1: /*
2: The LearningOnline Network with CAPA
3: JavaScript functions handling file uploading
4:
5: $Id: file_upload.js,v 1.3 2019/08/11 14:16:55 raeburn Exp $
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 the universal part of the id
34: used for the hidden input element containing maximum upload size permitted.
35: If the file(s) is too large, an alert is shown and the input is cleared.
36:
37: INPUT:
38: fileInput -
39: <input type="file" class="LC_flUpload" />
40: Using the class "LC_flUpload" is needed to use the event handlers below.
41: sizeItem -
42: <input type="hidden" id="PREFIXsizeItemSUFFIX" value="$maxsize" />
43:
44: The PREFIX is empty unless the resource is within a composite page.
45:
46: The SUFFIX is empty in cases where there will only ever be one file upload
47: input element in a web page. Otherwise it will contain a unique identifier,
48: so different maximum sizes can exist for each upload element.
49:
50: The value assigned to the hidden element is the maximum upload size in bytes.
51:
52: It is either calculated from quota and disk usage (e.g., upload to a course,
53: authoring space or portfolio space), or is set by a parameter (e.g., upload
54: to a dropbox, essayresponse or externalresponse item), or is hard-coded
55: (e.g., upload to the help request form, or an attachment to a discussion post
56: or feedback message).
57:
58: */
59:
60: function checkUploadSize (fileInput,sizeItem) {
61: try {
62: var maxSize = getMaxSize(fileInput,sizeItem);
63: var fileSize = 0;
64: if ('files' in fileInput) {
65: if (fileInput.files.length > 0) {
66: for (var i = 0; i < fileInput.files.length; i++) {
67: fileSize += fileInput.files[i].size;
68: }
69: if (fileSize > maxSize) {
70: alert("File(s) too large to be attached");
71: clearFileInput(fileInput);
72: }
73: }
74: } else { alert("no files selected for upload");}
75: } catch (e) { alert("Error is: " + e); }
76: }
77:
78: /*
79: This function clears the contents of a file input element.
80:
81: INPUT:
82: ctrl -
83: <input type="file" />
84: */
85: function clearFileInput(ctrl) {
86: try {
87: ctrl.value = null;
88: } catch(e) { }
89: if (ctrl.value) {
90: ctrl.parentNode.replaceChild(ctrl.cloneNode(true), ctrl);
91: }
92: }
93:
94: /*
95: This function retrieves the allowed maximum file size for a file input element
96: INPUT:
97: fileInput -
98: <input type="file" />
99: sizeItem -
100: <input type="hidden" id="PREFIXsizeItemSUFFIX" />
101:
102: For upload to a dropbox, essayresponse or externalresponse item,
103: the PREFIX and SUFFIX are extracted from the id of the file upload
104: element, by separating the id into parts before and after HWFILE.
105:
106: The PREFIX is empty unless the resource is within a composite page.
107:
108: */
109: function getMaxSize (fileInput,sizeItem) {
110: var maxSize = 0;
111: var sizeId = sizeItem;
112: var uploadId;
113: try {
114: if ($(fileInput).hasClass("LC_hwkfile")) {
115: uploadId = $(fileInput).attr('id');
116: var re = /^(|\w*)HWFILE(.+)$/;
117: var found = uploadId.match(re);
118: if (found.length == 3) {
119: sizeId = found[1]+sizeItem+'_'+found[2];
120: }
121: }
122: if ( $("#"+sizeId).length) {
123: if ( $("#"+sizeId).val() > 0) {
124: maxSize = $("#"+sizeId).val();
125: }
126: }
127: }
128: catch(e) { }
129: return maxSize;
130: }
131:
132: /*
133: This block adds event listeners to file upload elements. It looks for input
134: elements with class="LC_flUpload".
135:
136: <input type="file" class="LC_flUpload" />
137:
138: It also looks for a hidden element with an id containing: "LC_free_space",
139: which contains the maximum allowable upload size (bytes).
140:
141: <input type="hidden" id="*LC_free_space*" value="$free_space" />
142:
143: The * before LC_free_space and the * after LC_free_space are PREFIX and SUFFIX.
144:
145: When the contents of the input element change, the function checkUploadSize()
146: checks if it is allowed based on size.
147: */
148: $( document ).ready(function() {
149: var upload_elements = $( ".LC_flUpload" );
150: for (var i=0; i<upload_elements.length; i++) {
151: if (getMaxSize(upload_elements[i],'LC_free_space')) {
152: upload_elements[i].addEventListener( "change", function(){
153: checkUploadSize(this,'LC_free_space');
154: });
155: }
156: }
157: });
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