Add filter_hideEmpty; Correct pager & widget updating. Fixes #450.

When all rows are removed from the table, ensure widgets are applied
(including refreshing the filter search), and ensure the pager display
updates. Add filter_hideEmpty option to allow setting hiding the filter
row when the table doesn't contain any tbody rows.

addons/pager/jquery.tablesorter.pager.js

@@ -116,8 +116,8 @@
 			d = p.cssDisabled,
 			dis = !!disable,
 			first = ( dis || p.page === 0 ),
-			last = ( dis || p.page === tp - 1 || p.totalPages === 0 ),
-			tp = Math.min( p.totalPages, p.filteredPages );
+			tp = Math.min( p.totalPages, p.filteredPages ),
+			last = ( dis || (p.page === tp - 1) || p.totalPages === 0 );
 			if ( p.updateArrows ) {
 				p.$container.find(p.cssFirst + ',' + p.cssPrev)[ first ? a : r ](d).attr('aria-disabled', first);
 				p.$container.find(p.cssNext + ',' + p.cssLast)[ last ? a : r ](d).attr('aria-disabled', last);
@@ -603,6 +603,8 @@
 				p.size = $.data(table, 'pagerLastSize') || p.size || 10;
 				p.totalPages = Math.ceil( p.totalRows / p.size );
 				renderTable(table, rows, p);
+				// update display here in case all rows are removed
+				updatePageDisplay(table, p, false);
 			}
 		};
 

docs/index.html

@@ -1508,6 +1508,8 @@ $(function(){
       filter_formatter     : null,
       // add custom filter functions using this option.
       filter_functions     : null,
+      // hide filter row when table is empty
+      filter_hideEmpty     : true,
       // if true, the filter row is hidden initially until hovered/focused.
       filter_hideFilters   : false,
       // if true, make all searches case-insensitive.
@@ -2083,6 +2085,29 @@ $(function(){
 				<td><a href="example-widget-filter-custom.html">Example</a></td>
 			</tr>
 
+     : true,  // hide filter row when table is empty
+
+			<tr id="widget-filter-hideempty">
+				<td><a href="#" class="permalink">filter_hideEmpty</a></td>
+				<td>Boolean</td>
+				<td>true</td>
+				<td>
+					Filter widget: Set this option to <code>false</code> to always show the filter row; by default, the filter row is completely hidden when no rows exist within the tbody (<span class="version">v2.15</span>).
+					<div class="collapsible">
+					<br>
+					Use the <a href="#widget-filter-hideempty"><code>filter_hideEmpty</code></a> option as follows:
+					<pre class="prettyprint lang-js">$(function(){
+  $("table").tablesorter({
+    widgets: ["filter"],
+    widgetOptions : {
+      filter_hideEmpty : false
+    }
+  });
+});</pre></div>
+				</td>
+				<td></td>
+			</tr>
+
 			<tr id="widget-filter-hidefilters">
 				<td><a href="#" class="permalink">filter_hideFilters</a></td>
 				<td>Boolean</td>

js/jquery.tablesorter.js

@@ -327,7 +327,11 @@
 					c2 = c.cache,
 					r, n, totalRows, checkCell, $bk, $tb,
 					i, j, k, l, pos, appendTime;
-				if (isEmptyObject(c2)) { return; } // empty table - fixes #206/#346
+				// empty table - fixes #206/#346
+				if (isEmptyObject(c2)) {
+					// run pager appender in case the table was just emptied
+					return c.appender ? c.appender(table, rows) : '';
+				}
 				if (c.debug) {
 					appendTime = new Date();
 				}

