Class: Chicago::Flow::TransformationChain

Inherits:
Object
  • Object
show all
Defined in:
lib/chicago/flow/transformation_chain.rb

Instance Method Summary collapse

Constructor Details

#initialize(*transforms) ⇒ TransformationChain

Returns a new instance of TransformationChain.



4
5
6
 
# File 'lib/chicago/flow/transformation_chain.rb', line 4

def initialize(*transforms)
  @transforms = transforms
end

Instance Method Details

#downstream_fields(fields) ⇒ Object 



28
29
30
 
# File 'lib/chicago/flow/transformation_chain.rb', line 28

def downstream_fields(fields)
  @transforms.inject(fields) {|t| t.downstream_fields(fields) }
end

#flush ⇒ Object 



18
19
20
21
22
 
# File 'lib/chicago/flow/transformation_chain.rb', line 18

def flush
  @transforms.inject([]) do |rows, transform|
    process_rows(rows, transform) + transform.flush
  end
end

#output_streams ⇒ Object 



8
9
10
 
# File 'lib/chicago/flow/transformation_chain.rb', line 8

def output_streams
  @transforms.inject([]) {|s, t| s | t.output_streams }
end

#process(row) ⇒ Object 



12
13
14
15
16
 
# File 'lib/chicago/flow/transformation_chain.rb', line 12

def process(row)
  @transforms.inject([row]) do |rows, transform|
    process_rows(rows, transform)
  end
end

#upstream_fields(fields) ⇒ Object 



24
25
26
 
# File 'lib/chicago/flow/transformation_chain.rb', line 24

def upstream_fields(fields)
  @transforms.inject(fields) {|t| t.upstream_fields(fields) }
end