Class: Pura::Processing::Processor

Inherits:
Object
  • Object
show all
Defined in:
lib/pura/processing/processor.rb

Overview

Abstract class inherited by individual processors.

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(accumulator = nil) ⇒ Processor

Returns a new instance of Processor.



55
56
57
 
# File 'lib/pura/processing/processor.rb', line 55

def initialize(accumulator = nil)
  @accumulator = accumulator
end

Class Method Details

.accumulator(name, klass) ⇒ Object

Use for processor subclasses to specify the name and the class of their accumulator object (e.g. Pura::Image::Wrapper or any backend-specific image class).



39
40
41
42
43
 
# File 'lib/pura/processing/processor.rb', line 39

def self.accumulator(name, klass)
  define_method(name) { @accumulator }
  protected(name)
  const_set(:ACCUMULATOR_CLASS, klass)
end

.apply_operation(accumulator, name, args, block) ⇒ Object

Delegates to #apply_operation.



46
47
48
 
# File 'lib/pura/processing/processor.rb', line 46

def self.apply_operation(accumulator, (name, args, block))
  new(accumulator).apply_operation(name, *args, &block)
end

.call(source:, loader:, operations:, saver:, destination: nil) ⇒ Object 



11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
 
# File 'lib/pura/processing/processor.rb', line 11

def self.call(source:, loader:, operations:, saver:, destination: nil)
  unless source.is_a?(String) || source.is_a?(self::ACCUMULATOR_CLASS)
    fail Error, "invalid source: #{source.inspect}"
  end

  if operations.dig(0, 0).to_s.start_with?("resize_") &&
     loader.empty? &&
     supports_resize_on_load?

    accumulator = source
  else
    accumulator = load_image(source, **loader)
  end

  operations.each do |operation|
    accumulator = apply_operation(accumulator, operation)
  end

  if destination
    save_image(accumulator, destination, **saver)
  else
    accumulator
  end
end

.supports_resize_on_load? ⇒ Boolean

Whether the processor supports resizing the image upon loading.

Returns:

  • (Boolean) 


51
52
53
 
# File 'lib/pura/processing/processor.rb', line 51

def self.supports_resize_on_load?
  false
end

Instance Method Details

#apply_operation(name, *args, &block) ⇒ Object

Calls the operation to perform the processing. If the operation is defined on the processor (macro), calls the method. Otherwise calls the operation directly on the accumulator object. This provides a common umbrella above defined macros and direct operations.



63
64
65
66
67
68
69
70
71
72
 
# File 'lib/pura/processing/processor.rb', line 63

def apply_operation(name, *args, &block)
  receiver = respond_to?(name) ? self : @accumulator

  if args.last.is_a?(Hash)
    kwargs = args.pop
    receiver.public_send(name, *args, **kwargs, &block)
  else
    receiver.public_send(name, *args, &block)
  end
end

#custom(&block) ⇒ Object

Calls the given block with the accumulator object. Useful for when you want to access the accumulator object directly.



76
77
78
 
# File 'lib/pura/processing/processor.rb', line 76

def custom(&block)
  (block && block.call(@accumulator)) || @accumulator
end