jquery_file_upload in Rails(ajax实现多张图片上传)

在此，我们要实现的是http://blueimp.github.com/jQuery-File-Upload/上传功能和效果。

1.准备工作

关键gem：carrierwave 和rmagick

在安装rmagick这个gem之前需要安装ImageMagick和相关库ImageMagick和ImageMagick-devel，直接yum install


下载关键js库函数和css

　　http://blueimp.github.com/jQuery-File-Upload/在这里有完全的下载，

jquery.iframe-transport.js

jquery.ui.widget.js

jquery.fileupload.js
jquery.fileupload-ip.js
jquery.fileupload-ui.js
locale.js

2.创建uploader

在Gemfile中添加

gem 'rmagick'



gem 'carrierwave'

bundle install

rails g uploader image

修改生成的image_uploader.rb

  include CarrierWave::RMagick



  # Create different versions of your uploaded files:

  version :thumb do

    process :resize_to_limit => [100, 100]

  end

修改这里是为了生成thumb图片。

3.生成picture的scaffold

rails g scaffold picture image:string

修改model

class Picture < ActiveRecord::Base

  attr_accessible :image

  include Rails.application.routes.url_helpers

  mount_uploader :image, AvatarUploader  #关联uploader



  #one convenient method to pass jq_upload the necessary information

  def to_jq_upload

    {

      "name" => read_attribute(:image),

      "size" =>image.size,

      "url" =>image.url,

      "thumbnail_url" =>image.thumb.url,

      "delete_url" => picture_path(:id => id),

      "delete_type" => "DELETE" 

    }

  end

end

修改controller

class PicturesController < ApplicationController



  def index

    @pictures = Picture.all

    render :json => @pictures.collect { |p| p.to_jq_upload }.to_json

  end

  def new

    

  end



  def create

    @picture = Picture.new(params[:picture])

    if @picture.save

      respond_to do |format|

        format.html {  

          render :json => [@picture.to_jq_upload].to_json, 

          :content_type => 'text/html',

          :layout => false

        }

        format.json {  

          render :json => [@picture.to_jq_upload].to_json           

        }

      end

    else 

      render :json => [{:error => "custom_failure"}], :status => 304

    end

  end



  def destroy

    @picture = Picture.find(params[:id])

    @picture.destroy

    render :json => true

  end

end

修改new.html.reb

<!-- Bootstrap CSS Toolkit styles -->

<link rel="stylesheet" href="http://blueimp.github.com/cdn/css/bootstrap.min.css">

<!-- Bootstrap styles for responsive website layout, supporting different screen sizes -->

<link rel="stylesheet" href="http://blueimp.github.com/cdn/css/bootstrap-responsive.min.css">

<!-- Bootstrap CSS fixes for IE6 -->

<!--[if lt IE 7]><link rel="stylesheet" href="http://blueimp.github.com/cdn/css/bootstrap-ie6.min.css"><![endif]-->



<!-- Bootstrap Image Gallery styles -->

<link rel="stylesheet" href="http://blueimp.github.com/Bootstrap-Image-Gallery/css/bootstrap-image-gallery.min.css">

<!-- Shim to make HTML5 elements usable in older Internet Explorer versions -->

<!--[if lt IE 9]><script src="http://html5shim.googlecode.com/svn/trunk/html5.js"></script><![endif]-->



<h2><%= t('photos.title') %></h2>

<%= form_for Picture.new, :html => { :multipart => true, :id => "fileupload"  } do |f| %>

        <!-- The fileupload-buttonbar contains buttons to add/delete files and start/cancel the upload -->

        <div class="row fileupload-buttonbar">

            <div class="span7">

                <!-- The fileinput-button span is used to style the file input field as button -->

                <span class="btn btn-success fileinput-button">

                    <i class="icon-plus icon-white"></i>

                    <span>Add files...</span>

                    <%= f.file_field :image %>

                </span>

                <button type="submit" class="btn btn-primary start">

                    <i class="icon-upload icon-white"></i>

                    <span>Start upload</span>

                </button>

                <button type="reset" class="btn btn-warning cancel">

                    <i class="icon-ban-circle icon-white"></i>

                    <span>Cancel upload</span>

                </button>

                <button type="button" class="btn btn-danger delete">

                    <i class="icon-trash icon-white"></i>

                    <span>Delete</span>

                </button>

                <input type="checkbox" class="toggle">

            </div>

            <div class="span5">

                <!-- The global progress bar -->

                <div class="progress progress-success progress-striped active fade">

                    <div class="bar" style="width:0%;"></div>

                </div>

            </div>

        </div>

        <!-- The loading indicator is shown during image processing -->

        <div class="fileupload-loading"></div>

        <br>

        <!-- The table listing the files available for upload/download -->

        <table class="table table-striped"><tbody class="files" data-toggle="modal-gallery" data-target="#modal-gallery"></tbody>

        </table>

    <% end %>

<script>

  var fileUploadErrors = {

    maxFileSize: 'File is too big',

    minFileSize: 'File is too small',

    acceptFileTypes: 'Filetype not allowed',

    maxNumberOfFiles: 'Max number of files exceeded',

    uploadedBytes: 'Uploaded bytes exceed file size',

    emptyResult: 'Empty file upload result'

  };

