Class: MR::ReadModel::FromSubqueryExpression

Inherits:
Object
  • Object
show all
Defined in:
lib/mr/read_model/query_expression.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(&block) ⇒ FromSubqueryExpression

Returns a new instance of FromSubqueryExpression.

Raises:

  • (ArgumentError) 


108
109
110
111
 
# File 'lib/mr/read_model/query_expression.rb', line 108

def initialize(&block)
  raise ArgumentError, "a block must be provided" unless block
  @subquery_block = block
end

Instance Attribute Details

#subquery_block ⇒ Object (readonly)

Returns the value of attribute subquery_block.



106
107
108
 
# File 'lib/mr/read_model/query_expression.rb', line 106

def subquery_block
  @subquery_block
end

Instance Method Details

#ar_relation(params = nil) ⇒ Object 



129
130
131
 
# File 'lib/mr/read_model/query_expression.rb', line 129

def ar_relation(params = nil)
  self.record_class.scoped.from(self.from_subquery.build_sql(params))
end

#default_find_attr ⇒ Object

Raises:



124
125
126
127
 
# File 'lib/mr/read_model/query_expression.rb', line 124

def default_find_attr
  raise NoFindAttrError, "a `find_attr` has to be specified " \
                         "when using a from subquery"
end

#from_subquery ⇒ Object

lazy-build FromSubquery so its block is not evaluated until the read model query method is called, cache it so it doesn’t have to be rebuilt for every query call



116
117
118
 
# File 'lib/mr/read_model/query_expression.rb', line 116

def from_subquery
  @from_subquery ||= FromSubquery.new(&self.subquery_block)
end

#record_class ⇒ Object 



120
121
122
 
# File 'lib/mr/read_model/query_expression.rb', line 120

def record_class
  self.from_subquery.record_class
end