Accept multiple attributes #30

lib/active_form.rb

@@ -2,7 +2,8 @@
 require 'active_form/form'
 require 'active_form/form_collection'
 require 'active_form/form_definition'
-require 'active_form/too_many_records'
+require 'active_form/errors'
+require 'active_form/multiparameter_attribute'
 require 'active_form/view_helpers'
 
 module ActiveForm

lib/active_form/base.rb

@@ -16,13 +16,21 @@ def initialize(model)
     end
 
     def submit(params)
+      multi_parameter_attributes  = []
+
       params.each do |key, value|
-        if nested_params?(value)
+        if key.to_s.include?("(")
+          multi_parameter_attributes << [ key, value ]
+        elsif nested_params?(value)
           fill_association_with_attributes(key, value)
         else
           send("#{key}=", value)
         end
       end
+
+      if multi_parameter_attributes.present?
+        assign_multiparameter_attributes(multi_parameter_attributes)
+      end
     end
 
     def get_model(assoc_name)
@@ -164,6 +172,49 @@ def collect_errors_from(validatable_object)
         errors.add(key, error)
       end
     end
+
+    def assign_multiparameter_attributes(pairs)
+      execute_callstack_for_multiparameter_attributes(
+        extract_callstack_for_multiparameter_attributes(pairs)
+      )
+    end
+
+    def execute_callstack_for_multiparameter_attributes(callstack)
+      errors = []
+      callstack.each do |name, values_with_empty_parameters|
+        begin
+          send("#{name}=", MultiparameterAttribute.new(self, name, values_with_empty_parameters).read_value)
+        rescue => ex
+          errors << AttributeAssignmentError.new("error on assignment #{values_with_empty_parameters.values.inspect} to #{name} (#{ex.message})", ex, name)
+        end
+      end
+      if errors.present?
+        error_descriptions = errors.map { |ex| ex.message }.join(",")
+        raise MultiparameterAssignmentErrors.new(errors), "#{errors.size} error(s) on assignment of multiparameter attributes [#{error_descriptions}]"
+      end
+    end
+
+    def extract_callstack_for_multiparameter_attributes(pairs)
+      attributes = {}
+
+      pairs.each do |(multiparameter_name, value)|
+        attribute_name = multiparameter_name.split("(").first
+        attributes[attribute_name] ||= {}
+
+        parameter_value = value.empty? ? nil : type_cast_attribute_value(multiparameter_name, value)
+        attributes[attribute_name][find_parameter_position(multiparameter_name)] ||= parameter_value
+      end
+
+      attributes
+    end
+
+    def type_cast_attribute_value(multiparameter_name, value)
+      multiparameter_name =~ /\([0-9]*([if])\)/ ? value.send("to_" + $1) : value
+    end
+
+    def find_parameter_position(multiparameter_name)
+      multiparameter_name.scan(/\(([0-9]*).*\)/).first.first.to_i
+    end
   end
 
 end

lib/active_form/errors.rb

@@ -0,0 +1,22 @@
+module ActiveForm
+  class TooManyRecords < RuntimeError;end
+
+  class AttributeAssignmentError < RuntimeError
+    attr_reader :exception, :attribute
+    def initialize(message, exception, attribute)
+      super(message)
+      @exception = exception
+      @attribute = attribute
+    end
+  end
+
+  # Raised when there are multiple errors while doing a mass assignment through the +attributes+
+  # method. The exception has an +errors+ property that contains an array of AttributeAssignmentError
+  # objects, each corresponding to the error while assigning to an attribute.
+  class MultiparameterAssignmentErrors < RuntimeError
+    attr_reader :errors
+    def initialize(errors)
+      @errors = errors
+    end
+  end
+end

lib/active_form/form.rb

@@ -82,13 +82,19 @@ def submit(params)
         @model = parent.send("build_#{association_name}") unless call_reject_if(params_for_current_scope(params))
       end
 
+      multi_parameter_attributes  = []
+
       params.each do |key, value|
-        if nested_params?(value)
+        if key.to_s.include?("(")
+          multi_parameter_attributes << [ key, value ]
+        elsif nested_params?(value)
           fill_association_with_attributes(key, value)
         else
           model.send("#{key}=", value)
         end
       end
+
+      assign_multiparameter_attributes(multi_parameter_attributes) if multi_parameter_attributes.present?
     end
 
     def get_model(assoc_name)
@@ -199,9 +205,53 @@ def collect_errors_from(validatable_object)
         else
           attribute
         end
+        puts "adding #{key} error: #{error} from #{validatable_object}"
         errors.add(key, error)
       end
     end
+
+    def assign_multiparameter_attributes(pairs)
+      execute_callstack_for_multiparameter_attributes(
+        extract_callstack_for_multiparameter_attributes(pairs)
+      )
+    end
+
+    def execute_callstack_for_multiparameter_attributes(callstack)
+      errors = []
+      callstack.each do |name, values_with_empty_parameters|
+        begin
+          send("#{name}=", MultiparameterAttribute.new(self, name, values_with_empty_parameters).read_value)
+        rescue => ex
+          errors << AttributeAssignmentError.new("error on assignment #{values_with_empty_parameters.values.inspect} to #{name} (#{ex.message})", ex, name)
+        end
+      end
+      if errors.present?
+        error_descriptions = errors.map { |ex| ex.message }.join(",")
+        raise MultiparameterAssignmentErrors.new(errors), "#{errors.size} error(s) on assignment of multiparameter attributes [#{error_descriptions}]"
+      end
+    end
+
+    def extract_callstack_for_multiparameter_attributes(pairs)
+      attributes = {}
+
+      pairs.each do |(multiparameter_name, value)|
+        attribute_name = multiparameter_name.split("(").first
+        attributes[attribute_name] ||= {}
+
+        parameter_value = value.empty? ? nil : type_cast_attribute_value(multiparameter_name, value)
+        attributes[attribute_name][find_parameter_position(multiparameter_name)] ||= parameter_value
+      end
+
+      attributes
+    end
+
+    def type_cast_attribute_value(multiparameter_name, value)
+      multiparameter_name =~ /\([0-9]*([if])\)/ ? value.send("to_" + $1) : value
+    end
+
+    def find_parameter_position(multiparameter_name)
+      multiparameter_name.scan(/\(([0-9]*).*\)/).first.first.to_i
+    end
   end
 
