class MiniMagick::Tool

Abstract class that wraps command-line tools. It shouldn't be used directly, but through one of its subclasses (e.g. {MiniMagick::Tool::Mogrify}). Use this class if you want to be closer to the metal and execute ImageMagick commands directly, but still with a nice Ruby interface.

@example

MiniMagick::Tool::Mogrify.new do |builder|
  builder.resize "500x500"
  builder << "path/to/image.jpg"
end

Constants

CREATION_OPERATORS

Attributes

args[R]

@private

name[R]

@private

Public Class Methods

new(*args) { |instance| ... } click to toggle source

Aside from classic instantiation, it also accepts a block, and then executes the command in the end.

@example

version = MiniMagick::Tool::Identify.new { |b| b.version }
puts version

@return [MiniMagick::Tool, String] If no block is given, returns an

instance of the tool, if block is given, returns the output of the
command.
Calls superclass method
# File lib/mini_magick/tool.rb, line 35
def self.new(*args)
  instance = super(*args)

  if block_given?
    yield instance
    instance.call
  else
    instance
  end
end
new(name, options = {}) click to toggle source

@param whiny [Boolean] Whether to raise errors on exit codes different

than 0

@example

MiniMagick::Tool::Identify.new(whiny: false) do |identify|
  identify.help # returns exit status 1, which would otherwise throw an error
end
# File lib/mini_magick/tool.rb, line 55
def initialize(name, options = {})
  warn "MiniMagick::Tool.new(false) is deprecated and will be removed in MiniMagick 5, use MiniMagick::Tool.new(whiny: false) instead." if !options.is_a?(Hash)

  @name  = name
  @args  = []
  @whiny = options.is_a?(Hash) ? options.fetch(:whiny, MiniMagick.whiny) : options
end
option_methods() click to toggle source
# File lib/mini_magick/tool.rb, line 261
def self.option_methods
  @option_methods ||= (
    tool = new(whiny: false)
    tool << "-help"
    help_page = tool.call(stderr: false)

    cli_options = help_page.scan(/^\s+-[a-z\-]+/).map(&:strip)
    if tool.name == "mogrify" && MiniMagick.graphicsmagick?
      # These options were undocumented before 2015-06-14 (see gm bug 302)
      cli_options |= %w[-box -convolve -gravity -linewidth -mattecolor -render -shave]
    end

    cli_options.map { |o| o[1..-1].tr('-','_') }
  )
end

Public Instance Methods

+(*values) click to toggle source

Changes the last operator to its “plus” form.

@example

MiniMagick::Tool::Mogrify.new do |mogrify|
  mogrify.antialias.+
  mogrify.distort.+("Perspective", "0,0,4,5 89,0,45,46")
end
# executes `mogrify +antialias +distort Perspective '0,0,4,5 89,0,45,46'`

@return [self]

# File lib/mini_magick/tool.rb, line 163
def +(*values)
  args[-1] = args[-1].sub(/^-/, '+')
  self.merge!(values)
  self
end
<<(arg) click to toggle source

Appends raw options, useful for appending image paths.

@return [self]

# File lib/mini_magick/tool.rb, line 136
def <<(arg)
  args << arg.to_s
  self
end
call(*args) { |stdout, stderr, status| ... } click to toggle source

Executes the command that has been built up.

@example

mogrify = MiniMagick::Tool::Mogrify.new
mogrify.resize("500x500")
mogrify << "path/to/image.jpg"
mogrify.call # executes `mogrify -resize 500x500 path/to/image.jpg`

@example

mogrify = MiniMagick::Tool::Mogrify.new
# build the command
mogrify.call do |stdout, stderr, status|
  # ...
end

