Javascript 在页面内的 div 中显示控制台错误和警报

Showing console errors and alerts in a div inside the page

提问by Mohsen

I'm building a debugging tool for my web app and I need to show console errors in a div. I know I can use my own made console like object and use it, but for future use I need to send all console errors to window. Actually I want to catch console events.

我正在为我的 Web 应用程序构建一个调试工具，我需要在 div 中显示控制台错误。我知道我可以像对象一样使用我自己制作的控制台并使用它，但是为了将来使用，我需要将所有控制台错误发送到 window.console 。其实我想捕捉控制台事件。

回答by jzilla

To keep the console working:

要保持控制台正常工作：

if (typeof console  != "undefined") 
    if (typeof console.log != 'undefined')
        console.olog = console.log;
    else
        console.olog = function() {};

console.log = function(message) {
    console.olog(message);
    $('#debugDiv').append('<p>' + message + '</p>');
};
console.error = console.debug = console.info =  console.log

回答by MST

Here's a way using closure, containing the old console log function in the scope of the new one.

这是一种使用闭包的方法，在新的范围内包含旧的控制台日志功能。

console.log = (function (old_function, div_log) { 
    return function (text) {
        old_function(text);
        div_log.value += text;
    };
} (console.log.bind(console), document.getElementById("error-log")));

回答by Micah Henning

Else, if you were concerned at keeping log, warnand errorseparate from one another, you could do something like this (adapted from MST's answer):

否则，如果您担心保持log，warn并且error彼此分开，您可以做这样的事情（改编自 MST 的回答）：

var log = document.querySelector('#log');

['log','warn','error'].forEach(function (verb) {
    console[verb] = (function (method, verb, log) {
        return function (text) {
            method(text);
            // handle distinguishing between methods any way you'd like
            var msg = document.createElement('code');
            msg.classList.add(verb);
            msg.textContent = verb + ': ' + text;
            log.appendChild(msg);
        };
    })(console[verb].bind(console), verb, log);
});

where #logis your HTML element. The variable verbis one of 'log', 'warn', or 'error'. You can then use CSS to style the text in a distinguishable way. Note that a lot of this code isn't compatible with old versions of IE.

#log你的 HTML 元素在哪里。变量verb是一个'log'，'warn'或'error'。然后，您可以使用 CSS 以可区分的方式设置文本样式。请注意，此代码中有很多与旧版本的 IE 不兼容。

回答by Peter Lyons

How about something as simple as:

像这样简单的事情怎么样：

console.log = function(message) {$('#debugDiv').append('<p>' + message + '</p>');};
console.error = console.debug = console.info =  console.log

回答by jox

None of the answers here consider console messages that get passed multiple parameters. E.g. console.log("Error:", "error details")).

这里的答案都没有考虑传递多个参数的控制台消息。例如console.log("Error:", "error details")）。

The function that replaces the default log function better regards all function arguments (e.g. by using the argumentsobject). Here is an example:

替换默认日志函数的函数更好地考虑所有函数参数（例如，通过使用arguments对象）。下面是一个例子：

console.log = function() {
  log.textContent += Array.prototype.slice.call(arguments).join(' ');
}

(The Array.prototype.slice.call(...)simply converts the argumentsobject to an array, so it can be concatenated easily with join().)

（Array.prototype.slice.call(...)简单地将arguments对象转换为数组，因此可以轻松地将其与 连接join()。）

When the original log should be kept working as well:

当原始日志也应该保持工作时：

console.log = (function (old_log, log) { 
    return function () {
        log.textContent += Array.prototype.slice.call(arguments).join(' ');
        old_log.apply(console, arguments);
    };
} (console.log.bind(console), document.querySelector('#log')));

A complete solution:

一个完整的解决方案：

var log = document.querySelector('#log');
['log','debug','info','warn','error'].forEach(function (verb) {
    console[verb] = (function (method, verb, log) {
        return function () {
            method.apply(console, arguments);
            var msg = document.createElement('div');
            msg.classList.add(verb);
            msg.textContent = verb + ': ' + Array.prototype.slice.call(arguments).join(' ');
            log.appendChild(msg);
        };
    })(console[verb], verb, log);
});

(An example of a framework that emits messages with multiple parameters is Video.js. But there is certainly many others.)

（发出带有多个参数的消息的框架的一个例子是 Video.js。但肯定还有很多其他的。）

Edit:Another use of multiple parameters is the formatting capabilities of the console (e.g. console.log("Status code: %d", code).

编辑：多个参数的另一个用途是控制台的格式化功能（例如console.log("Status code: %d", code).

回答by Optimaz ID

<!DOCTYPE html>
<html>
<head>
    <title>Page Title</title>
</head>
<body>
    <div id="logger" class="web_console"></div>

    <script type="text/javascript">

        // Overriding console object
        var console = {};

        // Getting div to insert logs
        var logger = document.getElementById("logger");

        // Adding log method from our console object
        console.log = function(text)
        {
            var element = document.createElement("div");
            var txt = document.createTextNode(text);

            element.appendChild(txt);
            logger.appendChild(element);
        }

        // testing
        console.log("Hello World...");
        console.log("WOW");

        /**
            console.log prints the message in the page instead browser console, useful to programming and debugging JS using a Android phone

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

回答by Jimmy Recard

I created a zero-dependency npmmodulefor this case: console-events(surely if you're okay to use nodejs :P)

我为这种情况创建了一个零依赖npm模块：（console-events当然，如果你可以使用 nodejs :P）

You can add event listener like that:

您可以像这样添加事件侦听器：

const { console } = require('console-events');

console.addEventListener('log', (e) => {
   e.preventDefault(); //if you need to prevent normal behaviour e.g. output to devtools console
   $('#debugDiv').append('<p>' + message + '</p>');
})