我在
RAILS_ROOT/lib/paperclip_processors/watermark.rb
中添加了以下内容:
module Paperclip
class Watermark < Processor
attr_accessor :current_geometry, :target_geometry, :format, :whiny, :convert_options, :watermark_path, :overlay, :position
def initialize file, options = {}, attachment = nil
super
geometry = options[:geometry]
@file = file
@crop = geometry[-1,1] == '#'
@target_geometry = Geometry.parse geometry
@current_geometry = Geometry.from_file @file
@convert_options = options[:convert_options]
@whiny = options[:whiny].nil? ? true : options[:whiny]
@format = options[:format]
@watermark_path = options[:watermark_path]
@position = options[:position].nil? ? "SouthEast" : options[:position]
@overlay = options[:overlay].nil? ? true : false
@current_format = File.extname(@file.path)
@basename = File.basename(@file.path, @current_format)
end
def crop?
@crop
end
def convert_options?
not @convert_options.blank?
end
def make
dst = Tempfile.new([@basename, @format].compact.join("."))
dst.binmode
command = "convert"
params = [fromfile]
params += transformation_command
params << tofile(dst)
begin
success = Paperclip.run(command, params.flatten.compact.collect{|e| "'#{e}'"}.join(" "))
rescue PaperclipCommandLineError
raise PaperclipError, "There was an error resizing and cropping #{@basename}" if @whiny
end
if watermark_path
command = "composite"
params = %W[-gravity #{@position} #{watermark_path} #{tofile(dst)}]
params << tofile(dst)
begin
success = Paperclip.run(command, params.flatten.compact.collect{|e| "'#{e}'"}.join(" "))
rescue PaperclipCommandLineError
raise PaperclipError, "There was an error processing the watermark for #{@basename}" if @whiny
end
end
dst
end
def fromfile
File.expand_path(@file.path)
end
def tofile(destination)
File.expand_path(destination.path)
end
def transformation_command
scale, crop = @current_geometry.transformation_to(@target_geometry, crop?)
trans = %W[-resize #{scale}]
trans += %W[-crop #{crop} +repage] if crop
trans << convert_options if convert_options?
trans
end
end
end
更新: 如果您正在使用新版的Paperclip(3+),则开始块现在应该如下所示:
begin
Paperclip.run(command, params.join(' '))
rescue Cocaine::ExitStatusError => e
raise Paperclip::Error, "There was an error processing the watermark for #{@basename}" if @whiny
rescue Cocaine::CommandNotFoundError => e
raise Paperclip::Errors::CommandNotFoundError.new("Could not run the `convert` command. Please install ImageMagick.")
end
然后是 image_decorator.rb
模型:
require 'paperclip_processors/watermark'
Spree::Image.class_eval do
has_attached_file :attachment,
:processors => [:thumbnail, :watermark],
:styles => { :mini => '48x48>', :small => '100x100>', :product => '160x160#',
:large => {
:geometry => '460x680>',
:watermark_path => "#{Rails.root}/public/spree/watermark.png",
:position => 'SouthWest',
:format => :png
}
},
:default_style => :product,
:url => '/spree/products/:id/:style/:basename.:extension',
:path => ':rails_root/public/spree/products/:id/:style/:basename.:extension'
end