More filtering cleanup

app/filters/base_filter.rb

@@ -5,6 +5,10 @@
 # BaseFilter is more like an abstract parent class, but it also serves
 # as a NullObject version of the filter grouping, if you want one
 class BaseFilter
+  # This constant should be overriden if you need the ContributionController to
+  # accept additional parameters for this filter to work
+  ALLOWED_PARAMS = {}
+
   # This method should be overridden to return a hash with the following keys:
   # * :name => a short string that the user will see that describes what type of filters these are
   # * :filters => the output a call to FilterOptionBlueprint.render_as_hash that represent each filter option to check or uncheck

app/filters/category_filter.rb

@@ -1,4 +1,7 @@
 class CategoryFilter < BaseFilter
+  PARAM_NAME = 'Category'
+  ALLOWED_PARAMS = {PARAM_NAME => {}}
+
   def self.filter_grouping
     {
       name: "Categories",
@@ -8,9 +11,9 @@ def self.filter_grouping
   end
 
   def filter(scope)
-    return super unless parameters
+    return super if parameters[PARAM_NAME].blank?
     scope.tagged_with(
-      Category.roots.where(id: parameters.keys).pluck('name'),
+      Category.roots.where(id: parameters[PARAM_NAME].keys).pluck('name'),
       any: true
     )
   end

app/filters/contact_method_filter.rb

@@ -1,4 +1,7 @@
 class ContactMethodFilter < BaseFilter
+  PARAM_NAME = 'ContactMethod'
+  ALLOWED_PARAMS = {PARAM_NAME => {}}
+
   def self.filter_grouping
     {
       name: 'Contact Methods',
@@ -7,7 +10,7 @@ def self.filter_grouping
   end
 
   def filter(scope)
-    return super unless parameters
-    scope.joins(:person).where(people: { preferred_contact_method: parameters.keys })
+    return super if parameters[PARAM_NAME].blank?
+    scope.joins(:person).where(people: { preferred_contact_method: parameters[PARAM_NAME].keys })
   end
 end

app/filters/contribution_type_filter.rb

@@ -1,8 +1,11 @@
 class ContributionTypeFilter
+  PARAM_NAME = 'ContributionType'
+  ALLOWED_PARAMS = {PARAM_NAME => {}}
+
   def self.filter_grouping
     { name: 'Contribution Types', filter_options: [
-      { id: 'ContributionType[Ask]', name: 'Ask' },
-      { id: 'ContributionType[Offer]', name: 'Offer' }
+      { id: "#{PARAM_NAME}[Ask]", name: 'Ask' },
+      { id: "#{PARAM_NAME}[Offer]", name: 'Offer' }
     ]}
   end
   ALL_ALLOWED_TYPES = ['Ask', 'Offer'].freeze
@@ -14,7 +17,7 @@ def initialize(params)
   end
 
   def scopes
-    classes = parameters.blank? ? ALL_ALLOWED_TYPES : parameters.keys
+    classes = parameters.blank? || parameters[PARAM_NAME].blank? ? ALL_ALLOWED_TYPES : parameters[PARAM_NAME].keys
     classes.intersection(ALL_ALLOWED_TYPES).map do |type|
       type.constantize.matchable
     end

app/filters/service_area_filter.rb

@@ -1,4 +1,7 @@
 class ServiceAreaFilter < BaseFilter
+  PARAM_NAME = 'ServiceArea'
+  ALLOWED_PARAMS = {PARAM_NAME => {}}
+
   def self.filter_grouping
     {
       name: 'Service Areas',
@@ -7,7 +10,7 @@ def self.filter_grouping
   end
 
   def filter(scope)
-    return super unless parameters
-    scope.where(service_area_id: parameters.keys)
+    return super if parameters[PARAM_NAME].blank?
+    scope.where(service_area_id: parameters[PARAM_NAME].keys)
   end
 end

app/filters/urgency_filter.rb

@@ -0,0 +1,16 @@
+class UrgencyFilter < BaseFilter
+  PARAM_NAME = 'UrgencyLevel'
+  ALLOWED_PARAMS = {PARAM_NAME => {}}
+
+  def self.filter_grouping
+    {
+      name: 'Urgency',
+      filter_options: FilterOptionBlueprint.render_as_hash(UrgencyLevel::TYPES)
+    }
+  end
+
+  def filter(scope)
+    return super if parameters[PARAM_NAME].blank?
+    scope.where(urgency_level_id: parameters[PARAM_NAME].keys)
+  end
+end

app/models/browse_filter.rb

@@ -3,16 +3,15 @@
 # BrowseFilter lets the browse page filter contributions by parameters, delegating much of the actual filtering
 # to the classes listed in BrowseFilter::FILTER_CLASSES
 class BrowseFilter
-  FILTERS = {
-    'Category' => CategoryFilter,
-    'ServiceArea' => ServiceAreaFilter,
-    'ContactMethod' => ContactMethodFilter,
-    'ContributionType' => ContributionTypeFilter
-    # 'UrgencyLevel' => UrgencyLevelFilter
-  }.freeze
-  FILTER_CLASSES = FILTERS.values.freeze
-  ALLOWED_PARAMS = FILTERS.keys.each_with_object({}) do |key, hash|
-    hash[key] = {}
+  FILTER_CLASSES = [
+    CategoryFilter,
+    ServiceAreaFilter,
+    ContactMethodFilter,
+    ContributionTypeFilter,
+    UrgencyFilter
+  ].freeze
+  ALLOWED_PARAMS = FILTER_CLASSES.each_with_object({}) do |filter, hash|
+    hash.merge! filter::ALLOWED_PARAMS
   end.freeze
 
   attr_reader :parameters
@@ -29,16 +28,16 @@ def initialize(parameters)
   def contributions
     # ContributionTypeFilter is special and needs to come first because of Single Table Inheretence
     # Currently, the only other option seemed to be pulling in a gem that supports UNION queries in SQL
-    starting_relations = ContributionTypeFilter.new(parameters['ContributionType']).scopes
+    starting_relations = ContributionTypeFilter.new(parameters).scopes
 
     # So using whatever relations ContributionTypeFilter gives us (unmatched asks, unmatched offers, etc.)
-    @contributions ||= FILTERS.reduce(starting_relations) do |resulting_relations, (filter_name, klass)|
+    @contributions ||= FILTER_CLASSES.reduce(starting_relations) do |resulting_relations, filter_class|
       # Skip ContributionTypeFilter because we've already used it
-      next resulting_relations if klass == ContributionTypeFilter
+      next resulting_relations if filter_class == ContributionTypeFilter
 
       # then filter the relations further based on the rules in each class for doing so
       resulting_relations.map do |scope|
-        klass.new(parameters[filter_name]).filter(scope)
+        filter_class.new(parameters).filter(scope)
       end
     end.flatten
   end