页面刷新后保留 table 排序结果？
Keep table sort result after page refresh?
我正在使用来自 w3.js(https://www.w3schools.com/howto/howto_js_sort_table.asp) 的 table 分拣机。
另外，我已经使用 setTimeout 来每分钟刷新页面以更新数据。
我想保留刷新页面后的排序结果
我知道有一种方法是使用sessionStorage，但是不知道怎么用
谁能给我一些提示？
下面是 SortTable. We use the browser cookies to restore the last sort information, which are mainly the sorting column and direction. There is another example in W3school, from which I got the cookie handling (Cookies) 中示例的更新片段。由于跨源政策，下面的代码片段在网站上不起作用。当然，它也需要一些重构，但这是一个开始。
<!DOCTYPE html>
<html>
<head>
<title>Sort a HTML Table Alphabetically</title>
<style>
table {
border-spacing: 0;
width: 100%;
border: 1px solid #ddd;
}
th {
cursor: pointer;
}
th, td {
text-align: left;
padding: 16px;
}
tr:nth-child(even) {
background-color: #f2f2f2
}
</style>
</head>
<body onload="checkCookie();">
<p><strong>Click the headers to sort the table.</strong></p>
<p>The first time you click, the sorting direction is ascending (A to Z).</p>
<p>Click again, and the sorting direction will be descending (Z to A):</p>
<table id="myTable">
<tr>
<!--When a header is clicked, run the sortTable function, with a parameter, 0 for sorting by names, 1 for sorting by country:-->
<th onclick="sortTable(0)">Name</th>
<th onclick="sortTable(1)">Country</th>
</tr>
<tr>
<td>Berglunds snabbkop</td>
<td>Sweden</td>
</tr>
<tr>
<td>North/South</td>
<td>UK</td>
</tr>
<tr>
<td>Alfreds Futterkiste</td>
<td>Germany</td>
</tr>
<tr>
<td>Koniglich Essen</td>
<td>Germany</td>
</tr>
<tr>
<td>Magazzini Alimentari Riuniti</td>
<td>Italy</td>
</tr>
<tr>
<td>Paris specialites</td>
<td>France</td>
</tr>
<tr>
<td>Island Trading</td>
<td>UK</td>
</tr>
<tr>
<td>Laughing Bacchus Winecellars</td>
<td>Canada</td>
</tr>
</table>
<script>
function sortTable(n, dir) {
var table, rows, switching, i, x, y, shouldSwitch, dir, switchcount = 0;
table = document.getElementById("myTable");
switching = true;
//Set the sorting direction to ascending:
!dir && (dir = "asc");
/*Make a loop that will continue until
no switching has been done:*/
while (switching) {
//start by saying: no switching is done:
switching = false;
rows = table.getElementsByTagName("TR");
/*Loop through all table rows (except the
first, which contains table headers):*/
for (i = 1; i < (rows.length - 1); i++) {
//start by saying there should be no switching:
shouldSwitch = false;
/*Get the two elements you want to compare,
one from current row and one from the next:*/
x = rows[i].getElementsByTagName("TD")[n];
y = rows[i + 1].getElementsByTagName("TD")[n];
/*check if the two rows should switch place,
based on the direction, asc or desc:*/
if (dir == "asc") {
if (x.innerHTML.toLowerCase() > y.innerHTML.toLowerCase()) {
//if so, mark as a switch and break the loop:
shouldSwitch= true;
break;
}
} else if (dir == "desc") {
if (x.innerHTML.toLowerCase() < y.innerHTML.toLowerCase()) {
//if so, mark as a switch and break the loop:
shouldSwitch= true;
break;
}
}
}
if (shouldSwitch) {
/*If a switch has been marked, make the switch
and mark that a switch has been done:*/
rows[i].parentNode.insertBefore(rows[i + 1], rows[i]);
switching = true;
//Each time a switch is done, increase this count by 1:
switchcount ++;
} else {
/*If no switching has been done AND the direction is "asc",
set the direction to "desc" and run the while loop again.*/
if (switchcount == 0 && dir == "asc") {
dir = "desc";
switching = true;
}
}
}
setCookie("sortBy", n, 30);
setCookie("sortByDir", dir);
}
function setCookie(cname,cvalue,exdays) {
var d = new Date();
d.setTime(d.getTime() + (exdays*24*60*60*1000));
var expires = "expires=" + d.toGMTString();
document.cookie = cname + "=" + cvalue + ";" + expires + ";path=/";
