Class: Hold::Sequel::PropertyMapper::ForeignKey

Inherits:
Hold::Sequel::PropertyMapper show all
Defined in:
lib/hold/sequel/property_mapper/foreign_key.rb

Overview

Maps to an associated object which is fetched by id from a target repository using a foriegn key column

Instance Attribute Summary collapse

Attributes inherited from Hold::Sequel::PropertyMapper

#property, #property_name, #repository

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Hold::Sequel::PropertyMapper

#post_delete, #post_insert, #post_update, #pre_delete

Constructor Details

#initialize(repo, property_name, options) ⇒ ForeignKey

auto_store_new: where the value for this property is an object without an ID,

automatically store_new the object in the target_repo before trying to store
the object in question with this foreign key property. In the absence of this
setting, values without an ID will cause an exception



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 18

def initialize(repo, property_name, options)
  super(repo, property_name)

  @table = options[:table] || @repository.main_table
  @column_name = options[:column_name] || :"#{property_name}_id"
  @column_alias = :"#{@table}_#{@column_name}"
  @column_qualified = Sequel::SQL::QualifiedIdentifier.new(@table, @column_name)
  @columns_aliases_and_tables_for_select = [
    [@column_qualified],
    [Sequel::SQL::AliasedExpression.new(@column_qualified, @column_alias)],
    [@table]
  ]

  @auto_store_new = options[:auto_store_new] || false
  @model_class = options[:model_class] or raise ArgumentError
end

Instance Attribute Details

#auto_store_new ⇒ Object (readonly)

Returns the value of attribute auto_store_new.



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 11

def auto_store_new
  @auto_store_new
end

#column_alias ⇒ Object (readonly)

Returns the value of attribute column_alias.



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 11

def column_alias
  @column_alias
end

#column_name ⇒ Object (readonly)

Returns the value of attribute column_name.



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 11

def column_name
  @column_name
end

#column_qualified ⇒ Object (readonly)

Returns the value of attribute column_qualified.



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 11

def column_qualified
  @column_qualified
end

#columns_aliases_and_tables_for_select ⇒ Object (readonly)

Returns the value of attribute columns_aliases_and_tables_for_select.



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 11

def columns_aliases_and_tables_for_select
  @columns_aliases_and_tables_for_select
end

#model_class ⇒ Object (readonly)

Returns the value of attribute model_class.



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 11

def model_class
  @model_class
end

#table ⇒ Object (readonly)

Returns the value of attribute table.



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 11

def table
  @table
end

#target_repo ⇒ Object

Returns the value of attribute target_repo.



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 9

def target_repo
  @target_repo
end

Class Method Details

.setter_dependencies_for(options = {}) ⇒ Object 



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 4

def self.setter_dependencies_for(options={})
  features = [*options[:model_class]].map {|klass| [:get_class, klass]}
  {:target_repo => [Hold::IdentitySetRepository, *features]}
end

Instance Method Details

#build_insert_row(entity, table, row, id = nil) ⇒ Object Also known as: build_update_row 



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 57

def build_insert_row(entity, table, row, id=nil)
  if @table == table && entity.has_key?(@property_name)
    value = entity[@property_name]
    row[@column_name] = value && value.id
  end
end

#ensure_value_has_id_where_present(value) ⇒ Object 



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 39

def ensure_value_has_id_where_present(value)
  if value && !value.id
    if @auto_store_new
      target_repo.store_new(value)
    else
      raise "value for ForeignKey mapped property #{@property_name} has no id, and :auto_store_new not specified"
    end
  end
end

#load_value(row, id = nil, properties = nil) ⇒ Object 



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 35

def load_value(row, id=nil, properties=nil)
  fkey = row[@column_alias] and target_repo.get_by_id(fkey, :properties => properties)
end

#load_values(rows, ids = nil, properties = nil, &b) ⇒ Object

efficient batch load which takes advantage of get_many_by_ids on the target repo



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 85

def load_values(rows, ids=nil, properties=nil, &b)
  fkeys = rows.map {|row| row[@column_alias]}
  non_nil_fkeys = fkeys.compact
  non_nil_fkey_results = if non_nil_fkeys.empty? then [] else
    target_repo.get_many_by_ids(non_nil_fkeys, :properties => properties)
  end
  fkeys.each_with_index do |fkey, index|
    yield(fkey ? non_nil_fkey_results.shift : nil, index)
  end
end

#make_filter(value, columns_mapped_to = nil) ⇒ Object

for now ignoring the columns_mapped_to, since Identity mapper is the only one for which this matters at present



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 68

def make_filter(value, columns_mapped_to=nil)
  {@column_qualified => value && value.id}
end

#make_filter_by_id(id, columns_mapped_to = nil) ⇒ Object 



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 76

def make_filter_by_id(id, columns_mapped_to=nil)
  {@column_qualified => id}
end

#make_filter_by_ids(ids, columns_mapped_to = nil) ⇒ Object 



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 80

def make_filter_by_ids(ids, columns_mapped_to=nil)
  {@column_qualified => ids}
end

#make_multi_filter(values, columns_mapped_to = nil) ⇒ Object 



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 72

def make_multi_filter(values, columns_mapped_to=nil)
  {@column_qualified => values.map {|v| v.id}}
end

#pre_insert(entity) ⇒ Object 



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 49

def pre_insert(entity)
  ensure_value_has_id_where_present(entity[@property_name])
end

#pre_update(entity, update_entity) ⇒ Object 



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# File 'lib/hold/sequel/property_mapper/foreign_key.rb', line 53

def pre_update(entity, update_entity)
  ensure_value_has_id_where_present(update_entity[@property_name])
end