MDL-57972 javascript: Add truncate.js third party lib

Part of MDL-55611

lib/amd/src/truncate.js

@@ -0,0 +1,125 @@
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Module for text truncation.
+ *
+ * Implementation provided by Pathable (thanks!).
+ * See: https://github.com/pathable/truncate
+ *
+ * @module     core/truncate
+ * @package    core
+ * @class      truncate
+ * @copyright  2017 Pathable
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+define(['jquery'], function($) {
+
+  // Matches trailing non-space characters.
+  var chop = /(\s*\S+|\s)$/;
+
+  // Matches the first word in the string.
+  var start = /^(\S*)/;
+
+  // Return a truncated html string.  Delegates to $.fn.truncate.
+  $.truncate = function(html, options) {
+    return $('<div></div>').append(html).truncate(options).html();
+  };
+
+  // Truncate the contents of an element in place.
+  $.fn.truncate = function(options) {
+    if ($.isNumeric(options)) options = {length: options};
+    var o = $.extend({}, $.truncate.defaults, options);
+
+    return this.each(function() {
+      var self = $(this);
+
+      if (o.noBreaks) self.find('br').replaceWith(' ');
+
+      var text = self.text();
+      var excess = text.length - o.length;
+
+      if (o.stripTags) self.text(text);
+
+      // Chop off any partial words if appropriate.
+      if (o.words && excess > 0) {
+        var truncated = text.slice(0, o.length).replace(chop, '').length;
+
+        if (o.keepFirstWord && truncated === 0) {
+          excess = text.length - start.exec(text)[0].length - 1;
+        } else {
+          excess = text.length - truncated - 1;
+        }
+      }
+
+      if (excess < 0 || !excess && !o.truncated) return;
+
+      // Iterate over each child node in reverse, removing excess text.
+      $.each(self.contents().get().reverse(), function(i, el) {
+        var $el = $(el);
+        var text = $el.text();
+        var length = text.length;
+
+        // If the text is longer than the excess, remove the node and continue.
+        if (length <= excess) {
+          o.truncated = true;
+          excess -= length;
+          $el.remove();
+          return;
+        }
+
+        // Remove the excess text and append the ellipsis.
+        if (el.nodeType === 3) {
+          $(el.splitText(length - excess - 1)).replaceWith(o.ellipsis);
+          return false;
+        }
+
+        // Recursively truncate child nodes.
+        $el.truncate($.extend(o, {length: length - excess}));
+        return false;
+      });
+    });
+  };
+
+  $.truncate.defaults = {
+
+    // Strip all html elements, leaving only plain text.
+    stripTags: false,
+
+    // Only truncate at word boundaries.
+    words: false,
+
+    // When 'words' is active, keeps the first word in the string
+    // even if it's longer than a target length.
+    keepFirstWord: false,
+
+    // Replace instances of <br> with a single space.
+    noBreaks: false,
+
+    // The maximum length of the truncated html.
+    length: Infinity,
+
+    // The character to use as the ellipsis.  The word joiner (U+2060) can be
+    // used to prevent a hanging ellipsis, but displays incorrectly in Chrome
+    // on Windows 7.
+    // http://code.google.com/p/chromium/issues/detail?id=68323
+    ellipsis: '\u2026' // '\u2060\u2026'
+
+  };
+
+    return {
+        truncate: $.truncate,
+    };
+});