From 4e1c96d4378fd2dbb65ad3c07c17d519517fd4de Mon Sep 17 00:00:00 2001
From: Rob Garrison <wowmotty@gmail.com>
Date: Sat, 12 Dec 2015 20:41:27 -0600
Subject: [PATCH] Math: lots of tweaks. See #1083

- Initial calculation performed once - changed binding to either "filterEnd"
  or "pagerComplete", not both.
- Added change flag so a cache update is only performed when cell content
  inside of a sortable tbody was modified.
- Fix data-math-filter on "all" cell calculation with fixes to getRow &
  getColumn functions so that filters get priority over the "filtered" row
  check.
---
 docs/example-widget-math.html |  70 ++++++++++-----
 js/widgets/widget-math.js     | 160 +++++++++++++++++++++-------------
 2 files changed, 150 insertions(+), 80 deletions(-)

diff --git a/docs/example-widget-math.html b/docs/example-widget-math.html
index a51614b4..86e5ffb8 100644
--- a/docs/example-widget-math.html
+++ b/docs/example-widget-math.html
@@ -18,7 +18,7 @@
 	<!-- Tablesorter: required -->
 	<link rel="stylesheet" href="../css/theme.blue.css">
 	<script src="../js/jquery.tablesorter.js"></script>
-	<script src="../js/jquery.tablesorter.widgets.js"></script>
+	<script src="../js/widgets/widget-filter.js"></script>
 
