resources/mediawiki.special/mediawiki.special.upload.js

   1 /*
   2  * JavaScript for Special:Upload
   3  * Note that additional code still lives in skins/common/upload.js
   4  */
   5
   6 $(function() {
   7         /**
   8          * Is the FileAPI available with sufficient functionality?
   9          */
  10         function hasFileAPI() {
  11                 return (typeof window.FileReader != "undefined");
  12         }
  13
  14         /**
  15          * Check if this is a recognizable image type...
  16          * Also excludes files over 10M to avoid going insane on memory usage.
  17          *
  18          * @todo is there a way we can ask the browser what's supported in <img>s?
  19          *
  20          * @param {File} file
  21          * @return boolean
  22          */
  23         function fileIsPreviewable(file) {
  24                 var known = ['image/png', 'image/gif', 'image/jpeg', 'image/svg+xml'];
  25                 var tooHuge = 10 * 1024 * 1024;
  26                 return ($.inArray(file.type, known) != -1) && (file.size > 0) && (file.size < tooHuge);
  27         }
  28
  29         /**
  30          * Show a thumbnail preview of PNG, JPEG, GIF, and SVG files prior to upload
  31          * in browsers supporting HTML5 FileAPI.
  32          *
  33          * As of this writing, known good:
  34          * - Firefox 3.6+
  35          * - Chrome 7.something
  36          *
  37          * @todo check file size limits and warn of likely failures
  38          *
  39          * @param {File} file
  40          */
  41         function showPreview(file) {
  42                 var thumb = $("<div id='mw-upload-thumbnail' class='thumb tright'>" +
  43                                             "<div class='thumbinner'>" +
  44                                               "<img style='max-width: 180px; max-height: 180px' />" +
  45                                               "<div class='thumbcaption'><div class='filename'></div><div class='fileinfo'></div></div>" +
  46                                             "</div>" +
  47                                           "</div>");
  48                 thumb.find('.filename').text(file.name).end()
  49                      .find('.fileinfo').text(prettySize(file.size)).end()
  50                      .find('img').attr('src', wgScriptPath + '/skins/common/images/spinner.gif');
  51                 $('#mw-htmlform-source').parent().prepend(thumb);
  52
  53                 fetchPreview(file, function(dataURL) {
  54                         var img = $('#mw-upload-thumbnail img');
  55                         img.load(function() {
  56                                 if ('naturalWidth' in img[0]) {
  57                                         var w = img[0].naturalWidth, h = img[0].naturalHeight;
  58                                         var info = mediaWiki.msg('widthheight', w, h) +
  59                                                 ', ' + prettySize(file.size);
  60                                         $('#mw-upload-thumbnail .fileinfo').text(info);
  61                                 }
  62                         });
  63                         img.attr('src', dataURL);
  64                 });
  65         }
  66
  67         /**
  68          * Start loading a file into memory; when complete, pass it as a
  69          * data URL to the callback function.
  70          *
  71          * @param {File} file
  72          * @param {function} callback
  73          */
  74         function fetchPreview(file, callback) {
  75                 var reader = new FileReader();
  76                 reader.onload = function() {
  77                         callback(reader.result);
  78                 };
  79                 reader.readAsDataURL(file);
  80         }
  81
  82         /**
  83          * Format a file size attractively.
  84          * @todo match numeric formatting
  85          *
  86          * @param {number} s
  87          * @return string
  88          */
  89         function prettySize(s) {
  90                 var sizes = ['size-bytes', 'size-kilobytes', 'size-megabytes', 'size-gigabytes'];
  91                 while (s >= 1024 && sizes.length > 1) {
  92                         s /= 1024;
  93                         sizes = sizes.slice(1);
  94                 }
  95                 return mediaWiki.msg(sizes[0], Math.round(s))
  96         }
  97
  98         /**
  99          * Clear the file upload preview area.
 100          */
 101         function clearPreview() {
 102                 $('#mw-upload-thumbnail').remove();
 103         }
 104
 105         if (hasFileAPI()) {
 106                 // Update thumbnail when the file selection control is updated.
 107                 $('#wpUploadFile').change(function() {
 108                         clearPreview();
 109                         if (this.files && this.files.length) {
 110                                 // Note: would need to be updated to handle multiple files.
 111                                 var file = this.files[0];
 112                                 if (fileIsPreviewable(file)) {
 113                                         showPreview(file);
 114                                 }
 115                         }
 116                 });
 117         }
 118 });