}
function getCookie(cname) {
var name = cname + "=";
var decodedCookie = decodeURIComponent(document.cookie);
var ca = decodedCookie.split(';');
for(var i = 0; i < ca.length; i++) {
var c = ca[i];
while (c.charAt(0) == ' ') {
c = c.substring(1);
}
if (c.indexOf(name) == 0) {
return c.substring(name.length, c.length);
}
}
return "";
}
function checkCookie() {
var sortBy=getCookie("sortBy");
if (sortBy != "") {
sortTable(parseInt(sortBy), getCookie("sortByDir"));
}
}
</script>
</body>
</html>
编辑：
另一个使用 sessionStorage 的片段
<!DOCTYPE html>
<html>
<head>
<title>Sort a HTML Table Alphabetically</title>
<style>
table {
border-spacing: 0;
width: 100%;
border: 1px solid #ddd;
}
th {
cursor: pointer;
}
th, td {
text-align: left;
padding: 16px;
}
tr:nth-child(even) {
background-color: #f2f2f2
}
</style>
</head>
<body onload="checkStrorage();">
<p><strong>Click the headers to sort the table.</strong></p>
<p>The first time you click, the sorting direction is ascending (A to Z).</p>
<p>Click again, and the sorting direction will be descending (Z to A):</p>
<table id="myTable">
<tr>
<!--When a header is clicked, run the sortTable function, with a parameter, 0 for sorting by names, 1 for sorting by country:-->
<th onclick="sortTable(0)">Name</th>
<th onclick="sortTable(1)">Country</th>
</tr>
<tr>
<td>Berglunds snabbkop</td>
<td>Sweden</td>
</tr>
<tr>
<td>North/South</td>
<td>UK</td>
</tr>
<tr>
<td>Alfreds Futterkiste</td>
<td>Germany</td>
</tr>
<tr>
<td>Koniglich Essen</td>
<td>Germany</td>
</tr>
<tr>
<td>Magazzini Alimentari Riuniti</td>
<td>Italy</td>
</tr>
<tr>
<td>Paris specialites</td>
<td>France</td>
</tr>
<tr>
<td>Island Trading</td>
<td>UK</td>
</tr>
<tr>
<td>Laughing Bacchus Winecellars</td>
<td>Canada</td>
</tr>
</table>
<script>
function sortTable(n, dir) {
var table, rows, switching, i, x, y, shouldSwitch, dir, switchcount = 0;
table = document.getElementById("myTable");
switching = true;
//Set the sorting direction to ascending:
!dir && (dir = "asc");
/*Make a loop that will continue until
no switching has been done:*/
while (switching) {
//start by saying: no switching is done:
switching = false;
rows = table.getElementsByTagName("TR");
/*Loop through all table rows (except the
first, which contains table headers):*/
for (i = 1; i < (rows.length - 1); i++) {
//start by saying there should be no switching:
shouldSwitch = false;
/*Get the two elements you want to compare,
one from current row and one from the next:*/
x = rows[i].getElementsByTagName("TD")[n];
y = rows[i + 1].getElementsByTagName("TD")[n];
/*check if the two rows should switch place,
based on the direction, asc or desc:*/
if (dir == "asc") {
if (x.innerHTML.toLowerCase() > y.innerHTML.toLowerCase()) {
//if so, mark as a switch and break the loop:
shouldSwitch= true;
break;
}
} else if (dir == "desc") {
if (x.innerHTML.toLowerCase() < y.innerHTML.toLowerCase()) {
//if so, mark as a switch and break the loop:
shouldSwitch= true;
break;
}
}
}
if (shouldSwitch) {
/*If a switch has been marked, make the switch
and mark that a switch has been done:*/
rows[i].parentNode.insertBefore(rows[i + 1], rows[i]);
switching = true;
//Each time a switch is done, increase this count by 1:
switchcount ++;
} else {
/*If no switching has been done AND the direction is "asc",
set the direction to "desc" and run the while loop again.*/
if (switchcount == 0 && dir == "asc") {
dir = "desc";
switching = true;
}
}
}
sessionStorage.setItem('sortBy', n);
sessionStorage.setItem('sortByDir', dir);
}
function checkStrorage() {
var sortBy= sessionStorage.getItem('sortBy');
if (sortBy !== null) {
sortTable(parseInt(sortBy), sessionStorage.getItem('sortByDir'));