 	<script src="../js/widgets/widget-math.js"></script>
 
@@ -182,7 +182,15 @@
 			<li>In <span class="version">v2.24.7</span>
 				<ul>
 					<li><code>math_rowFilter</code> can now be overridden by the row's <code>data-math-filter</code> attribute.</li>
-					<li>On initialization, only tbody cells with a <code>rowspan</code> or <code>colspan</code> are now processed and only get a "data-column" set if the internal <code>cellIndex</code> doesn't match the calculated cell index. This should improve performance and reduce lag after initialization and updating the table (see <a href="https://github.com/Mottie/tablesorter/issues/1048">issue #1048</a>.</li>
+					<li>
+						Lots of optimizations!
+						<ul>
+							<li>On initialization, only tbody cells with a <code>rowspan</code> or <code>colspan</code> are now processed and only get a "data-column" set if the internal <code>cellIndex</code> doesn't match the calculated cell index.</li>
+							<li>Initial calculation is no longer performed three times in a row</li>
+							<li>The cache is now only updated if cell content inside of a sortable tbody was modified.</li>
+							<li>These changes should improve performance and reduce lag after initialization and updating the table (see <a href="https://github.com/Mottie/tablesorter/issues/1048">issue #1048</a>.</li>
+						</ul>
+					</li>
 				</ul>
 			</li>
 			<li>In <span class="version">v2.24.6</span>, added <code>math_rowFilter</code> option.</li>
@@ -192,25 +200,36 @@
 					<li>Added <code>math_none</code> option which allows customizing the text added to a cell when there are no matching math elements (.</li>
 				</ul>
 			</li>
-			<li>In <span class="version updated">v2.22.0</span>,
+		</ul>
+
+		<div class="accordion start-closed">
+			<h3 id="old-notes"><a href="#">Older Notes</a></h3>
+			<div>
 				<ul>
-					<li>Fixed an issue with a sum column encountering a cell without a defined "data-math" attribute returning an empty string instead of zero. See <a href="https://github.com/Mottie/tablesorter/issues/873">issue #873</a>.</li>
-					<li>Fixed a javascript error occurring on empty tables & now all updates will reapply column indexing to tbody cells - I know this isn't ideal as it would be slow on larger tables.</li>
+					<li>In <span class="version updated">v2.22.0</span>,
+						<ul>
+							<li>Fixed an issue with a sum column encountering a cell without a defined "data-math" attribute returning an empty string instead of zero. See <a href="https://github.com/Mottie/tablesorter/issues/873">issue #873</a>.</li>
+							<li>Fixed a javascript error occurring on empty tables & now all updates will reapply column indexing to tbody cells - I know this isn't ideal as it would be slow on larger tables.</li>
+						</ul>
+					</li>
+					<li>In <span class="version">v2.19.1</span>, added <code>math_event</code> option &amp; fixed an issue with event unbinding in jQuery version &lt; 1.9.</li>
+					<li>In <span class="version">v2.17.1</span>,
+						<ul>
+							<li>Values added to the data-attribute set by the <a href="../#textattribute"><code>textAttribute</code> option</a> will now be used in the calculation instead of the actual cell content.</li>
+							<li>The Grand Total cells now shows a higher precision value to emphasize this point.</li>
+						</ul>
+					</li>
+					<li>In <span class="version">v2.16.4</span>, added:
+						<ul>
+							<li>Two new options: <code>math_prefix</code> and <code>math_suffix</code>, which will be added before or after the prefix or suffix, respectively.</li>
+							<li>Added "Mask Examples" section with examples, and how to use the <code>$.tablesorter.formatMask</code> function.</li>
+						</ul>
+					</li>
 				</ul>
-			</li>
-			<li>In <span class="version">v2.19.1</span>, added <code>math_event</code> option &amp; fixed an issue with event unbinding in jQuery version &lt; 1.9.</li>
-			<li>In <span class="version">v2.17.1</span>,
-				<ul>
-					<li>Values added to the data-attribute set by the <a href="../#textattribute"><code>textAttribute</code> option</a> will now be used in the calculation instead of the actual cell content.</li>
-					<li>The Grand Total cells now shows a higher precision value to emphasize this point.</li>
-				</ul>
-			</li>
-			<li>In <span class="version">v2.16.4</span>, added:
-				<ul>
-					<li>Two new options: <code>math_prefix</code> and <code>math_suffix</code>, which will be added before or after the prefix or suffix, respectively.</li>
-					<li>Added "Mask Examples" section with examples, and how to use the <code>$.tablesorter.formatMask</code> function.</li>
-				</ul><br>
-			</li>
+			</div>
+		</div>
+
+		<ul>
 			<li>This widget will <strong>only work</strong> in tablesorter version 2.16+ and jQuery version 1.7+.</li>
 			<li>It adds basic math capabilities. A full list of default formulas is listed in the "Attribute Settings" section.</li>
 			<li>Add your own custom formulas which manipulating an array of values gathered from the table by row, column or a column block (above).</li>
@@ -218,7 +237,7 @@
 			<li>The widget will update the calculations based on filtered rows, and will update if any data within the table changes (using update events).</li>
 			<li>This widget is not optimized for very large tables, for two reasons:
 				<ul>
-					<li>On initialization, it cycles through every table row, calculates the column index<del>, and adds a <code>data-column</code> attribute</del> (Fixed in <span class="version updated">v2.24.7</span>).</li>
+					<li>On initialization, it cycles through every table row, calculates the column index <del>, and adds a <code>data-column</code> attribute</del> (Fixed in <span class="version updated">v2.24.7</span>).</li>
 					<li>It uses the update method whenever it recalculates values to make the results sortable. This occurs when any of the update methods are used and after the table is filtered.</li>
 				</ul>
 			</li>
@@ -442,6 +461,7 @@ math_suffix : '{content}<span class="red">!</span>'
 math_rowFilter : ':visible:not(.filtered)'</pre>
 								In <span class="version">v2.24.7</span>, this setting my be overridden in specific rows by adding a <code>data-math-filter</code> attribute (The "math" portion is set by the <code>math_data</code> option)
 								<pre class="prettyprint lang-html">&lt;tr data-math-filter=":visible"&gt;...&lt;/tr&gt;</pre>
+								<span class="label label-info">Note</span> The <code>data-math-filter</code> attribute is ignored if set to an empty string; instead use <code>data-math-filter="*"</code> to target all rows as done in the first example on this page.
 							</div>
 						</td>
 					</tr>
@@ -580,9 +600,17 @@ BAD =&gt; No minus (-) here! $#,###.00 or [-] here either &lt;= BAD</textarea>
 			<th data-math="col-sum">col-sum</th>
 			<th data-math="col-sum">col-sum</th>
 		</tr>
+		<tr>
+			<th colspan="5">Visible Total</th>
+			<th data-math="all-sum"></th>
+		</tr>
 		<tr>
 			<th colspan="5">Grand Total</th>
-			<th data-math="all-sum" data-math-mask="##0.0000">all-sum</th>
+			<!--
+			The "data-math-filter" attribute can not be set to an empty string AND override the widgetOptions.math_rowFilter,
+			so set to to an asterisk ("*") to target all rows.
+			-->
+			<th data-math="all-sum" data-math-filter="*" data-math-mask="##0.0000"></th>
 		</tr>
 	</tfoot>
 
