Class: MongoQL::Stage::Lookup

Inherits:
MongoQL::Stage show all
Defined in:
lib/mongo_ql/stage/lookup.rb

Defined Under Namespace

Classes: NestedPipelineVars

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(ctx, from, condition = nil, on: nil, as: nil, &block) ⇒ Lookup

Returns a new instance of Lookup.



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# File 'lib/mongo_ql/stage/lookup.rb', line 38

def initialize(ctx, from, condition = nil, on: nil, as: nil, &block)
  @ctx       = ctx
  @from      = collection_name(from)
  @as        = new_array_name(as)
  @nested_pipeline_block = block

  if has_nested_pipeline?
    @let_vars = NestedPipelineVars.new
    @nested_pipeline = eval_nested_pipeline
  else
    @condition = condition_ast(condition || on)
  end
end

Instance Attribute Details

#as ⇒ Object

Returns the value of attribute as.



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# File 'lib/mongo_ql/stage/lookup.rb', line 35

def as
  @as
end

#condition ⇒ Object

Returns the value of attribute condition.



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# File 'lib/mongo_ql/stage/lookup.rb', line 35

def condition
  @condition
end

#ctx ⇒ Object

Returns the value of attribute ctx.



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# File 'lib/mongo_ql/stage/lookup.rb', line 35

def ctx
  @ctx
end

#from ⇒ Object

Returns the value of attribute from.



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# File 'lib/mongo_ql/stage/lookup.rb', line 35

def from
  @from
end

#let_vars ⇒ Object

Returns the value of attribute let_vars.



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# File 'lib/mongo_ql/stage/lookup.rb', line 35

def let_vars
  @let_vars
end

#nested_pipeline ⇒ Object

Returns the value of attribute nested_pipeline.



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# File 'lib/mongo_ql/stage/lookup.rb', line 35

def nested_pipeline
  @nested_pipeline
end

#nested_pipeline_block ⇒ Object

Returns the value of attribute nested_pipeline_block.



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# File 'lib/mongo_ql/stage/lookup.rb', line 35

def nested_pipeline_block
  @nested_pipeline_block
end

Instance Method Details

#to_ast ⇒ Object 



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# File 'lib/mongo_ql/stage/lookup.rb', line 52

def to_ast
  lookup_expr = { "from" => from, "as" => as }
  if has_nested_pipeline?
    lookup_expr["pipeline"] = nested_pipeline
    lookup_expr["let"]      = let_vars.vars
  else
    lookup_expr = lookup_expr.merge(condition)
  end
  ast = { "$lookup" => lookup_expr }
  MongoQL::Utils.deep_transform_values(ast, &MongoQL::EXPRESSION_TO_AST_MAPPER)
end