added custom conditions - see user filter example

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    will_filter (3.1.3)
+    will_filter (3.1.4)
       coffee-script
       kaminari
       rails (>= 3.1.0)

app/models/will_filter/filter.rb

@@ -483,6 +483,7 @@ def sql_conditions
           all_sql_conditions = [""]
           0.upto(size - 1) do |index|
             condition = condition_at(index)
+            next if custom_condition?(condition)
 
             sql_condition = condition.container.sql_condition
 
@@ -685,14 +686,62 @@ def joins
         "INNER JOIN #{join_table_name} ON #{join_table_name}.id = #{table_name}.#{join_on_field}"
       end
     end
-
+
+    # overload this method to indicate which conditions are custom
+    def custom_conditions
+      []
+    end
+
+    # overload this method to evaluate a custom condition on an object
+    def custom_condition_met?(condition, object)
+      false
+    end
+
+    def custom_condition?(condition)
+      custom_conditions.include?(condition.key)
+    end
+
+    def custom_conditions?
+      return if custom_conditions.empty?
+      conditions.each do |condition|
+        return true if custom_condition?(condition)
+      end
+    end
+
+    def process_custom_conditions(objects)
+      filtered = []
+      objects.each do |obj|
+        condition_flags = []
+
+        0.upto(size - 1) do |index|
+          condition = condition_at(index)
+          next unless custom_condition?(condition)
+          condition_flags << custom_condition_met?(condition, obj)
+        end
+
+        if condition_flags.size > 0
+          next if match.to_s == "all" and condition_flags.include?(false)
+          next unless condition_flags.include?(true)        
+        end 
+
+        filtered << obj 
+      end
+      filtered
+    end
+
     def results
       @results ||= begin
         handle_empty_filter! 
         recs = model_class.where(sql_conditions).order(order_clause)
         inner_joins.each do |inner_join|
           recs = recs.joins(association_name(inner_join))
         end
+
+        if custom_conditions?
+          recs = process_custom_conditions(recs.all)
+          recs = Kaminari.paginate_array(recs)
+        end  
+
         recs = recs.page(page).per(per_page)
         recs.wf_filter = self
         recs

test/dummy/app/models/user_filter.rb

@@ -4,14 +4,21 @@ def definition
     defs = super  
     defs[:sex][:is] = :list
     defs[:sex][:is_not] = :list
+    defs[:custom_condition] = {
+      :is => :list
+    }
     defs
   end
 
-  def value_options_for(criteria_key)
-    if criteria_key == :sex
+  def value_options_for(condition_key)
+    if condition_key == :sex
       return ["male", "female"]
     end
 
+    if condition_key == :custom_condition
+      return [["Third letter in the First Name is an 'a'", 'a'], ['Id is divisible by 3', '3']]
+    end
+
     return []
   end
 
@@ -54,4 +61,22 @@ def default_filter_if_empty
     "male_only"
   end
 
+  def custom_conditions
+    [:custom_condition]
+  end
+
+  def custom_condition_met?(condition, object)
+    if condition.key == :custom_condition
+      if condition.operator == :is
+        if (condition.container.value == 'a')
+          return (object.first_name[2..2] == 'a')
+        elsif (condition.container.value == '3')  
+          return (object.id % 3 == 0)
+        end
+      end 
+    end
+
+    return false
+  end
+
 end