diff --git a/js/widgets/widget-math.js b/js/widgets/widget-math.js
index 8790781b..9b3aa052 100644
--- a/js/widgets/widget-math.js
+++ b/js/widgets/widget-math.js
@@ -25,8 +25,8 @@
 			return c && c.widgetOptions.math_none || 'none'; // text for cell
 		},
 
-		events : ( 'tablesorter-initialized update updateAll updateRows addRows updateCell ' +
-			'filterReset filterEnd ' ).split(' ').join('.tsmath '),
+		events : ( 'tablesorter-initialized update updateAll updateRows addRows updateCell filterReset ' )
+			.split(' ').join('.tsmath '),
 
 		processText : function( c, $cell ) {
 			var txt = ts.getElementText( c, $cell, math.getCellIndex( $cell ) );
@@ -36,17 +36,16 @@
 		},
 
 		// get all of the row numerical values in an arry
-		getRow : function( c, $el ) {
+		getRow : function( c, $el, hasFilter ) {
 			var $cells,
 				wo = c.widgetOptions,
 				arry = [],
 				$row = $el.closest( 'tr' ),
-				isFiltered = $row.hasClass( wo.filter_filteredRow || 'filtered' ),
-				hasFilter = $row.attr( wo.math_dataAttrib + '-filter' ) || wo.math_rowFilter;
+				isFiltered = $row.hasClass( wo.filter_filteredRow || 'filtered' );
 			if ( hasFilter ) {
 				$row = $row.filter( hasFilter );
 			}
-			if ( !isFiltered || hasFilter ) {
+			if ( hasFilter || !isFiltered ) {
 				$cells = $row.children().not( '[' + wo.math_dataAttrib + '=ignore]' );
 				if ( wo.math_ignore.length ) {
 					$cells = $cells.filter( function( indx ) {
@@ -62,33 +61,38 @@
 		},
 
