Storage & Build widget: pass "null" to $.parseJSON as a fallback. Fixes

#586

Also change build widget example code to use dataType:"text" for csv data

docs/example-widget-build-table.html

@@ -281,7 +281,7 @@ <h3>Notes</h3>
 					<ul>
 						<li>(<code>build_headers</code> &amp; <code>build_footers</code>) have been added allowing customizing the headers and/or footers.</li>
 						<li>The <code>rows</code> option sets the number of headers rows to include from the data source. <strong>Zero is not an option</strong> since tablesorter requires a thead in place before it will initialize.</li>
-						<li>The <code>classes</code> array sets each header cell (<code>th</code>) class name.</li> 
+						<li>The <code>classes</code> array sets each header cell (<code>th</code>) class name.</li>
 						<li>The <code>text</code> array within these options will override any text obtained from the data source.</li>
 						<li>The <code>widths</code> array, only in the <code>build_headers</code> option, sets column widths by building <code>&lt;col&gt;</code> elements within a <code>&lt;colgroup</code>.</li>
 						<li>Adding class names to the tbody rows or cells isn't easily accomplished, but you can bind to the build complete event (<code>'tablesorter-build-complete'</code>) and add them yourself.</li>
@@ -383,7 +383,7 @@ <h3>Notes</h3>
 							<ul>
 								<li>(<code>build_headers</code> &amp; <code>build_footers</code>) have been added allowing customizing the headers and/or footers.</li>
 								<li>The <code>rows</code> option sets the number of headers rows to include from the data source. <strong>Zero is not an option</strong> since tablesorter requires a thead in place before it will initialize.</li>
-								<li>The <code>classes</code> array sets each header cell (<code>th</code>) class name.</li> 
+								<li>The <code>classes</code> array sets each header cell (<code>th</code>) class name.</li>
 								<li>The <code>text</code> array within these options will override any text obtained from the data source.</li>
 								<li>The <code>widths</code> array, only in the <code>build_headers</code> option, sets column widths by building <code>&lt;col&gt;</code> elements within a <code>&lt;colgroup</code>.</li>
 								<li>Adding class names to the tbody rows or cells isn't easily accomplished, but you can bind to the build complete event (<code>'tablesorter-build-complete'</code>) and add them yourself.</li>
@@ -502,7 +502,7 @@ <h3>Javascript</h3>
 		widgetOptions: {
 			// *** build widget core ***
 			build_type      : 'csv',
-			build_source    : { url: 'assets/csv.txt', dataType: 'html' },
+			build_source    : { url: 'assets/csv.txt', dataType: 'text' },
 			build_headers   : {
 				widths  : ['30%', '50%', '20%'] // set header cell widths
 			}

docs/js/demo-build-table.js

@@ -43,7 +43,7 @@ $(function(){
 				var rows = data.split(';');
 				return $.each(rows, function(i,cells) {
 					// similar to using rows[i] = cells.split(',') but the splitCSV script
-					// doesn't split the cell if the separator (comma) is within quotes 
+					// doesn't split the cell if the separator (comma) is within quotes
 					rows[i] = $.tablesorter.buildTable.splitCSV(cells, ',');
 				});
 			}
@@ -94,7 +94,7 @@ $(function(){
 		widgetOptions: {
 			// *** build widget core ***
 			build_type      : 'csv',
-			build_source    : { url: 'assets/build.txt', dataType: 'html' },
+			build_source    : { url: 'assets/build.txt', dataType: 'text' },
 			build_headers   : {
 				widths : ['30%', '50%', '20%'] // set header cell widths
 			}

js/jquery.tablesorter.widgets.js

@@ -110,13 +110,13 @@ ts.storage = function(table, key, value, options) {
 	// *** get value ***
 	if ($.parseJSON) {
 		if (hasLocalStorage) {
-			values = $.parseJSON(localStorage[key] || '{}');
+			values = $.parseJSON(localStorage[key] || 'null') || {};
 		} else {
 			// old browser, using cookies
 			cookies = document.cookie.split(/[;\s|=]/);
 			// add one to get from the key to the value
 			cookieIndex = $.inArray(key, cookies) + 1;
-			values = (cookieIndex !== 0) ? $.parseJSON(cookies[cookieIndex] || '{}') : {};
+			values = (cookieIndex !== 0) ? $.parseJSON(cookies[cookieIndex] || 'null') || {} : {};
 		}
 	}
 	// allow value to be an empty string too

js/widgets/widget-build-table.js

@@ -34,7 +34,7 @@ var ts = $.tablesorter = $.tablesorter || {},
 					return bt.html( table, d, wo );
 				}
 				try {
-					d = $.parseJSON(d);
+					d = $.parseJSON(d || 'null');
 					if (d) {
 						// valid JSON!
 						return bt.object( table, d, wo );