知识点---前端处理支持emoji表情

<!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>前端处理支持emoji表情</title>
</head> <body>
<h1>测试</h1>
<textarea rows="10" cols="40" id="text"></textarea>
<button type="" id="enbtn">编码</button>
<button type="" id="debtn">解码</button> <h2>结果</h2>
<div id="dv"></div>
</body>
</html> <script>
/**
*
* Base64 encode / decode
*
**/
var Base64 = { // private property
_keyStr: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=", // public method for encoding
encode: function (input) {
var output = "";
var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
var i = 0; input = Base64._utf8_encode(input); while (i < input.length) { chr1 = input.charCodeAt(i++);
chr2 = input.charCodeAt(i++);
chr3 = input.charCodeAt(i++); enc1 = chr1 >> 2;
enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
enc4 = chr3 & 63; if (isNaN(chr2)) {
enc3 = enc4 = 64;
} else if (isNaN(chr3)) {
enc4 = 64;
} output = output +
this._keyStr.charAt(enc1) + this._keyStr.charAt(enc2) +
this._keyStr.charAt(enc3) + this._keyStr.charAt(enc4); } return output;
}, // public method for decoding
decode: function (input) {
var output = "";
var chr1, chr2, chr3;
var enc1, enc2, enc3, enc4;
var i = 0; input = input.replace(/[^A-Za-z0-9\+\/\=]/g, ""); while (i < input.length) { enc1 = this._keyStr.indexOf(input.charAt(i++));
enc2 = this._keyStr.indexOf(input.charAt(i++));
enc3 = this._keyStr.indexOf(input.charAt(i++));
enc4 = this._keyStr.indexOf(input.charAt(i++)); chr1 = (enc1 << 2) | (enc2 >> 4);
chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
chr3 = ((enc3 & 3) << 6) | enc4; output = output + String.fromCharCode(chr1); if (enc3 != 64) {
output = output + String.fromCharCode(chr2);
}
if (enc4 != 64) {
output = output + String.fromCharCode(chr3);
} } output = Base64._utf8_decode(output); return output; }, // private method for UTF-8 encoding
_utf8_encode: function (string) {
string = string.replace(/\r\n/g, "\n");
var utftext = ""; for (var n = 0; n < string.length; n++) { var c = string.charCodeAt(n); if (c < 128) {
utftext += String.fromCharCode(c);
}
else if ((c > 127) && (c < 2048)) {
utftext += String.fromCharCode((c >> 6) | 192);
utftext += String.fromCharCode((c & 63) | 128);
}
else {
utftext += String.fromCharCode((c >> 12) | 224);
utftext += String.fromCharCode(((c >> 6) & 63) | 128);
utftext += String.fromCharCode((c & 63) | 128);
} } return utftext;
}, // private method for UTF-8 decoding
_utf8_decode: function (utftext) {
var string = "";
var i = 0;
var c = c1 = c2 = 0; while (i < utftext.length) { c = utftext.charCodeAt(i); if (c < 128) {
string += String.fromCharCode(c);
i++;
}
else if ((c > 191) && (c < 224)) {
c2 = utftext.charCodeAt(i + 1);
string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
i += 2;
}
else {
c2 = utftext.charCodeAt(i + 1);
c3 = utftext.charCodeAt(i + 2);
string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
i += 3;
} } return string;
} } //编码
document.getElementById('enbtn').onclick = encodeFn; function encodeFn() {
// 获取 value
var enval = document.getElementById('text').value; // 获取 value 中所有表情
var reg = enval.match(/[\uD83C|\uD83D|\uD83E][\uDC00-\uDFFF][\u200D|\uFE0F]|[\uD83C|\uD83D|\uD83E][\uDC00-\uDFFF]|[0-9|*|#]\uFE0F\u20E3|[0-9|#]\u20E3|[\u203C-\u3299]\uFE0F\u200D|[\u203C-\u3299]\uFE0F|[\u2122-\u2B55]|\u303D|[\A9|\AE]\u3030|\uA9|\uAE|\u3030/ig);
console.log(reg) // 将所有表情转成 base 64
var emojiBaseArr = reg.map(function (v) {
return '[' + Base64.encode(v) + ']'
})
console.log(emojiBaseArr); // 替换文本中所有表情
for (var i = 0; i < emojiBaseArr.length; i++) { // 相当于每次替换字符串中的第一个
var str = enval.replace(/[\uD83C|\uD83D|\uD83E][\uDC00-\uDFFF][\u200D|\uFE0F]|[\uD83C|\uD83D|\uD83E][\uDC00-\uDFFF]|[0-9|*|#]\uFE0F\u20E3|[0-9|#]\u20E3|[\u203C-\u3299]\uFE0F\u200D|[\u203C-\u3299]\uFE0F|[\u2122-\u2B55]|\u303D|[\A9|\AE]\u3030|\uA9|\uAE|\u3030/, emojiBaseArr[i]); // 将替换后的值重新赋值给 enval
enval = str;
}
console.log(enval); return enval;
} //解码
document.getElementById('debtn').onclick = function () { // 前端做了处理 后端不需要做任何操作,只需要原封不动的返回来即可 ( 假设获取后台返回的值 )
var deval = encodeFn()
console.log(deval); // 正则获取所有中括号中长度为8位的字符(包括中括号)
var res = deval.match(/\[[0-9a-zA-Z]{8}\]|\[[0-9a-zA-Z\+]{8}|\[[0-9a-zA-Z\+\/]{8}/g);
console.log(res); // 数组中的元素两边的中括号去掉,得到新的数组
var arr = res.map(function (v) {
return v.substr(1, 8)
})
console.log(arr); // 将新数组中的每个元素解码,得到新的数组
var deArr = arr.map(function (v) {
return Base64.decode(v);
})
console.log(deArr); // 将解码后的元素和文本中正则匹配到的一一替换
for (var i = 0; i < deArr.length; i++) {
var decode = deval.replace(/\[[0-9a-zA-Z]{8}\]|\[[0-9a-zA-Z\+]{8}\]|\[[0-9a-zA-Z\+\/]{8}/, deArr[i]);
deval = decode;
}
console.log(deval); // 渲染
document.getElementById('dv').innerHTML = deval
} </script>
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