 		// get all of the column numerical values in an arry
-		getColumn : function( c, $el, type ) {
+		getColumn : function( c, $el, type, hasFilter ) {
 			var index, $t, $tr, len, $mathRows, mathAbove,
 				wo = c.widgetOptions,
 				arry = [],
 				$row = $el.closest( 'tr' ),
 				mathAttr = wo.math_dataAttrib,
-				hasFilter = $row.attr( mathAttr + '-filter' ) || wo.math_rowFilter,
+				mathIgnore = '[' + mathAttr + '=ignore]',
 				filtered = wo.filter_filteredRow || 'filtered',
 				cIndex = math.getCellIndex( $el ),
-				$rows = c.$table.children( 'tbody' ).children();
-			// make sure tfoot rows are AFTER the tbody rows
-			// $rows.add( c.$table.children( 'tfoot' ).children() );
+				// get all rows to keep row indexing
+				$rows = c.$table.children( 'tbody' ).children(),
+				mathAttrs = [
+					'[' + mathAttr + '^=above]',
+					'[' + mathAttr + '^=below]',
+					'[' + mathAttr + '^=col]',
+					'[' + mathAttr + '^=all]'
+				];
 			if ( type === 'above' ) {
 				len = $rows.index( $row );
 				index = len;
 				while ( index >= 0 ) {
 					$tr = $rows.eq( index );
+					mathAbove = $tr.children().filter( mathAttrs[0] ).length;
 					if ( hasFilter ) {
 						$tr = $tr.filter( hasFilter );
 					}
 					$t = $tr.children().filter( function( indx ) {
 						return math.getCellIndex( $( this ) ) === cIndex;
 					});
-					mathAbove = $t.filter( '[' + mathAttr + '^=above]' ).length;
 					// ignore filtered rows & rows with data-math="ignore" (and starting row)
-					if ( ( ( !$tr.hasClass( filtered ) || hasFilter ) &&
-							$tr.not( '[' + mathAttr + '=ignore]' ).length &&
+					if ( ( ( hasFilter || !$tr.hasClass( filtered ) ) &&
+							$tr.not( mathIgnore ).length &&
 							index !== len ) ||
 							mathAbove && index !== len ) {
 						// stop calculating 'above', when encountering another 'above'
@@ -105,24 +109,23 @@
 				// index + 1 to ignore starting node
 				for ( index = $rows.index( $row ) + 1; index < len; index++ ) {
 					$tr = $rows.eq( index );
+					if ( $tr.children().filter( mathAttrs[1] ).length ) {
+						break;
+					}
 					if ( hasFilter ) {
 						$tr = $tr.filter( hasFilter );
 					}
 					$t = $tr.children().filter( function( indx ) {
 						return math.getCellIndex( $( this ) ) === cIndex;
 					});
-					if ( $t.filter( '[' + mathAttr + '^=below]' ).length ) {
-						break;
-					}
-					if ( ( !$tr.hasClass( filtered ) || hasFilter ) &&
-							$tr.not( '[' + mathAttr + '=ignore]' ).length &&
-							$t.length ) {
+					if ( ( hasFilter || !$tr.hasClass( filtered ) ) &&
+						$tr.not( mathIgnore ).length &&
+						$t.length ) {
 						arry.push( math.processText( c, $t ) );
 					}
 				}
-
 			} else {
-				$mathRows = $rows.not( '[' + mathAttr + '=ignore]' );
+				$mathRows = $rows.not( mathIgnore );
 				len = $mathRows.length;
 				for ( index = 0; index < len; index++ ) {
 					$tr = $mathRows.eq( index );
@@ -132,8 +135,8 @@
 					$t = $tr.children().filter( function( indx ) {
 						return math.getCellIndex( $( this ) ) === cIndex;
 					});
-					if ( ( !$tr.hasClass( filtered ) || hasFilter ) &&
-						$t.not( '[' + mathAttr + '^=above],[' + mathAttr + '^=below],[' + mathAttr + '^=col]' ).length &&
+					if ( ( hasFilter || !$tr.hasClass( filtered ) ) &&
+						$t.not( mathAttrs.join( ',' ) ).length &&
 						!$t.is( $el ) ) {
 						arry.push( math.processText( c, $t ) );
 					}
@@ -143,22 +146,22 @@
 		},
 
 		// get all of the column numerical values in an arry
-		getAll : function( c ) {
+		getAll : function( c, hasFilter ) {
 			var $t, col, $row, rowIndex, rowLen, $cells, cellIndex, cellLen,
 				arry = [],
 				wo = c.widgetOptions,
 				mathAttr = wo.math_dataAttrib,
+				mathIgnore = '[' + mathAttr + '=ignore]',
 				filtered = wo.filter_filteredRow || 'filtered',
-				hasFilter = wo.filter_rowFilter,
-				$rows = c.$table.children( 'tbody' ).children().not( '[' + mathAttr + '=ignore]' );
+				$rows = c.$table.children( 'tbody' ).children().not( mathIgnore );
 			rowLen = $rows.length;
 			for ( rowIndex = 0; rowIndex < rowLen; rowIndex++ ) {
 				$row = $rows.eq( rowIndex );
 				if ( hasFilter ) {
 					$row = $row.filter( hasFilter );
 				}
-				if ( !$row.hasClass( filtered ) || hasFilter ) {
-					$cells = $row.children().not( '[' + mathAttr + '=ignore]' );
+				if ( hasFilter || !$row.hasClass( filtered ) ) {
+					$cells = $row.children().not( mathIgnore );
 					cellLen = $cells.length;
 					// $row.children().each(function(){
 					for ( cellIndex = 0; cellIndex < cellLen; cellIndex++ ) {
@@ -215,7 +218,9 @@
 		recalculate : function(c, wo, init) {
 			if ( c && ( !wo.math_isUpdating || init ) ) {
 
