deepLearn/cookie模拟localStorage.html at master · wangliang1124/deepLearn · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>localStorage</title>
</head>

<body>

</body>
<script>
    function setCookie(key, value = '', days = 0) {
        if (!key) return
        let date = new Date()
        date.setTime(date.getTime() + days * 24 * 60 * 60 * 1000); // 设置过期时间为 days 天之后
        document.cookie = key + "=" + encodeURIComponent(value) + ";expires=" + date.toUTCString();
    }

    function getCookie(key) {
        let value = ''
        let cookie = document.cookie + ";"
        let queryString = key + "="
        let start = cookie.indexOf(queryString)
        if (start > -1) {
            start += queryString.length
            let end = cookie.indexOf(";", start)
            value = decodeURIComponent(cookie.substring(start, end));
        }
        // return getCookies()[key]
        return value
    }

    function getCookies() {
        let result = {}
        if (!document.cookie) return result
        document.cookie.split(';').forEach((item) => {
            if (item.indexOf('=') > -1) {
                let [key, value] = item.split('=')
                result[key.trim()] = decodeURIComponent(value.trim());
            }
        })
        return result
    }

    window.localStorage = new LocalStorage()

    function LocalStorage() {
        const cookies = getCookies()
        this.length = Object.keys(cookies).length
        for (let [key, value] of Object.entries(cookies)) {
            this[key] = value
        }
    }

    LocalStorage.prototype = function () {
        function getItem(key) {
            return getCookie(key);
        }

        function setItem(key, value, days) {
            this[key] = value
            this.length++
            setCookie(key, value, days)
        }

        function removeItem(key) {
            this.length--
            delete this[key]
            setItem(key, '', -1);
        }

        function clear() {
            const cookies = getCookies();
            for (let key of Object.keys(cookies)) {
                removeItem(key);
            }
            this.length = 0
        }

        return {
            constructor: LocalStorage,
            getItem,
            setItem,
            removeItem,
            clear,
        }
    }()

    console.log(document.cookie, window.localStorage)
</script>

</html>