}
}
</script>
</body>
</html>
我正在使用来自 w3.js(https://www.w3schools.com/howto/howto_js_sort_table.asp) 的 table 分拣机。
另外，我已经使用 setTimeout 来每分钟刷新页面以更新数据。
我想保留刷新页面后的排序结果
我知道有一种方法是使用sessionStorage，但是不知道怎么用
谁能给我一些提示？
下面是 SortTable. We use the browser cookies to restore the last sort information, which are mainly the sorting column and direction. There is another example in W3school, from which I got the cookie handling (Cookies) 中示例的更新片段。由于跨源政策，下面的代码片段在网站上不起作用。当然，它也需要一些重构，但这是一个开始。
<!DOCTYPE html>
<html>
<head>
<title>Sort a HTML Table Alphabetically</title>
<style>
table {
border-spacing: 0;
width: 100%;
border: 1px solid #ddd;
}
th {
cursor: pointer;
}
th, td {
text-align: left;
padding: 16px;
}
tr:nth-child(even) {
background-color: #f2f2f2
}
</style>
</head>
<body onload="checkCookie();">
<p><strong>Click the headers to sort the table.</strong></p>
<p>The first time you click, the sorting direction is ascending (A to Z).</p>
<p>Click again, and the sorting direction will be descending (Z to A):</p>
<table id="myTable">
<tr>
<!--When a header is clicked, run the sortTable function, with a parameter, 0 for sorting by names, 1 for sorting by country:-->
<th onclick="sortTable(0)">Name</th>
<th onclick="sortTable(1)">Country</th>
</tr>
<tr>
<td>Berglunds snabbkop</td>
<td>Sweden</td>
</tr>
<tr>
<td>North/South</td>
<td>UK</td>
</tr>
<tr>
<td>Alfreds Futterkiste</td>
<td>Germany</td>
</tr>
<tr>
<td>Koniglich Essen</td>
<td>Germany</td>
</tr>
<tr>
<td>Magazzini Alimentari Riuniti</td>
<td>Italy</td>
</tr>
<tr>
<td>Paris specialites</td>
<td>France</td>
</tr>
<tr>
<td>Island Trading</td>
<td>UK</td>
</tr>
<tr>
<td>Laughing Bacchus Winecellars</td>
<td>Canada</td>
</tr>
</table>
<script>
function sortTable(n, dir) {
var table, rows, switching, i, x, y, shouldSwitch, dir, switchcount = 0;
table = document.getElementById("myTable");
switching = true;
//Set the sorting direction to ascending:
!dir && (dir = "asc");
/*Make a loop that will continue until
no switching has been done:*/
while (switching) {
//start by saying: no switching is done:
switching = false;
rows = table.getElementsByTagName("TR");
/*Loop through all table rows (except the
first, which contains table headers):*/
for (i = 1; i < (rows.length - 1); i++) {
//start by saying there should be no switching:
shouldSwitch = false;
/*Get the two elements you want to compare,
one from current row and one from the next:*/
x = rows[i].getElementsByTagName("TD")[n];
y = rows[i + 1].getElementsByTagName("TD")[n];
/*check if the two rows should switch place,
based on the direction, asc or desc:*/
if (dir == "asc") {
if (x.innerHTML.toLowerCase() > y.innerHTML.toLowerCase()) {
//if so, mark as a switch and break the loop:
shouldSwitch= true;
break;
}
} else if (dir == "desc") {
if (x.innerHTML.toLowerCase() < y.innerHTML.toLowerCase()) {
//if so, mark as a switch and break the loop:
shouldSwitch= true;
break;
}
}
}
if (shouldSwitch) {
/*If a switch has been marked, make the switch
and mark that a switch has been done:*/
rows[i].parentNode.insertBefore(rows[i + 1], rows[i]);
switching = true;
//Each time a switch is done, increase this count by 1:
switchcount ++;
} else {
/*If no switching has been done AND the direction is "asc",
set the direction to "desc" and run the while loop again.*/
if (switchcount == 0 && dir == "asc") {
dir = "desc";
switching = true;
}
}
}
setCookie("sortBy", n, 30);
setCookie("sortByDir", dir);
}
function setCookie(cname,cvalue,exdays) {
var d = new Date();
d.setTime(d.getTime() + (exdays*24*60*60*1000));
var expires = "expires=" + d.toGMTString();
document.cookie = cname + "=" + cvalue + ";" + expires + ";path=/";
}
function getCookie(cname) {
