Module: ImageProcessing::Chainable

Included in:
Builder, MiniMagick, Vips
Defined in:
lib/image_processing/chainable.rb

Overview

Implements a chainable interface for building processing options.

Constant Summary collapse

DEFAULT_OPTIONS =

Empty options which the builder starts with.

{
  source:     nil,
  loader:     {},
  saver:      {},
  format:     nil,
  operations: [],
  processor:  nil,
}.freeze

Instance Method Summary collapse

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

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

Assume that any unknown method names an operation supported by the processor. Add a bang (“!”) if you want processing to be performed.



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# File 'lib/image_processing/chainable.rb', line 45

def method_missing(name, *args, &block)
  return super if name.to_s.end_with?("?")
  return send(name.to_s.chomp("!"), *args, &block).call if name.to_s.end_with?("!")

  operation(name, *args, &block)
end

Instance Method Details

#apply(operations) ⇒ Object

Add multiple operations as a hash or an array.

.apply(resize_to_limit: [400, 400], strip: true)
# or
.apply([[:resize_to_limit, [400, 400]], [:strip, true])



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# File 'lib/image_processing/chainable.rb', line 29

def apply(operations)
  operations.inject(self) do |builder, (name, argument)|
    if argument == true || argument == nil
      builder.send(name)
    elsif argument.is_a?(Array)
      builder.send(name, *argument)
    elsif argument.is_a?(Hash)
      builder.send(name, **argument)
    else
      builder.send(name, argument)
    end
  end
end

#branch(loader: nil, saver: nil, operations: nil, **other_options) ⇒ Object

Creates a new builder object, merging current options with new options.



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# File 'lib/image_processing/chainable.rb', line 69

def branch(loader: nil, saver: nil, operations: nil, **other_options)
  options = respond_to?(:options) ? self.options : DEFAULT_OPTIONS

  options = options.merge(loader: options[:loader].merge(loader)) if loader
  options = options.merge(saver: options[:saver].merge(saver)) if saver
  options = options.merge(operations: options[:operations] + operations) if operations
  options = options.merge(processor: self::Processor) unless self.is_a?(Builder)
  options = options.merge(other_options)

  options.freeze

  Builder.new(options)
end

#call(file = nil, destination: nil, **call_options) ⇒ Object

Call the defined processing and get the result. Allows specifying the source file and destination.



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# File 'lib/image_processing/chainable.rb', line 60

def call(file = nil, destination: nil, **call_options)
  options = {}
  options = options.merge(source: file) if file
  options = options.merge(destination: destination) if destination

  branch(**options).call!(**call_options)
end

#convert(format) ⇒ Object

Specify the output format.



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# File 'lib/image_processing/chainable.rb', line 10

def convert(format)
  branch format: format
end

#loader(**options) ⇒ Object

Specify processor options applied when loading the image.



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# File 'lib/image_processing/chainable.rb', line 15

def loader(**options)
  branch loader: options
end

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

Add an operation defined by the processor.



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# File 'lib/image_processing/chainable.rb', line 54

def operation(name, *args, &block)
  branch operations: [[name, args, *block]]
end

#saver(**options) ⇒ Object

Specify processor options applied when saving the image.



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# File 'lib/image_processing/chainable.rb', line 20

def saver(**options)
  branch saver: options
end

#source(file) ⇒ Object

Specify the source image file.



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# File 'lib/image_processing/chainable.rb', line 5

def source(file)
  branch source: file
end