用< A>替换非HTML链接标签 [英] Replace non-html links with <A> tags

问题描述

我有一个代码块，它将采用如下所示的文本块：

I have a block of code that will take a block of text like the following:

示例文本示例文本 http://www.google.com 示例文本

使用 preg_replace_callback 方法和以下正则表达式：

Using the preg_replace_callback method and the following regular expression:

preg_replace_callback('/http:\/\/([,\%\w.\-_\/\?\=\+\&\~\#\$]+)/',
    create_function(
        '$matches',
        '$url = $matches[1]; 
        $anchorText = ( strlen($url) > 35 ? substr($url, 0, 35).\'...\' : $url); 
        return \'<a href="http://\'. $url .\'">\'. $anchorText .\'</a>\';'),
    $str);

将示例文本转换为：

示例文本示例文本< a href =http://www.google.com> http://www.google.com < / a>示例文本

Sample text sample text < a href="http://www.google.com">http://www.google.com< /a> sample text

我现在的问题是我们引入了一个富文本编辑器，可以在发送到脚本之前创建链接。我需要更新这段代码，以便它会忽略标签内已有的任何URL。

My problem now is that we have introduced a rich text editor that can create links before being sent to the script. I need to update this piece of code so that it will ignore any URLs that are already inside an tag.

推荐答案

添加代码到捕获开始锚标记的模式的开头，然后在捕获到的东西时不执行回调代码：

Add code to the beginning of the pattern to capture an opening anchor tag, and then do not perform the callback code when it has captured something:

/(<a[^>]*>)?http:\/\/([,\%\w.\-_\/\?\=\+\&\~\#\$]+)/

然后你需要在你的lamda函数中添加一个if来查看$ matches中是否有任何内容[1]（不要忘记增加你的捕获量）

You will then need to add an if to your lamda function to see if there is anything in $matches[1] (Don't forget to increment your captures as well)

你不能使用由于捕获不是一个固定的长度，所以负面看待断言，但你可以使用一个负向前看断言来结束标记，这样它就会丢掉整个匹配：

You cannot use a negative look behind assertion here as the capture is not a fixed length, but you could use a negative look ahead assertion for the closing tag so it drops the entire match:

/(<a[^>]*>)?http:\/\/([,\%\w.\-_\/\?\=\+\&\~\#\$]+)(?!<\/a>)/

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