js/jquery.tablesorter.widgets.js

@@ -355,6 +355,7 @@ ts.addWidget({
 		filter_filteredRow   : 'filtered', // class added to filtered rows; needed by pager plugin
 		filter_formatter     : null,  // add custom filter elements to the filter row
 		filter_functions     : null,  // add custom filter functions using this option
+		filter_hideEmpty     : true,  // hide filter row when table is empty
 		filter_hideFilters   : false, // collapse filter row when mouse leaves the area
 		filter_ignoreCase    : true,  // if true, make all searches case-insensitive
 		filter_liveSearch    : true,  // if true, search column content while the user types (with a delay)
@@ -369,9 +370,7 @@ ts.addWidget({
 	},
 	format: function(table, c, wo) {
 		if (!c.$table.hasClass('hasFilters')) {
-			if (c.parsers || !c.parsers && wo.filter_serversideFiltering) {
-				ts.filter.init(table, c, wo);
-			}
+			ts.filter.init(table, c, wo);
 		}
 	},
 	remove: function(table, c, wo) {
@@ -560,7 +559,8 @@ ts.filter = {
 		}
 
 		c.$table.bind('addRows updateCell update updateRows updateComplete appendCache filterReset filterEnd search '.split(' ').join('.tsfilter '), function(event, filter) {
-			if ( !/(search|filterReset|filterEnd)/.test(event.type) ) {
+			c.$table.find('.' + ts.css.filterRow).toggle( !(wo.filter_hideEmpty && $.isEmptyObject(c.cache)) ); // fixes #450
+			if ( !/(search|filter)/.test(event.type) ) {
 				event.stopPropagation();
 				ts.filter.buildDefault(table, true);
 			}
@@ -571,6 +571,10 @@ ts.filter = {
 			} else {
 				// send false argument to force a new search; otherwise if the filter hasn't changed, it will return
 				filter = event.type === 'search' ? filter : event.type === 'updateComplete' ? c.$table.data('lastSearch') : '';
+				if (/(update|add)/.test(event.type)) {
+					// force a new search since content has changed
+					c.lastCombinedFilter = null;
+				}
 				// pass true (dontSkip) to prevent the tablesorter.setFilters function from skipping the first input
 				// ensures all inputs are updated when a search is triggered on the table $('table').trigger('search', [...]);
 				ts.filter.searching(table, filter, true);

js/widgets/widget-pager.js

@@ -301,10 +301,10 @@ tsp = ts.pager = {
 		var p = c.pager,
 			dis = !!disable,
 			first = dis || p.page === 0,
+			tp = Math.min( p.totalPages, p.filteredPages ),
 			last = dis || p.page === tp - 1 || p.totalPages === 0,
 			wo = c.widgetOptions,
-			s = wo.pager_selectors,
-			tp = Math.min( p.totalPages, p.filteredPages );
+			s = wo.pager_selectors;
 		if ( wo.pager_updateArrows ) {
 			p.$container.find(s.first + ',' + s.prev).toggleClass(wo.pager_css.disabled, first).attr('aria-disabled', first);
 			p.$container.find(s.next + ',' + s.last).toggleClass(wo.pager_css.disabled, last).attr('aria-disabled', last);
@@ -695,7 +695,10 @@ tsp = ts.pager = {
 		// don't allow rendering multiple times on the same page/size/totalpages/filters/sorts
 		if ( l.page === p.page && l.size === p.size && l.totalPages === p.totalPages &&
 			(l.currentFilters || []).join(',') === (p.currentFilters || []).join(',') &&
-			l.sortList === (c.sortList || []).join(',') ) { return; }
+			l.sortList === (c.sortList || []).join(',') ) {
+				// make sure widgets are applied - fixes #450
+				return flag === true ? c.$table.trigger('applyWidgets') : '';
+			}
 		if (c.debug) {
 			ts.log('Pager changing to page ' + p.page);
 		}
@@ -801,7 +804,9 @@ tsp = ts.pager = {
 			p.totalRows = c.widgetOptions.pager_countChildRows ? c.$tbodies.eq(0).children().length : rows.length;
 			p.size = $.data(table, 'pagerLastSize') || p.size || wo.pager_size || 10;
 			p.totalPages = Math.ceil( p.totalRows / p.size );
-			tsp.moveToPage(table, p);
+			tsp.moveToPage(table, p, true);
+			// update display here in case all rows are removed
+			tsp.updatePageDisplay(table, c, false);
 		}
 	}