Add `ellipsis` data rendering helper to the plug-ins.

This is a new category of plug-ins - they are functions that use the
orthogonal data options of DataTables 1.10 to provide formatting helper
functions. They do not directly interface with DataTables themselves,
but provide easy to use functions for developers to format their data in
the DataTable.

dataRender/ellipsis.js

@@ -0,0 +1,77 @@
+/**
+ * This data rendering helper method can be useful for cases where you have
+ * potentially large data strings to be shown in a column that is restricted by
+ * width. The data for the column is still fully searchable and sortable, but if
+ * it is longer than a give number of characters, it will be truncated and
+ * shown with ellipsis. A browser provided tooltip will show the full string
+ * to the end user on mouse hover of the cell.
+ *
+ * This function should be used with the `dt-init columns.render` configuration
+ * option of DataTables.
+ *
+ * It accepts two parameters:
+ *
+ * 1. `-type integer` - The number of characters to restrict the displayed data
+ *    to.
+ * 2. `-type boolean` (optional - default `false`) - Indicate if the truncation
+ *    of the string should not occur in the middle of a word (`true`) or if it
+ *    can (`false`). This can allow the display of strings to look nicer, at the
+ *    expense of showing less characters.
+ *
+ *  @name ellipsis
+ *  @summary Restrict output data to a particular length, showing anything
+ *      longer with ellipsis and a browser provided tooltip on hover.
+ *  @author [Allan Jardine](http://datatables.net)
+ *  @requires DataTables 1.10+
+ *
+ * @returns {Number} Calculated average
+ *
+ *  @example
+ *    // Restrict a column to 17 characters, don't split words
+ *    $('#example').DataTable( {
+ *      columnDefs: [ {
+ *        targets: 1,
+ *        render: $.fn.dataTable.render.ellipsis( 17, true )
+ *      } ]
+ *    } );
+ *
+ *  @example
+ *    // Restrict a column to 10 characters, do split words
+ *    $('#example').DataTable( {
+ *      columnDefs: [ {
+ *        targets: 2,
+ *        render: $.fn.dataTable.render.ellipsis( 10 )
+ *      } ]
+ *    } );
+ */
+
+jQuery.fn.dataTable.render = {
+	ellipsis: function ( cutoff, wordbreak ) {
+		return {
+			display: function ( d ) {
+				if ( wordbreak === undefined ) {
+					wordbreak = false;
+				}
+
+				if ( typeof d !== 'number' && typeof d !== 'string' ) {
+					return d;
+				}
+
+				var str = d.toString(); // cast numbers
+
+				if ( d.length < cutoff ) {
+					return d;
+				}
+
+				str = d.substr(0, cutoff);
+
+				if ( wordbreak ) {
+					// Find the last white space character in the string
+					str = str.replace(/\s([^\s]*)$/, '');
+				}
+
+				return '<span class="ellipsis" title="'+d+'">'+str+'&#8230;</span>';
+			}
+		};
+	}
+};