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Annotation of loncom/javascriptlib/file_upload.js, revision 1.2

1.1       musolffc    1: /* 
                      2: The LearningOnline Network with CAPA
                      3: JavaScript functions handling file uploading
                      4: 
1.2     ! raeburn     5: $Id: file_upload.js,v 1.1 2015/06/18 20:19:18 musolffc Exp $
1.1       musolffc    6: 
                      7: Copyright Michigan State University Board of Trustees
                      8: 
                      9: This file is part of the LearningOnline Network with CAPA (LON-CAPA).
                     10: 
                     11: LON-CAPA is free software; you can redistribute it and/or modify
                     12: it under the terms of the GNU General Public License as published by
                     13: the Free Software Foundation; either version 2 of the License, or
                     14: (at your option) any later version.
                     15: 
                     16: LON-CAPA is distributed in the hope that it will be useful,
                     17: but WITHOUT ANY WARRANTY; without even the implied warranty of
                     18: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                     19: GNU General Public License for more details.
                     20: 
                     21: You should have received a copy of the GNU General Public License
                     22: along with LON-CAPA; if not, write to the Free Software
                     23: Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
                     24: 
                     25: /home/httpd/html/adm/gpl.txt
                     26: 
                     27: http://www.lon-capa.org/
                     28: */
                     29: 
                     30: 
                     31: 
                     32: /*
                     33: This function accepts a file input element and a maximum upload size.  If the 
                     34: file(s) is too large, an alert is shown and the input is cleared.  It is better
                     35: to do this check on the client before uploading.
                     36: 
                     37: INPUT:
                     38:     fileInput -
1.2     ! raeburn    39:         <input type="file" class="LC_flUpload" />
        !            40:         Using the class "LC_flUpload" is needed to use the event handlers below.
1.1       musolffc   41:     maxSize -
                     42:         Maximum upload size in bytes.  It is usually calculated from quota and 
                     43:         disk usage.
                     44: */
                     45: function checkUploadSize (fileInput, maxSize) {
                     46:     try {
                     47:         var fileSize = 0;
                     48:         if ('files' in fileInput) {
                     49:             if (fileInput.files.length > 0) {
                     50:                 for (var i = 0; i < fileInput.files.length; i++) {
                     51:                     fileSize += fileInput.files[i].size;
                     52:                 }
                     53:                 if (fileSize > maxSize) {
                     54:                     alert("File(s) too large to be attached");
                     55:                     clearFileInput(fileInput);
                     56:                 }
                     57:             }
                     58:         } else { alert("no files in upFiles");}
                     59:     } catch (e) { alert("Error is: " + e); }
                     60: }
                     61: 
                     62: /* 
                     63: This function clears the contents of a file input element.
                     64: 
                     65: INPUT:
                     66:     ctrl -
                     67:         <input type="file" />
                     68: */
                     69: function clearFileInput(ctrl) {
                     70:     try {
                     71:         ctrl.value = null;
                     72:     } catch(ex) { }
                     73:     if (ctrl.value) {
                     74:         ctrl.parentNode.replaceChild(ctrl.cloneNode(true), ctrl);
                     75:     }
                     76: }
                     77: 
                     78: /*
                     79: This block adds event listeners to file upload elements.  It looks for input
1.2     ! raeburn    80: elements with class="LC_flUpload".
1.1       musolffc   81: 
1.2     ! raeburn    82:     <input type="file" class="LC_flUpload" />
1.1       musolffc   83: 
                     84: It also looks for a hidden element with id="free_space" that contains the maximum
                     85: upload size.
                     86: 
                     87:     <input type="hidden" id="free_space" value="$free_space" />
                     88: 
                     89: When the contents of the input element change, the function checkUploadSize()
                     90: checks if it is allowed based on size.
                     91: */
                     92: $( document ).ready(function() {
                     93:     var maxSize = $( "#free_space" ).val();
1.2     ! raeburn    94:     var upload_elements = $( ".LC_flUpload" );
1.1       musolffc   95:     for (var i=0; i<upload_elements.length; i++) {
                     96:         upload_elements[i].addEventListener( "change", function(){
                     97:             checkUploadSize(this, maxSize);
                     98:         });
                     99:     }
                    100: });