-				var undef, time, mathAttr, $mathCells;
+				var undef, time, mathAttr, $mathCells, indx, len,
+					changed = false,
+					filters = {};
 				if ( c.debug ) {
 					time = new Date();
 				}
@@ -231,7 +236,7 @@
 				// all non-info tbody cells
 				mathAttr = wo.math_dataAttrib;
 				$mathCells = c.$tbodies.children( 'tr' ).children( '[' + mathAttr + ']' );
-				math.mathType( c, $mathCells, wo.math_priority );
+				changed = changed || math.mathType( c, $mathCells, wo.math_priority );
 
 				// only info tbody cells
 				$mathCells = c.$table
@@ -242,20 +247,33 @@
 
 				// find the 'all' total
 				$mathCells = c.$table.children().children( 'tr' ).children( '[' + mathAttr + '^=all]' );
-				math.mathType( c, $mathCells, [ 'all' ] );
-
-				wo.math_isUpdating = true;
-				if ( c.debug ) {
-					console[ console.group ? 'group' : 'log' ]( 'Math widget triggering an update after recalculation' );
-				}
-
-				// update internal cache
-				ts.update( c, undef, function(){
-					math.updateComplete( c );
+				len = $mathCells.length;
+				// get math filter, if any
+				// hasFilter = $row.attr( mathAttr + '-filter' ) || wo.math_rowFilter;
+				$mathCells.each( function( indx, cell ) {
+					var $cell = $( cell ),
+						filter = $mathCells.eq( indx ).attr( mathAttr + '-filter' ) || wo.math_rowFilter;
+					filters[ filter ] = filters[ filter ] ? filters[ filter ].add( $cell ) : $cell;
+				});
+				$.each( filters, function( hasFilter, $cells ) {
+					changed = changed || math.mathType( c, $cells, [ 'all' ], hasFilter );
 				});
 
-				if ( c.debug ) {
-					console.log( 'Math widget update completed' + ts.benchmark( time ) );
+				// trigger an update only if cells inside the tbody changed
+				if ( changed ) {
+					wo.math_isUpdating = true;
+					if ( c.debug ) {
+						console[ console.group ? 'group' : 'log' ]( 'Math widget triggering an update after recalculation' );
+					}
+
+					// update internal cache
+					ts.update( c, undef, function(){
+						math.updateComplete( c );
+					});
+
+					if ( c.debug ) {
+						console.log( 'Math widget update completed' + ts.benchmark( time ) );
+					}
 				}
 			}
 		},
@@ -266,23 +284,25 @@
 			wo.math_isUpdating = false;
 		},
 
-		mathType : function( c, $cells, priority ) {
+		mathType : function( c, $cells, priority, hasFilter ) {
 			if ( $cells.length ) {
-				var formula, result, $el, arry, getAll, $targetCells, index, len,
+				var getAll,
+					changed = false,
 					wo = c.widgetOptions,
 					mathAttr = wo.math_dataAttrib,
 					equations = ts.equations;
 				if ( priority[0] === 'all' ) {
-					// no need to get all cells more than once
-					getAll = math.getAll( c );
+					// mathType is called multiple times if more than one "hasFilter" is used
+					getAll = math.getAll( c, hasFilter );
 				}
 				if (c.debug) {
 					console[ console.group ? 'group' : 'log' ]( 'Tablesorter Math widget recalculation' );
 				}
 				// $.each is okay here... only 4 priorities
 				$.each( priority, function( i, type ) {
-					$targetCells = $cells.filter( '[' + mathAttr + '^=' + type + ']' );
-					len = $targetCells.length;
+					var index, arry, formula, result, $el,
+						$targetCells = $cells.filter( '[' + mathAttr + '^=' + type + ']' ),
+						len = $targetCells.length;
 					if ( len ) {
 						if (c.debug) {
 							console[ console.group ? 'group' : 'log' ]( type );
@@ -293,39 +313,58 @@
 							if ( $el.parent().hasClass( wo.filter_filteredRow || 'filtered' ) ) {
 								continue;
 							}
+							hasFilter = hasFilter || $el.attr( mathAttr + '-filter' ) || wo.math_rowFilter;
 							formula = ( $el.attr( mathAttr ) || '' ).replace( type + '-', '' );
-							arry = ( type === 'row' ) ? math.getRow( c, $el ) :
-								( type === 'all' ) ? getAll : math.getColumn( c, $el, type );
+							arry = ( type === 'row' ) ? math.getRow( c, $el, hasFilter ) :
+								( type === 'all' ) ? getAll : math.getColumn( c, $el, type, hasFilter );
 							if ( equations[ formula ] ) {
 								if ( arry.length ) {
 									result = equations[ formula ]( arry, c );
 									if ( c.debug ) {
-										console.log( $el.attr( mathAttr ), arry, '=', result );
+										console.log( $el.attr( mathAttr ), hasFilter ? '("' + hasFilter + '")' : '', arry, '=', result );
 									}
 								} else {
 									// mean will return a divide by zero error, everything else shows an undefined error
 									result = math.invalid( c, formula, formula === 'mean' ? 0 : 'undef' );
 								}
-								math.output( $el, wo, result, arry );
+								changed = math.output( $el, c, result, arry ) || changed;
 							}
 						}
 						if ( c.debug && console.groupEnd ) { console.groupEnd(); }
 					}
 				});
 				if ( c.debug && console.groupEnd ) { console.groupEnd(); }
+				return changed;
 			}
+			return false;
 		},
 
