Blueimp Jquery File Upload : Doesn't show thum

I used Blueimp jQuery File Upload in my Rails application. When user select files, I want to show thumbnail of the image and the name of the image before uploading files to server.

I have been referring the demo to customize this plugin. I am able to print name of the file on the screen but not able to show thumbnail.

Here is the generated html

<!DOCTYPE html>
<html>
<head>
  <title>Fileupload</title>
  <link href="/assets/application.css?body=1" media="all" rel="stylesheet" type="text/css" />
<link href="/assets/jquery.fileupload-ui.css?body=1" media="all" rel="stylesheet" type="text/css" />
<script src="/assets/jquery.js?body=1" type="text/javascript"></script>
<script src="/assets/jquery_ujs.js?body=1" type="text/javascript"></script>
<script src="/assets/jquery.ui.widget.js?body=1" type="text/javascript"></script>
<script src="/assets/application.js?body=1" type="text/javascript"></script>
<script src="/assets/jquery.tmpl.js?body=1" type="text/javascript"></script>
<script src="/assets/load-image.min.js?body=1" type="text/javascript"></script>
<script src="/assets/canvas-to-blob.min.js?body=1" type="text/javascript"></script>
<script src="/assets/jquery.fileupload.js?body=1" type="text/javascript"></script>
<script src="/assets/jquery.fileupload-fp.js?body=1" type="text/javascript"></script>
<script src="/assets/jquery.fileupload-ui.js?body=1" type="text/javascript"></script>
<meta content="authenticity_token" name="csrf-param" />
<meta content="Akp8GLPQ+DlFYI1g3CUA71hk0vg3G84aVwcVRHTlRUY=" name="csrf-token" />
</head>
<body>
<div class="files">
  <form action="/users" class="upload" id="fileupload" method="post">
    <input id="user_photo" name="user[photo]" type="file" />
    <div>Upload files</div>
  </form>

  <table class="upload_files"></table>
</div>
<!-- The template to display files available for upload -->
<script id="template-upload" type="text/x-jquery-tmpl">
  <tr class="template-upload fade">
    <td class="preview"><span class="fade"></span></td>
    <td class="name"><span>${name}</span></td>
  </tr>
</script>
<script type="text/javascript" charset="utf-8">
    $(function () {
        $('#fileupload').fileupload({
            add: function (e, data) {
                console.log('add');
                $.each(data.files, function (index, file) {
                    console.log('Added file: ' + file.name);
                    //alert($('#tmpl-demo').tmpl(data));
                    $('#template-upload').tmpl(data.files).appendTo('.upload_files');
                });
                var jqXHR = data.submit()
                        .success(function (result, textStatus, jqXHR) {/* ... */})
                        .error(function (jqXHR, textStatus, errorThrown) {/* ... */})
                        .complete(function (result, textStatus, jqXHR) {
                            console.log("complete");
                            //$('.upload_files').append('<tr><td>'+ result +'</td></tr>');
                        });
            },
            progress: function (e, data) {
                console.log('progress');
            },
            start: function (e) {
                console.log('start');
            },
            done: function (e) {
                console.log('done');
            }
        }).bind('fileuploadadd', function (e, data) {
                    console.log('fileuploadadd');
                }).bind('fileuploadprogress', function (e, data) {
                    console.log('fileuploadprogress');
                }).bind('fileuploadstart', function (e) {
                    console.log('fileuploadstart');
                }).bind('fileuploaddone', function (e) {
                    console.log('fileuploaddone');
                });


    });
</script>
</body>
</html>

I compare the html generated after selecting files. The only difference is demo application has <canvas height="72" width="80"></canvas> element within <td class="preview"><span class="fade"></span></td> which is missing in my application.

It looks like some configuration problem. Would anyone please help me to configure it properly to show thumbnail as soon as user selects images from the disk?

回答1:

Those previews are not part of the basic version. They are part of the "additional plugin providing a complete user interface (jquery.fileupload-ui.js)."

So you have to include those js files, and you probably need some HTML wrappers.

Check out the source HTML of the demo, because it is included in that demo.

回答2:

Place this inside your add(e, data) callback function, adjusting for your own html elements accordingly:

$('body').append('<img src="' + URL.createObjectURL(data.files[0]) + '"/>');

The URL.createObjectURL function is documented here.

回答3:

Edit function _renderPreviews in file jquery.fileupload-ui.js

_renderPreviews: function (data) {           
        data.context.find('.preview').each(function (index, elm) {               
            $(elm).append(data.files[index].preview);
            $(elm).append('<img width="90" src="' + URL.createObjectURL(data.files[0]) + '"/>');
        });
    },