 end

lib/active_form/multiparameter_attribute.rb

@@ -0,0 +1,93 @@
+module ActiveForm
+  class MultiparameterAttribute #:nodoc:
+    attr_reader :object, :name, :values, :column
+
+    def initialize(object, name, values)
+      @object = object
+      @name   = name
+      @values = values
+    end
+
+    def read_value
+      return if values.values.compact.empty?
+
+      @column = object.model.class.reflect_on_aggregation(name.to_sym) || object.model.column_for_attribute(name)
+      klass   = column.klass
+
+      if klass == Time
+        read_time
+      elsif klass == Date
+        read_date
+      else
+        read_other(klass)
+      end
+    end
+
+    private
+
+    def instantiate_time_object(set_values)
+      Time.zone.local(*set_values)
+    end
+
+    def read_time
+      # If column is a :time (and not :date or :timestamp) there is no need to validate if
+      # there are year/month/day fields
+      if column.type == :time
+        # if the column is a time set the values to their defaults as January 1, 1970, but only if they're nil
+        { 1 => 1970, 2 => 1, 3 => 1 }.each do |key,value|
+          values[key] ||= value
+        end
+      else
+        # else column is a timestamp, so if Date bits were not provided, error
+        validate_required_parameters!([1,2,3])
+
+        # If Date bits were provided but blank, then return nil
+        return if blank_date_parameter?
+      end
+
+      max_position = extract_max_param(6)
+      set_values   = values.values_at(*(1..max_position))
+      # If Time bits are not there, then default to 0
+      (3..5).each { |i| set_values[i] = set_values[i].presence || 0 }
+      instantiate_time_object(set_values)
+    end
+
+    def read_date
+      return if blank_date_parameter?
+      set_values = values.values_at(1,2,3)
+      begin
+        Date.new(*set_values)
+      rescue ArgumentError # if Date.new raises an exception on an invalid date
+        instantiate_time_object(set_values).to_date # we instantiate Time object and convert it back to a date thus using Time's logic in handling invalid dates
+      end
+    end
+
+    def read_other(klass)
+      max_position = extract_max_param
+      positions    = (1..max_position)
+      validate_required_parameters!(positions)
+
+      set_values = values.values_at(*positions)
+      klass.new(*set_values)
+    end
+
+    # Checks whether some blank date parameter exists. Note that this is different
+    # than the validate_required_parameters! method, since it just checks for blank
+    # positions instead of missing ones, and does not raise in case one blank position
+    # exists. The caller is responsible to handle the case of this returning true.
+    def blank_date_parameter?
+      (1..3).any? { |position| values[position].blank? }
+    end
+
+    # If some position is not provided, it errors out a missing parameter exception.
+    def validate_required_parameters!(positions)
+      if missing_parameter = positions.detect { |position| !values.key?(position) }
+        raise ArgumentError.new("Missing Parameter - #{name}(#{missing_parameter})")
+      end
+    end
+
+    def extract_max_param(upper_cap = 100)
+      [values.keys.max, upper_cap].min
+    end
+  end
+end

test/dummy/app/forms/project_form.rb

@@ -1,8 +1,8 @@
 class ProjectForm < ActiveForm::Base
-  attributes :name, :description, :owner_id
+  attributes :name, :description, :owner_id, :published_at
 
   association :tasks do
-    attributes :name, :description, :done
+    attributes :name, :description, :done, :finished_at
 
     association :sub_tasks do
       attributes :name, :description, :done

test/dummy/db/migrate/20141227163700_add_published_at_to_projects.rb

@@ -0,0 +1,5 @@
+class AddPublishedAtToProjects < ActiveRecord::Migration
+  def change
+    add_column :projects, :published_at, :datetime
+  end
+end

test/dummy/db/migrate/20141227165333_add_finished_at_to_tasks.rb

@@ -0,0 +1,5 @@
+class AddFinishedAtToTasks < ActiveRecord::Migration
+  def change
+    add_column :tasks, :finished_at, :datetime
+  end
+end

test/dummy/db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20140821074917) do
+ActiveRecord::Schema.define(version: 20141227165333) do
 
   create_table "answers", force: true do |t|
     t.text     "content"
@@ -110,6 +110,7 @@
     t.datetime "created_at"
     t.datetime "updated_at"
     t.integer  "owner_id"
+    t.datetime "published_at"
   end
 
   create_table "questions", force: true do |t|
@@ -169,6 +170,7 @@
     t.datetime "created_at"
     t.datetime "updated_at"
     t.integer  "assignment_id"
+    t.datetime "finished_at"
   end
 
   add_index "tasks", ["assignment_id"], name: "index_tasks_on_assignment_id"