-		output : function( $cell, wo, value, arry ) {
+		output : function( $cell, c, value, arry ) {
 			// get mask from cell data-attribute: data-math-mask="#,##0.00"
-			var mask = $cell.attr( 'data-' + wo.math_data + '-mask' ) || wo.math_mask,
+			var $el,
+				wo = c.widgetOptions,
+				changed = false,
+				prev = $cell.html(),
+				mask = $cell.attr( 'data-' + wo.math_data + '-mask' ) || wo.math_mask,
 				result = ts.formatMask( mask, value, wo.math_wrapPrefix, wo.math_wrapSuffix );
 			if ( typeof wo.math_complete === 'function' ) {
 				result = wo.math_complete( $cell, wo, result, value, arry );
 			}
 			if ( result !== false ) {
+				changed = prev !== result;
 				$cell.html( result );
 			}
+			// check if in a regular tbody, otherwise don't pass a changed flag
+			// to prevent unnecessary updating of the table cache
+			if ( changed ) {
+				$el = $cell.closest( 'tbody' );
+				// content was changed in a tfoot, info-only tbody or the resulting tbody is in a nested table
+				// then don't signal a change
+				if ( !$el.length || $el.hasClass( c.cssInfoBlock ) || $el.parent()[0] !== c.table ) {
+					return false;
+				}
+			}
+			return changed;
 		}
 
 	};
@@ -560,10 +599,13 @@
 		},
 		init : function( table, thisWidget, c, wo ) {
 			// filterEnd fires after updateComplete
-			var update = ts.hasWidget( table, 'filter' ) ? 'filterEnd' : 'updateComplete';
+			var update = ( ts.hasWidget( table, 'filter' ) ? 'filterEnd' : 'updateComplete' ) + '.tsmath';
+			// filterEnd is when the pager hides rows... so bind to pagerComplete
+			math.events += ( ts.hasWidget( table, 'pager' ) ? 'pagerComplete' : 'filterEnd' ) + '.tsmath ';
 			c.$table
-				.off( ( math.events + ' updateComplete.tsmath ' + wo.math_event ).replace( /\s+/g, ' ' ) )
-				.on( math.events + ' ' + wo.math_event, function( e ) {
+				.off( ( math.events + 'updateComplete.tsmath ' + wo.math_event ).replace( /\s+/g, ' ' ) )
+				.on( math.events + wo.math_event, function( e ) {
+					if ( !this.hasInitialized ) { return; }
 					var init = e.type === 'tablesorter-initialized';
 					if ( !wo.math_isUpdating || init ) {
 						// don't setColumnIndexes on init here, or it gets done twice
@@ -574,7 +616,7 @@
 						math.recalculate( c, wo, init );
 					}
 				})
-				.on( update + '.tsmath', function() {
+				.on( update, function() {
 					setTimeout( function(){
 						math.updateComplete( c );
 					}, 40 );