify "should be able to negate phrase in search" do
+      query_should 'zero -"one two"',
+        :return => [
+          'Zero two one',
+          ['Two one', 'Zero'],
+          'One three two zero'
+        ],
+        :not_return => [
+          'Zero one two',
+          ['Zero', 'one two three'],
+          ['One two four', 'Zero one']
+        ]
+    end
+  end
 end