@yield [Array] Optionally yields stdout, stderr, and exit status

@return [String] Returns the output of the command

# File lib/mini_magick/tool.rb, line 83
def call(*args)
  options = args[-1].is_a?(Hash) ? args.pop : {}
  warn "Passing whiny to MiniMagick::Tool#call is deprecated and will be removed in MiniMagick 5, use MiniMagick::Tool.new(whiny: false) instead." if args.any?
  whiny = args.fetch(0, @whiny)

  options[:whiny] = whiny
  options[:stderr] = false if block_given?

  shell = MiniMagick::Shell.new
  stdout, stderr, status = shell.run(command, options)
  yield stdout, stderr, status if block_given?

  stdout.chomp("\n")
end
clone(*args) click to toggle source

This option is a valid ImageMagick option, but it's also a Ruby method, so we need to override it so that it correctly acts as an option method.

# File lib/mini_magick/tool.rb, line 236
def clone(*args)
  self << '-clone'
  self.merge!(args)
  self
end
command() click to toggle source

The currently built-up command.

@return [Array<String>]

@example

mogrify = MiniMagick::Tool::Mogrify.new
mogrify.resize "500x500"
mogrify.contrast
mogrify.command #=> ["mogrify", "-resize", "500x500", "-contrast"]
# File lib/mini_magick/tool.rb, line 109
def command
  [*executable, *args]
end
executable() click to toggle source

The executable used for this tool. Respects {MiniMagick::Configuration#cli} and {MiniMagick::Configuration#cli_path}.

@return [Array<String>]

@example

MiniMagick.configure { |config| config.cli = :graphicsmagick }
identify = MiniMagick::Tool::Identify.new
identify.executable #=> ["gm", "identify"]
# File lib/mini_magick/tool.rb, line 124
def executable
  exe = [name]
  exe.unshift "gm" if MiniMagick.graphicsmagick?
  exe.unshift File.join(MiniMagick.cli_path, exe.shift) if MiniMagick.cli_path
  exe
end
merge!(new_args) click to toggle source

Merges a list of raw options.

@return [self]

# File lib/mini_magick/tool.rb, line 146
def merge!(new_args)
  new_args.each { |arg| self << arg }
  self
end
method_missing(name, *args) click to toggle source

Any undefined method will be transformed into a CLI option

mogrify = MiniMagick::Tool.new("mogrify")
mogrify.adaptive_blur("...")
mogrify.foo_bar
mogrify.command.join(" ") "mogrify -adaptive-blur ... -foo-bar"
# File lib/mini_magick/tool.rb, line 250
def method_missing(name, *args)
  option = "-#{name.to_s.tr('_', '-')}"
  self << option
  self.merge!(args)
  self
end
respond_to_missing?(method_name, include_private = false) click to toggle source
# File lib/mini_magick/tool.rb, line 257
def respond_to_missing?(method_name, include_private = false)
  true
end
stack() { |self| ... } click to toggle source

Create an ImageMagick stack in the command (surround.

@example

MiniMagick::Tool::Convert.new do |convert|
  convert << "wand.gif"
  convert.stack do |stack|
    stack << "wand.gif"
    stack.rotate(30)
  end
  convert.append.+
  convert << "images.gif"
end
# executes `convert wand.gif \( wizard.gif -rotate 30 \) +append images.gif`
# File lib/mini_magick/tool.rb, line 184
def stack
  self << "("
  yield self
  self << ")"
end
stdin() click to toggle source

Adds ImageMagick's pseudo-filename `-` for standard input.

@example

identify = MiniMagick::Tool::Identify.new
identify.stdin
identify.call(stdin: image_content)
# executes `identify -` with the given standard input
# File lib/mini_magick/tool.rb, line 199
def stdin
  self << "-"
end
stdout() click to toggle source

Adds ImageMagick's pseudo-filename `-` for standard output.

@example

content = MiniMagick::Tool::Convert.new do |convert|
  convert << "input.jpg"
  convert.auto_orient
  convert.stdout
end
# executes `convert input.jpg -auto-orient -` which returns file contents
# File lib/mini_magick/tool.rb, line 214
def stdout
  self << "-"
end