var name = cname + "=";
var decodedCookie = decodeURIComponent(document.cookie);
var ca = decodedCookie.split(';');
for(var i = 0; i < ca.length; i++) {
var c = ca[i];
while (c.charAt(0) == ' ') {
c = c.substring(1);
}
if (c.indexOf(name) == 0) {
return c.substring(name.length, c.length);
}
}
return "";
}
function checkCookie() {
var sortBy=getCookie("sortBy");
if (sortBy != "") {
sortTable(parseInt(sortBy), getCookie("sortByDir"));
}
}
</script>
</body>
</html>
编辑： 另一个使用 sessionStorage 的片段
<!DOCTYPE html>
<html>
<head>
<title>Sort a HTML Table Alphabetically</title>
<style>
table {
border-spacing: 0;
width: 100%;
border: 1px solid #ddd;
}
th {
cursor: pointer;
}
th, td {
text-align: left;
padding: 16px;
}
tr:nth-child(even) {
background-color: #f2f2f2
}
</style>
</head>
<body onload="checkStrorage();">
<p><strong>Click the headers to sort the table.</strong></p>
<p>The first time you click, the sorting direction is ascending (A to Z).</p>
<p>Click again, and the sorting direction will be descending (Z to A):</p>
<table id="myTable">
<tr>
<!--When a header is clicked, run the sortTable function, with a parameter, 0 for sorting by names, 1 for sorting by country:-->
<th onclick="sortTable(0)">Name</th>
<th onclick="sortTable(1)">Country</th>
</tr>
<tr>
<td>Berglunds snabbkop</td>
<td>Sweden</td>
</tr>
<tr>
<td>North/South</td>
<td>UK</td>
</tr>
<tr>
<td>Alfreds Futterkiste</td>
<td>Germany</td>
</tr>
<tr>
<td>Koniglich Essen</td>
<td>Germany</td>
</tr>
<tr>
<td>Magazzini Alimentari Riuniti</td>
<td>Italy</td>
</tr>
<tr>
<td>Paris specialites</td>
<td>France</td>
</tr>
<tr>
<td>Island Trading</td>
<td>UK</td>
</tr>
<tr>
<td>Laughing Bacchus Winecellars</td>
<td>Canada</td>
</tr>
</table>
<script>
function sortTable(n, dir) {
var table, rows, switching, i, x, y, shouldSwitch, dir, switchcount = 0;
table = document.getElementById("myTable");
switching = true;
//Set the sorting direction to ascending:
!dir && (dir = "asc");
/*Make a loop that will continue until
no switching has been done:*/
while (switching) {
//start by saying: no switching is done:
switching = false;
rows = table.getElementsByTagName("TR");
/*Loop through all table rows (except the
first, which contains table headers):*/
for (i = 1; i < (rows.length - 1); i++) {
//start by saying there should be no switching:
shouldSwitch = false;
/*Get the two elements you want to compare,
one from current row and one from the next:*/
x = rows[i].getElementsByTagName("TD")[n];
y = rows[i + 1].getElementsByTagName("TD")[n];
/*check if the two rows should switch place,
based on the direction, asc or desc:*/
if (dir == "asc") {
if (x.innerHTML.toLowerCase() > y.innerHTML.toLowerCase()) {
//if so, mark as a switch and break the loop:
shouldSwitch= true;
break;
}
} else if (dir == "desc") {
if (x.innerHTML.toLowerCase() < y.innerHTML.toLowerCase()) {
//if so, mark as a switch and break the loop:
shouldSwitch= true;
break;
}
}
}
if (shouldSwitch) {
/*If a switch has been marked, make the switch
and mark that a switch has been done:*/
rows[i].parentNode.insertBefore(rows[i + 1], rows[i]);
switching = true;
//Each time a switch is done, increase this count by 1:
switchcount ++;
} else {
/*If no switching has been done AND the direction is "asc",
set the direction to "desc" and run the while loop again.*/
if (switchcount == 0 && dir == "asc") {
dir = "desc";
switching = true;
}
}
}
sessionStorage.setItem('sortBy', n);
sessionStorage.setItem('sortByDir', dir);
}
function checkStrorage() {
var sortBy= sessionStorage.getItem('sortBy');
if (sortBy !== null) {
sortTable(parseInt(sortBy), sessionStorage.getItem('sortByDir'));
}
}
</script>
</body>
</html>