A detailed introduction to using web storage in html5-H5 Tutorial-php.cn

Home

Web Front-end

H5 Tutorial

A detailed introduction to using web storage in html5

黄舟

Mar 15, 2017 pm 04:00 PM

1) Use local storage (localStorage):

Access the local storage function through global propertylocalStorage, and will return a Storage Object , which is used to hold string pairs in the form of key/value.

Members of the Storage object:

clear()——Remove the saved key/value pair;

getItem(<key>)——Get the value associated with the specified key;

key(< ;index>)——Get the key of the specified index;

length——Return the number of saved key/value pairs;

removeItem()——Remove the key/value pair corresponding to the specified key;

setItem( ,) - Add a new key/value pair and update its value if the key is already used;

[ ]——Use the access form of array to obtain the value associated with the specified key;

Listen to the storage event:

When a document modifies local storage, the storage event will be triggered, and the assigned object is a StorageEvent object, whose members are:

key——return occurs Changed key;

oldValue——Returns the old value associated with this key;

newValue——Returns the new value associated with this key;

url——Returns the URL of the changed document;

storageArea——Returns the changed Storage object;

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>上海远地资产管理有限公司</title>
    <meta name="author" content="jason"/>
    <meta name="description" content="上海远地资产管理有限公司（简称：远地资产），是一家专业的互联网金融服务平台."/>
    <link rel="shortcut icon" href="images/favicon.ico" type="image/x-icon"/>
    <style type="text/css">
        body > *{
            float:left;
        }
        table{
            border-collapse: collapse;
            margin-left: 50px;
        }
        th,td{
            padding: 4px;
        }
        th{
            text-align: right;
        }
        input{
            border:thin solid black;
            padding: 2px;
        }
        label{
            min-width: 50px;
            display: inline-block;
            text-align: right;
        }
        #countmsg,#buttons{
            margin-left: 50px;
            margin-top:5px;
            margin-bottom: 5px;
        }
    </style>
</head>
<body>
<p>
    <p>
        <label>Key:</label>
        <input id="key" placeholder="Enter Key">
    </p>
    <p>
        <label>Value:</label>
        <input id="value" placeholder="Enter Value">
    </p>
    <p id="buttons">
        <button id="add">Add</button>
        <button id="clear">Clear</button>
    </p>
    <p id="countmsg">There are <span id="count"></span> items</p>
</p>
<table id="data" border="1">
    <tr>
        <th>Item Count:</th><td>-</td>
    </tr>
</table>
<script>
    displayData();
    var buttons=document.getElementsByTagName("button");
    for(var i=0;i<buttons.length;i++){
        buttons[i].onclick=handleButtonPress;
    }
    function handleButtonPress(e){
        switch(e.target.id){
            case &#39;add&#39;:
            var key=document.getElementById("key").value;
            var value=document.getElementById("value").value;
                localStorage.setItem(key,value);
                break;
            case &#39;clear&#39;:
                localStorage.clear();
                break;
        }
        displayData();
    }
    function displayData(){
        var tableElem=document.getElementById("data");
        tableElem.innerHTML="";
        var itemCount=localStorage.length;
        document.getElementById("count").innerHTML=itemCount;
        for(var i=0;i<itemCount;i++){
            var key=localStorage.key(i);
            var val=localStorage[key];
            tableElem.innerHTML+="<tr><th>"+key+":</th><td>"+val+"</td></tr>";
        }
    }
</script>
</body>
</html>

Copy after login

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
    <style type="text/css">
        table{
            border-collapse: collapse;
            margin-left: 50px;
        }
        th,td{
            padding: 4px;
        }
    </style>
</head>
<body>
<table id="data" border="1">
    <tr>
        <th>key</th>
        <th>oldValue</th>
        <th>newValue</th>
        <th>url</th>
        <th>storageArea</th>
    </tr>
</table>
<script>
    var tableElem=document.getElementById("data");
    window.onstorage=handleStorage;
    function handleStorage(e){
        var row="<tr>";
        row+="<td>"+ e.key+"</td>";
        row+="<td>"+ e.oldValue+"</td>";
        row+="<td>"+ e.newValue+"</td>";
        row+="<td>"+ e.url+"</td>";
        row+="<td>"+ (e.storageArea == localStorage)+"</td></tr>";
        tableElem.innerHTML+=row;
    }

</script>
</body>
</html>

Copy after login

2) Use session storage (sessionStorage)

Session storage works very close to local storage , the difference is that the data is private to each browser context and is removed when the document is closed.

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>上海远地资产管理有限公司</title>
    <meta name="author" content="jason"/>
    <meta name="description" content="上海远地资产管理有限公司（简称：远地资产），是一家专业的互联网金融服务平台."/>
    <link rel="shortcut icon" href="images/favicon.ico" type="image/x-icon"/>
    <style type="text/css">
        body > *{
            float:left;
        }
        table{
            border-collapse: collapse;
            margin-left: 50px;
        }
        th,td{
            padding: 4px;
        }
        th{
            text-align: right;
        }
        input{
            border:thin solid black;
            padding: 2px;
        }
        label{
            min-width: 50px;
            display: inline-block;
            text-align: right;
        }
        #countmsg,#buttons {
            margin-left: 50px;
            margin-top: 5px;
            margin-bottom: 5px;
        }
    </style>
</head>
<body>
<p>
    <p>
        <label>Key:</label>
        <input id="key" placeholder="Enter Key">
    </p>
    <p>
        <label>Value:</label>
        <input id="value" placeholder="Enter Value">
    </p>
    <p id="buttons">
        <button id="add">Add</button>
        <button id="clear">Clear</button>
    </p>
    <p id="countmsg">There are <span id="count"></span> items</p>
</p>
<table id="data" border="1">
    <tr>
        <th>Item Count:</th><td>-</td>
    </tr>
</table>
<script>
    displayData();
    var buttons=document.getElementsByTagName("button");
    for(var i=0;i<buttons.length;i++){
        buttons[i].onclick=handleButtonPress;
    }
    function handleButtonPress(e){
        switch(e.target.id){
            case &#39;add&#39;:
            var key=document.getElementById("key").value;
            var value=document.getElementById("value").value;
                sessionStorage.setItem(key,value);
                break;
            case &#39;clear&#39;:
                sessionStorage.clear();
                break;
        }
        displayData();
    }
    function displayData(){
        var tableElem=document.getElementById("data");
        tableElem.innerHTML="";
        var itemCount=sessionStorage.length;
        document.getElementById("count").innerHTML=itemCount;
        for(var i=0;i<itemCount;i++){
            var key=sessionStorage.key(i);
            var val=sessionStorage[key];
            tableElem.innerHTML+="<tr><th>"+key+":</th><td>"+val+"</td></tr>";
        }
    }
</script>
</body>
</html>

Copy after login

The above is the detailed content of A detailed introduction to using web storage in html5. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn