使用yuicompressor进行条件补偿

Question

I have the following javascript snippet to detect if a browser is IE 6 - 11: 我有以下javascript代码段来检测浏览器是否为IE 6-11：

var isIE = /*@cc_on!@*/false || !!document.documentMode;

I copied this from an excellent answer on SO here . 我从这里的一个很好的答案中复制了这一点。 However when i go to minify the script with yuicompressor, it breaks it with the following errors: 但是，当我使用yuicompressor缩小脚本时，它会因以下错误而中断：

[ERROR] in utils.js
  349:33:missing ; before statement
[ERROR] in utils.js
  1:0:Compilation produced 1 syntax errors.
org.mozilla.javascript.EvaluatorException: Compilation produced 1 syntax errors.
    at com.yahoo.platform.yui.compressor.YUICompressor$1.runtimeError(YUICompressor.java:172)
    at org.mozilla.javascript.Parser.parse(Parser.java:396)
    at org.mozilla.javascript.Parser.parse(Parser.java:340)
    at com.yahoo.platform.yui.compressor.JavaScriptCompressor.parse(JavaScriptCompressor.java:315)
    at com.yahoo.platform.yui.compressor.JavaScriptCompressor.<init>(JavaScriptCompressor.java:536)
    at com.yahoo.platform.yui.compressor.YUICompressor.main(YUICompressor.java:147)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.yahoo.platform.yui.compressor.Bootstrap.main(Bootstrap.java:21)

I read up on yuicompressor and found that it can preserve javascript block comments when they are like so: /*! comment */ 我阅读了yuicompressor ，发现它可以保留javascript块注释，例如： /*! comment */ /*! comment */ , however changing the snippet to the following does not fix it: /*! comment */ ，但是将代码段更改为以下内容并不能解决该问题：

var isIE = /*!@cc_on!@*/false || !!document.documentMode;

The error messages are still the same. 错误消息仍然相同。 And I also wonder if this would break the conditional compilation? 而且我还想知道这是否会破坏条件编译？ All the examples of conditional compilation open a comment like so /*@ and close it like so: @*/ which makes me think that conditional compilation only works with this combination of comment symbols. 条件编译的所有示例都以/*@这样的方式打开注释，并以如下方式将其关闭： @*/ ，这使我认为条件编译仅适用于注释符号的这种组合。

Does anybody know how I can get this working? 有人知道我该如何工作吗？ Other solutions which maintain the same functionality and pass correctly through yuicompressor are also acceptable as an answer here. 保持相同功能并正确通过yuicompressor的其他解决方案也可以作为答案。

Answer 1

An alternative method to detect IE is to use a global variable for IE <= 9. This will will pass yuicompressor validation: 检测IE的另一种方法是对IE <= 9使用全局变量。这将通过yuicompressor验证：

<html>
<body>
<!--[if IE]><script>isIE9OrLess = true;</script><![endif]-->
<script>
var isIE9OrLess = (typeof isIE9OrLess !== 'undefined');
document.write('are we in ie <= 9? ' + (isIE9OrLess ? 'yes' : 'no') + '<br>');
// detect ie > 9 using document.documentMode
var isIE = isIE9OrLess || !!document.documentMode;
document.write('are we in ie at all? ' + (isIE ? 'yes' : 'no'));
</script>
</body>
</html>

Its not ideal though since it only bypasses the problem without actually solving it. 它不是理想的，因为它仅绕过问题而没有实际解决。

使用yuicompressor进行条件补偿

问题描述

1 个解决方案

解决方案1
0 2018-08-24 01:50:44

使用yuicompressor进行条件补偿

问题描述

1 个解决方案

解决方案1 0 2018-08-24 01:50:44

解决方案1
0 2018-08-24 01:50:44