Module: Iudex::DA::Filters::FactoryHelper

Includes:
Filter::KeyHelper
Defined in:
lib/iudex-da/factory_helper.rb

Overview

Mixin FilterChainFactory helper methods

Instance Method Summary collapse

Methods included from Filter::KeyHelper

lookup_key

Instance Method Details

#create_read_filter(*args) ⇒ Object

Create a ReadFilter given the provided options.

Options

:fields

The Array of fields (Symbol or Key) to read from the database.

The positional parameters equivalent to ( :fields ) as defined above is also supported but deprecated.



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# File 'lib/iudex-da/factory_helper.rb', line 111

def create_read_filter( *args )
  opts = args.last.is_a?( Hash ) ? args.pop.dup : {}
  opts[ :fields ]        ||= args.shift #deprecated

  ReadFilter.new( data_source, field_mapper( opts[ :fields ] ) )
end

#create_update_filter(*args) ⇒ Object

Create an UpdateFilter given the provided options.

Options

:fields

The Array of fields (Symbol or Key) to (re-)read from the database and update. The required :uhash field is included automatically.

:max_retries

Maximum number of retries not including the initial attempt, in case of a database conflict (Default: 3)

:isolation_level

A transaction isolation constant as defined in java.sql.Connection (Default: REPEATABLE_READ 0x04)

:on_content

Filter option for current (content) UniMap.

:on_ref_update

Filter option for REFERENCES that are already existing in the database

:on_ref_new

Filter option for REFERENCES that are new (not found in db).

:on_referer

Filter option for the REFERER to the current content.

The positional parameters equivalent to ( :fields, :on_content, :on_ref_update, :on_ref_new ) as defined above are also supported but deprecated.

Filter options

Each of the on_* filter options defined above may take a value of a Filter, Array of filters or a Symbol value. The following symbol values are special, all other Symbol values are passed as the :filters option to create_chain, and is interpreted as a method name.

:merge

The default behavior of merging the in-memory state with the current database state. This is equivalent to providing a NoOpFilter.

:ignore

Do not update this element. This is equivalent to providing a filter that always rejects, but faster since it need not read the value from the db.



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# File 'lib/iudex-da/factory_helper.rb', line 81

def create_update_filter( *args )
  opts = args.last.is_a?( Hash ) ? args.pop.dup : {}

  opts[ :fields ]        ||= args.shift #deprecated
  opts[ :on_content ]    ||= args.shift
  opts[ :on_ref_update ] ||= args.shift
  opts[ :on_ref_new    ] ||= args.shift

  f = UpdateFilter.new( data_source, field_mapper( opts[ :fields ] ) )
  updater_chain( opts[:on_ref_update]) { |c| f.update_ref_filter = c }
  updater_chain( opts[ :on_ref_new ] ) { |c| f.new_ref_filter    = c }
  updater_chain( opts[ :on_content ] ) { |c| f.content_filter    = c }
  updater_chain( opts[ :on_referer ] ) { |c| f.referer_filter    = c }

  f.max_retries     = opts[ :max_retries ]   if opts[ :max_retries ]
  f.isolation_level = opts[:isolation_level] if opts[:isolation_level]

  f
end

#data_source ⇒ Object

Lazy initialize DataSource



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# File 'lib/iudex-da/factory_helper.rb', line 30

def data_source
  @data_source ||= PoolDataSourceFactory.new.create
end

#field_mapper(fields) ⇒ Object 



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# File 'lib/iudex-da/factory_helper.rb', line 118

def field_mapper( fields )
  fields = keys( ( [ :uhash ] + fields ).flatten.compact )
  ContentMapper.new( fields )
end

#updater_chain(v, &block) ⇒ Object 



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# File 'lib/iudex-da/factory_helper.rb', line 123

def updater_chain( v, &block )
  if v.is_a?( Iudex::Filter::Filter )
    block.call( v )
  elsif v == :merge
    block.call( UpdateFilter::DEFAULT_MERGE )
  elsif v == :ignore
    block.call( nil )
  else
    create_chain( :filters => v, &block )
  end
end