这两天队友在做一个uni-app项目，交接的时候发现他是用浏览器调试的，而我写的代码用了log4js，浏览器不能使用这个npm包，于是我决定给他写一个浏览器彩色日志打印器。
核心原理
是利用浏览器的console.log方法，通过css样式来实现彩色打印。
eg：
console.log(
"%c%s",
"color:#17a8cd;background-color:#d4f5ff;",
"这是一条debug日志"
);
代码
可以直接复制，粘贴到浏览器控制台中
class Logger {
/**
* @param {string} level
*/
set level(level) {
if (["debug", "info", "warn", "error"].indexOf(level) == -1) {
throw new Error("level must be debug | info | warn | error");
}
this._level = level;
this._levelnum = ["debug", "info", "warn", "error"].indexOf(level);
}
constructor(name = "log", level = "debug") {
this._level = "debug"; // debug | info | warn | error
this._levelnum = 0;
this._name = name;
this.level = level;
this.color = this.stringToColor(name);
}
debug(...msg) {
if (this._levelnum > 0)
return;
let css = "color:#17a8cd;background-color:#d4f5ff;";
console.log("%c%s", css, `[${this.getTimestamp()}] [DEBUG] [${this._name}] - `, ...msg);
}
info(...msg) {
if (this._levelnum > 1)
return;
let css = "color:#008a15;background-color:#e6ffe9;";
console.log("%c%s", css, `[${this.getTimestamp()}] [INFO] [${this._name}] - `, ...msg);
}
warn(...msg) {
if (this._levelnum > 2)
return;
let css = "color:#e88f21;background-color:#fffbe6;";
console.log("%c%s", css, `[${this.getTimestamp()}] [WARN] [${this._name}] - `, ...msg);
}
error(...msg) {
if (this._levelnum > 3)
return;
let css = "color:#ff0000;background-color:#fff0f0;";
console.log("%c%s", css, `[${this.getTimestamp()}] [ERROR] [${this._name}] - `, ...msg);
}
getTimestamp() {
return new Date(new Date().valueOf() + 1000 * 60 * 60 * 8).toISOString();
}
log(...msg) {
console.log("%c%s", `color:${this.color};`, `[${this.getTimestamp()}] [LOG] [${this._name}] - `, ...msg);
}
// 将任意字符串转换为颜色值
stringToColor(str) {
var hash = 0;
for (var i = 0; i < str.length; i++) {
hash = str.charCodeAt(i) + ((hash << 5) - hash);
}
var color = '#';
for (var i = 0; i < 3; i++) {
var value = (hash >> (i * 8)) & 0xFF;
color += ('00' + value.toString(16)).substr(-2);
}
return color;
}
}
have a try
你可以按 F12 打开浏览器控制台试一下
let log = new Logger("test", "debug");
log.debug("这是一条debug日志");
log.info("这是一条info日志");
log.warn("这是一条warn日志");
log.error("这是一条error日志");
log.log("这是一条log日志，颜色是根据名称自动生成的");
更新
2023-9-10
将项目发布为npm包，项目地址：opchatjs-webLogger
