我(大致)遵循 RailsCasts教程#182,使用Paperclip,ImageMagick和Jcrop来允许上传的图像进行自定义裁剪。
由于我使用Amazon S3进行文件存储,因此我不得不重新调整教程的部分内容以适应。除了裁剪版本的图像未被重新处理(或该重新处理的结果未被重新上传到S3)之外,似乎一切都运行得很完美 - 因此,在裁剪过程之后,我仍然拥有最初上传的相同图像(对于我为每个图像存储的所有图像大小均如此)。
这是我的Feature(即Feature Image)模型:
我的FeaturesController的相关操作:
问题不在于自定义剪裁(偏移、剪裁区域等)出现错误,而是当我点击“剪裁”时没有任何剪裁发生 - 我只得到了从原始上传/处理中获得的图像。似乎根本没有发生“image.reprocess!”(或重新处理的结果没有保存到S3)。可能的原因是什么,我该怎么办?
由于我使用Amazon S3进行文件存储,因此我不得不重新调整教程的部分内容以适应。除了裁剪版本的图像未被重新处理(或该重新处理的结果未被重新上传到S3)之外,似乎一切都运行得很完美 - 因此,在裁剪过程之后,我仍然拥有最初上传的相同图像(对于我为每个图像存储的所有图像大小均如此)。
这是我的Feature(即Feature Image)模型:
class Feature < ActiveRecord::Base
require "#{Rails.root}/lib/paperclip_processors/cropper.rb"
attr_accessible :image_file_name, :image
attr_accessor :crop_x, :crop_y, :crop_w, :crop_h
after_update :reprocess_image, :if => :cropping?
if Rails.env == "production"
S3_CREDENTIALS = { :access_key_id => '<REDACTED>',
:secret_access_key => '<REDACTED>',
:bucket => "<REDACTED>"}
else
S3_CREDENTIALS = { :access_key_id => '<REDACTED>',
:secret_access_key => '<REDACTED>',
:bucket => "<REDACTED>"}
end
has_attached_file :image,
:styles => { :small => "240x135>", :croppable => "960x960>", :display => "960x540>" },
:processors => [:cropper],
:storage => :s3,
:s3_credentials => S3_CREDENTIALS,
:path => "features/:id/:style.:extension"
validates_attachment_content_type :image, :content_type => ['image/jpeg', 'image/gif', 'image/png',
'image/pjpeg', 'image/x-png'],
:message => 'must be a JPEG, GIF or PNG image'
def cropping?
!crop_x.blank? && !crop_y.blank? && !crop_w.blank? && !crop_h.blank?
end
def image_geometry(style = :original)
@geometry ||= {}
path = (image.options[:storage]==:s3) ? image.url(style) : image.path(style)
@geometry[style] ||= Paperclip::Geometry.from_file(path)
end
private
def reprocess_image
image.reprocess!
end
end
这是我的'cropper.rb'文件(Paperclip处理器):
module Paperclip
class Cropper < Thumbnail
def transformation_command
if crop_command
crop_command + super.sub(/ -crop \S+/, '')
else
super
end
end
def crop_command
target = @attachment.instance
if target.cropping?
" -crop '#{target.crop_w}x#{target.crop_h}+#{target.crop_x}+#{target.crop_y}'"
end
end
end
end
我的FeaturesController的相关操作:
class FeaturesController < ApplicationController
def new
@feature = Feature.new
end
def create
@feature = Feature.new(params[:feature])
if @feature.save
if params[:feature][:image].blank?
flash[:notice] = "New feature added!"
redirect_to @feature
else
render :crop
end
else
@title = "Add a New Feature"
render :new
end
end
def edit
@feature = Feature.find(params[:id])
@title = "Edit #{@feature.headline}"
end
def update
@feature = Feature.find(params[:id])
if @feature.update_attributes(params[:feature])
if params[:feature][:image].blank?
flash[:notice] = "Feature updated!"
redirect_to @feature
else
render :crop
end
else
@title = "Edit Feature"
render :edit
end
end
end
我 'crop.html.erb' 视图文件中相关的代码行:
<% content_for :javascript_includes do %>
<%= javascript_include_tag 'jquery.Jcrop.min' %>
<script type="text/javascript" charset="utf-8">
$(function() {
$('#cropbox').Jcrop({
onChange: update_crop,
onSelect: update_crop,
setSelect: [0, 0, 960, 540],
aspectRatio: 960/540
});
});
function update_crop(coords) {
var ratio = <%= @feature.image_geometry(:original).width %> / <%= @feature.image_geometry(:croppable).width %>;
$("#crop_x").val(Math.round(coords.x * ratio));
$("#crop_y").val(Math.round(coords.y * ratio));
$("#crop_w").val(Math.round(coords.w * ratio));
$("#crop_h").val(Math.round(coords.h * ratio));
};
</script>
<% end %>
<% content_for :style_includes do %>
<%= stylesheet_link_tag 'jquery.Jcrop', :media => 'screen' %>
<% end %>
<%= image_tag @feature.image.url(:croppable), :id => "cropbox" %>
<% form_for @feature do |f| %>
<% for attribute in [:crop_x, :crop_y, :crop_w, :crop_h] %>
<%= f.hidden_field attribute, :id => attribute %>
<% end %>
<p><%= f.submit "Crop" %></p>
<% end %>
问题不在于自定义剪裁(偏移、剪裁区域等)出现错误,而是当我点击“剪裁”时没有任何剪裁发生 - 我只得到了从原始上传/处理中获得的图像。似乎根本没有发生“image.reprocess!”(或重新处理的结果没有保存到S3)。可能的原因是什么,我该怎么办?