</script>



<!-- The template to display files available for upload -->

<script id="template-upload" type="text/x-tmpl">

{% for (var i=0, file; file=o.files[i]; i++) { %}

    <tr class="template-upload fade">

        <td class="preview"><span class="fade"></span></td>

        <td class="name"><span>{%=file.name%}</span></td>

        <td class="size"><span>{%=o.formatFileSize(file.size)%}</span></td>

        {% if (file.error) { %}

            <td class="error" colspan="2"><span class="label label-important">{%=locale.fileupload.error%}</span> {%=locale.fileupload.errors[file.error] || file.error%}</td>

        {% } else if (o.files.valid && !i) { %}

            <td>

                <div class="progress progress-success progress-striped active"><div class="bar" style="width:0%;"></div></div>

            </td>

            <td class="start">{% if (!o.options.autoUpload) { %}

                <button class="btn btn-primary">

                    <i class="icon-upload icon-white"></i>

                    <span>{%=locale.fileupload.start%}</span>

                </button>

            {% } %}</td>

        {% } else { %}

            <td colspan="2"></td>

        {% } %}

        <td class="cancel">{% if (!i) { %}

            <button class="btn btn-warning">

                <i class="icon-ban-circle icon-white"></i>

                <span>{%=locale.fileupload.cancel%}</span>

            </button>

        {% } %}</td>

    </tr>

{% } %}

</script>

<!-- The template to display files available for download -->

<script id="template-download" type="text/x-tmpl">

{% for (var i=0, file; file=o.files[i]; i++) { %}

    <tr class="template-download fade">

        {% if (file.error) { %}

            <td></td>

            <td class="name"><span>{%=file.name%}</span></td>

            <td class="size"><span>{%=o.formatFileSize(file.size)%}</span></td>

            <td class="error" colspan="2"><span class="label label-important">{%=locale.fileupload.error%}</span> {%=locale.fileupload.errors[file.error] || file.error%}</td>

        {% } else { %}

            <td class="preview">{% if (file.thumbnail_url) { %}

                <a href="{%=file.url%}" title="{%=file.name%}" rel="gallery" download="{%=file.name%}"><img src="{%=file.thumbnail_url%}"></a>

            {% } %}</td>

            <td class="name">

                <a href="{%=file.url%}" title="{%=file.name%}" rel="{%=file.thumbnail_url&&'gallery'%}" download="{%=file.name%}">{%=file.name%}</a>

            </td>

            <td class="size"><span>{%=o.formatFileSize(file.size)%}</span></td>

            <td colspan="2"></td>

        {% } %}

        <td class="delete">

            <button class="btn btn-danger" data-type="{%=file.delete_type%}" data-url="{%=file.delete_url%}">

                <i class="icon-trash icon-white"></i>

                <span>{%=locale.fileupload.destroy%}</span>

            </button>

            <input type="checkbox" name="delete" value="1">

        </td>

    </tr>

{% } %}

</script>







<!-- The jQuery UI widget factory, can be omited if jQuery UI is already included -->

<%= javascript_include_tag "jquery.ui.widget.js" %>

<!-- The Templates plugin is included to render the upload/download listings -->

<script src="http://blueimp.github.com/JavaScript-Templates/tmpl.min.js"></script>

<!-- The Load Image plugin is included for the preview images and image resizing functionality -->

<script src="http://blueimp.github.com/JavaScript-Load-Image/load-image.min.js"></script>

<!-- The Canvas to Blob plugin is included for image resizing functionality -->

<script src="http://blueimp.github.com/JavaScript-Canvas-to-Blob/canvas-to-blob.min.js"></script>

<!-- Bootstrap JS and Bootstrap Image Gallery are not required, but included for the demo -->

<script src="http://blueimp.github.com/cdn/js/bootstrap.min.js"></script>

<script src="http://blueimp.github.com/Bootstrap-Image-Gallery/js/bootstrap-image-gallery.min.js"></script>

<!-- The Iframe Transport is required for browsers without support for XHR file uploads -->

<%= javascript_include_tag "jquery.iframe-transport.js" %>

<!-- The basic File Upload plugin -->

<%= javascript_include_tag "jquery.fileupload.js" %>

<!-- The File Upload image processing plugin -->

<%= javascript_include_tag "jquery.fileupload-ip.js" %>

<!-- The File Upload user interface plugin -->

<%= javascript_include_tag "jquery.fileupload-ui.js" %>

<!-- The localization script -->

<%= javascript_include_tag "locale.js" %>





<!-- The XDomainRequest Transport is included for cross-domain file deletion for IE8+ -->

<!--[if gte IE 8]><%= javascript_include_tag "jquery.xdr-transport.js" %><![endif]-->





<script type="text/javascript" charset="utf-8">

    $(function () {

        // Initialize the jQuery File Upload widget:

        $('#fileupload').fileupload();

        // 

        // Load existing files:

        $.getJSON($('#fileupload').prop('action'), function (files) {

          var fu = $('#fileupload').data('fileupload'), 

            template;

          fu._adjustMaxNumberOfFiles(-files.length);

          template = fu._renderDownload(files)

            .appendTo($('#fileupload .files'));

          // Force reflow:

          fu._reflow = fu._transition && template.length &&

            template[0].offsetWidth;

          template.addClass('in');

          $('#loading').remove();

        });



    });

</script>