Class: Rack::Reducer::Reduction

Inherits:
Object
  • Object
show all
Defined in:
lib/rack/reducer/reduction.rb

Overview

call ‘reduce` on a params hash, filtering data via lambdas with matching keyword arguments

Instance Method Summary collapse

Constructor Details

#initialize(dataset, *filters) ⇒ Reduction

Returns a new instance of Reduction.



12
13
14
15
 
# File 'lib/rack/reducer/reduction.rb', line 12

def initialize(dataset, *filters)
  @dataset = dataset
  @filters = filters
end

Instance Method Details

#apply(params) ⇒ Object

Run @filters against the params argument

Parameters:

  • params (Hash, ActionController::Parameters, nil) —

    a Rack-compatible params hash

Returns:

  • @dataset with the matching filters applied



21
22
23
24
25
26
27
28
29
30
31
32
33
 
# File 'lib/rack/reducer/reduction.rb', line 21

def apply(params)
  return @dataset if !params || params.empty?

  symbolized_params = params.to_unsafe_h.symbolize_keys
  @filters.reduce(@dataset) do |data, filter|
    next data unless filter.satisfies?(symbolized_params)

    data.instance_exec(
      **symbolized_params.slice(*filter.all_argument_names),
      &filter
    )
  end
end