module ActiveScaffold
# Provides support for param hashes assumed to be model attributes.
# Support is primarily needed for creating/editing associated records using a nested hash structure.
#
# Paradigm Params Hash (should write unit tests on this):
# params[:record] = {
# # a simple record attribute
# 'name' => 'John',
# # a plural association hash
# 'roles' => {
# # associate with an existing role
# '5' => {'id' => 5}
# # associate with an existing role and edit it
# '6' => {'id' => 6, 'name' => 'designer'}
# # create and associate a new role
# '124521' => {'name' => 'marketer'}
# }
# # a singular association hash
# 'location' => {'id' => 12, 'city' => 'New York'}
# }
#
# Simpler association structures are also supported, like:
# params[:record] = {
# # a simple record attribute
# 'name' => 'John',
# # a plural association ... all ids refer to existing records
# 'roles' => ['5', '6'],
# # a singular association ... all ids refer to existing records
# 'location' => '12'
# }
module AttributeParams
protected
# Takes attributes (as from params[:record]) and applies them to the parent_record. Also looks for
# association attributes and attempts to instantiate them as associated objects.
#
# This is a secure way to apply params to a record, because it's based on a loop over the columns
# set. The columns set will not yield unauthorized columns, and it will not yield unregistered columns.
def update_record_from_params(parent_record, columns, attributes)
crud_type = parent_record.new_record? ? :create : :update
return parent_record unless parent_record.authorized_for?(:crud_type => crud_type)
multi_parameter_attributes = {}
attributes.each do |k, v|
next unless k.include? '('
column_name = k.split('(').first.to_sym
multi_parameter_attributes[column_name] ||= []
multi_parameter_attributes[column_name] << [k, v]
end
columns.each :for => parent_record, :crud_type => crud_type, :flatten => true do |column|
# Set any passthrough parameters that may be associated with this column (ie, file column "keep" and "temp" attributes)
unless column.params.empty?
column.params.each{|p| parent_record.send("#{p}=", attributes[p]) if attributes.has_key? p}
end
if multi_parameter_attributes.has_key? column.name
parent_record.send(:assign_multiparameter_attributes, multi_parameter_attributes[column.name])
elsif attributes.has_key? column.name
value = column_value_from_param_value(parent_record, column, attributes[column.name])
# we avoid assigning a value that already exists because otherwise has_one associations will break (AR bug in has_one_association.rb#replace)
parent_record.send("#{column.name}=", value) unless parent_record.send(column.name) == value
# plural associations may not actually appear in the params if all of the options have been unselected or cleared away.
# the "form_ui" check is necessary, becuase without it we have problems
# with subforms. the UI cuts out deep associations, which means they're not present in the
# params even though they're in the columns list. the result is that associations were being
# emptied out way too often.
elsif column.form_ui and column.plural_association?
parent_record.send("#{column.name}=", [])
end
end
if parent_record.new_record?
parent_record.class.reflect_on_all_associations.each do |a|
next unless [:has_one, :has_many].include?(a.macro) and not a.options[:through]
next unless association_proxy = parent_record.send(a.name)
raise ActiveScaffold::ReverseAssociationRequired, "Association #{a.name}: In order to support :has_one and :has_many where the parent record is new and the child record(s) validate the presence of the parent, ActiveScaffold requires the reverse association (the belongs_to)." unless a.reverse
association_proxy = [association_proxy] if a.macro == :has_one
association_proxy.each { |record| record.send("#{a.reverse}=", parent_record) }
end
end
parent_record
end
def manage_nested_record_from_params(parent_record, column, attributes)
record = find_or_create_for_params(attributes, column, parent_record)
if record
record_columns = active_scaffold_config_for(column.association.klass).subform.columns
update_record_from_params(record, record_columns, attributes)
record.unsaved = true
end
record
end
def column_value_from_param_value(parent_record, column, value)
# convert the value, possibly by instantiating associated objects
if value.is_a?(Hash)
column_value_from_param_hash_value(parent_record, column, value)
else
column_value_from_param_simple_value(parent_record, column, value)
end
end
def column_value_from_param_simple_value(parent_record, column, value)
if column.singular_association?
# it's a single id
column.association.klass.find(value) if value and not value.empty?
elsif column.plural_association?
# it's an array of ids
if value and not value.empty?
ids = value.select {|id| id.respond_to?(:empty?) ? !id.empty? : true}
ids.empty? ? [] : column.association.klass.find(ids)
end
elsif column.column && column.column.number? && [:i18n_number, :currency].include?(column.options[:format])
self.class.i18n_number_to_native_format(value)
else
# convert empty strings into nil. this works better with 'null => true' columns (and validations),
# and 'null => false' columns should just convert back to an empty string.
# ... but we can at least check the ConnectionAdapter::Column object to see if nulls are allowed
value = nil if value.is_a? String and value.empty? and !column.column.nil? and column.column.null
value
end
end
def column_value_from_param_hash_value(parent_record, column, value)
# this is just for backwards compatibility. we should clean this up in 2.0.
if column.form_ui == :select
ids = if column.singular_association?
value[:id]
else
value.values.collect {|hash| hash[:id]}
end
(ids and not ids.empty?) ? column.association.klass.find(ids) : nil
elsif column.singular_association?
manage_nested_record_from_params(parent_record, column, value)
elsif column.plural_association?
value.collect {|key_value_pair| manage_nested_record_from_params(parent_record, column, key_value_pair[1])}.compact
else
value
end
end
# Attempts to create or find an instance of klass (which must be an ActiveRecord object) from the
# request parameters given. If params[:id] exists it will attempt to find an existing object
# otherwise it will build a new one.
def find_or_create_for_params(params, parent_column, parent_record)
current = parent_record.send(parent_column.name)
klass = parent_column.association.klass
return nil if parent_column.show_blank_record and attributes_hash_is_empty?(params, klass)
if params.has_key? :id
# modifying the current object of a singular association
if current and current.is_a? ActiveRecord::Base and current.id.to_s == params[:id]
return current
# modifying one of the current objects in a plural association
elsif current and current.respond_to?(:any?) and current.any? {|o| o.id.to_s == params[:id]}
return current.detect {|o| o.id.to_s == params[:id]}
# attaching an existing but not-current object
else
return klass.find(params[:id])
end
else
if klass.authorized_for?(:crud_type => :create)
if parent_column.singular_association?
return parent_record.send("build_#{parent_column.name}")
else
return parent_record.send(parent_column.name).build
end
end
end
end
# Determines whether the given attributes hash is "empty".
# This isn't a literal emptiness - it's an attempt to discern whether the user intended it to be empty or not.
def attributes_hash_is_empty?(hash, klass)
ignore_column_types = [:boolean]
hash.all? do |key,value|
# convert any possible multi-parameter attributes like 'created_at(5i)' to simply 'created_at'
parts = key.to_s.split('(')
#old style date form management... ignore them too
ignore_column_types = [:boolean, :datetime, :date, :time] if parts.length > 1
column_name = parts.first
column = klass.columns_hash[column_name]
# booleans and datetimes will always have a value. so we ignore them when checking whether the hash is empty.
# this could be a bad idea. but the current situation (excess record entry) seems worse.
next true if column and ignore_column_types.include?(column.type)
# defaults are pre-filled on the form. we can't use them to determine if the user intends a new row.
next true if column and value == column.default.to_s
if value.is_a?(Hash)
attributes_hash_is_empty?(value, klass)
elsif value.is_a?(Array)
value.any? {|id| id.respond_to?(:empty?) ? !id.empty? : true}
else
value.respond_to?(:empty?) ? value.empty? : false
end
end
end
end
end