#12 | Added 'where' method to base

lib/scrapify.rb

@@ -6,5 +6,6 @@
 require 'net/http'
 require 'scrapify/base'
 require 'scrapify/scraper'
+require 'scrapify/exceptions'
 require 'json'
 require 'jsonify'

lib/scrapify/base.rb

@@ -106,6 +106,15 @@ def define_finders
           attributes = Hash[attribute_names.map {|attribute| [attribute, send("#{attribute}_values")[index]]}]
           self.new(attributes)
         end
+
+        define_singleton_method :where do |conditions = {}|
+          raise Scrapify::AttributeDoesNotExist.new(conditions.keys - attribute_names) unless conditions.keys.all?{|key| attribute_names.include?(key) }
+          indices = conditions.collect do |attribute, value|
+            send("#{attribute}_values").each_with_index.find_all{|attr_val, index| attr_val == value}.collect(&:last)
+          end
+          common_indices = indices.reduce {|a, b| a & b}
+          common_indices.collect{|index| find_by_index(index)}
+        end
       end
 
       def define_count(key_attribute)

lib/scrapify/exceptions.rb

@@ -0,0 +1,3 @@
+module Scrapify
+  class AttributeDoesNotExist < StandardError; end
+end

spec/shared/finder.rb

@@ -0,0 +1,10 @@
+shared_examples_for '#finder' do |klass_or_object, conditions|
+  it 'should fetch objects based on conditions' do
+    pizza = klass_or_object.where(conditions).first
+    pizza.name.should == 'chicken golden delight'
+    pizza.image_url.should == 'golden.jpg'
+    pizza.price.should == '4.56'
+    pizza.ingredients.should be_empty
+    pizza.ingredient_urls.should == ['chicken.html', 'delight.html']
+  end
+end

spec/shared/scrapify.rb

@@ -175,4 +175,20 @@
       ].to_json
     end
   end
+
+  it_behaves_like '#finder', klass_or_object, :name => 'chicken golden delight'
+  it_behaves_like '#finder', klass_or_object, :image_url => 'golden.jpg'
+  it_behaves_like '#finder', klass_or_object, :price => '4.56'
+  it_behaves_like '#finder', klass_or_object, :ingredient_urls => ['chicken.html', 'delight.html']
+  it_behaves_like '#finder', klass_or_object, :name => 'chicken golden delight', :image_url => 'golden.jpg', :price => '4.56', :ingredient_urls => ['chicken.html', 'delight.html']
+
+  it 'should return empty array if object is not found' do
+    klass_or_object.where(:name => 'does not exist').should be_empty
+  end
+
+  it 'should throw exception if attribute is not defined' do
+    lambda {
+      klass_or_object.where(:some_attribute => 'chicken golden delight')
+    }.should raise_error(Scrapify::AttributeDoesNotExist)
+  end
 end