Question

我正在尝试编写一个脚本，该脚本将执行以下操作：

从文件或数据库中读取内容
从内容中提取所有锚标记
扫描所有链接并保留允许的链接，例如链接到社交网络，搜索引擎或权威域，并删除其余内容，同时保留其内容（锚文本）。

示例内容：

<a rel="nofollow" href="http://www.test.com/tyest">test1</a>
<a href="http://google.com">google</a>
<a title="This is just a check" href="http://www.check.com">check</a>
<a rel="nofollow" href="http://www.ip.com">http://www.ip.com</a>

允许的域名：

google.com
msn.com
ip.com

期望的输出：

test1
<a href="http://google.com">google</a>
check
<a rel="nofollow" href="http://www.ip.com">http://www.ip.com</a>

限制：

锚标记不会遵循任何特定规则，并且可以包含rel，title，descrition属性，也可以包含任何顺序。
锚文本本身也可以是一个链接，例如：http://google.com即使不允许链接也应该保留。

我完成了我的作业并尝试编写一个简单的裸级脚本，以使用不同的正则表达式以及在线提供的帮助开始初始工作，但没有成功。这是我的代码：

// sample input
$comment = '<p><a rel="nofollow" href="http://www.1google.com/tyest">test with no http</a></p>
                <p><a rel="nofollow" href="http://google.com">just a domain name</a></p>
                <p><a rel="nofollow" href="http://www.g1gle.com">check</a></p>
                <p><a rel="nofollow" href="http://www.ip.com">http://www.ip.com</a></p>
                <p><a rel="nofollow" href="http://osamashabrez.com">http://testx.osamashabrez.com</a></p>
                <p><a rel="nofollow" href="http://www.subchalega.com">http://www.subchalega.com</a></p>
                <p><a rel="nofollow" href="http://www.letscheck.com">http://www.letscheck.com</a></p>
                <p><a rel="nofollow" href="http://www.google.com/osama/here/">http://www.google.com</a></p>
                <p><a rel="nofollow" description="testing" title="google" href="http://www.google.com/last/">laaaaaaaa</a></p><h1>Header one</h1>
                <p><a rel="nofollow" href="http://domain1.com">http://testx.osamashabrez.com</a></p>';

// add http to the domain name if not already present
function addhttp($url) {
    if (!preg_match('~^(?:f|ht)tps?://~i', $url)) {
        $url = 'http://' . $url;
    }
    return $url;
}

// removed deep links to match with the allowed URLS 
function removeDeepLinks($url) {
    $pos = strrpos ( $url, '.com' );
    if ( $pos !== false )
        return substr( $url, 6, $pos-2 );
    return $url;
}
// allowed domains fetched from the db
$domains = "http://osamashabrez.com\rhttp://google.com\rwordpress.org\rabc.com";
$domains = preg_split( "~\r~", $domains, -1, PREG_SPLIT_NO_EMPTY );
// adding http if not already present
// will be done one when data will be inserted
foreach ( $domains as $key => $domain ) { $domains[$key] = addhttp($domain); }
// remove this and sky will fall on your head :D
sort( $domains );
print_r ( $domains );
// regex to extract href="xyz.com" link as we can not use any other option
// due to the uncertainity of data passed to this script
$regex = '/(href=".*?")/is';
if ($c=preg_match_all ($regex, $comment, $matches)) {
    $matches = $matches[1];
    foreach ( $matches as $key => $url ) {
        // remove deep links for matching
        $matches[$key] = removeDeepLinks($url);
    }
    print_r($matches);
    foreach( $matches as $key => $url ) {
        // if domain is not allowed
        if ( !array_search( $url, $domains ) ) {
            // find position of URL
            $pos_url     = strrpos( $comment, $url );
            // fint the starting position of anchor tag
            $pos_a_start = strrpos(substr($comment, 0, $pos_url), '<a ');
            // fint the end
            $pos_a_end   = strpos($comment, '</a>',$pos_url);
            // extract the whole anchor tag
            $anchor_tag  = substr($comment, $pos_a_start, $pos_a_end - $pos_a_start + 4);
            echo "URL:\t" .$url . "\r";
            echo "Anchor Tag:\t{$anchor_tag}\r";
            echo "POS START :: END:\t{$pos_a_start}::{$pos_a_end}\r";


            // something weired goes where commenting this line works but only the opening
            // tags are removed from the text
            // the code does work with some data inputs and does not work with a few others
            $comment = substr($comment, 0, $pos_a_end) . substr($comment, $pos_a_end+4);
            // removing opening tags
            $opening_tag = substr( $anchor_tag, 0, strpos($anchor_tag, '>') +1 );
            $comment = str_replace($opening_tag, '', $comment);
        }
    }
}
echo $comment;

上面的代码正在使用一些数据输入和其他的中断，我想得到一些帮助，工作代码示例或我提供的代码的审查。还要提一下是否有更好的方法来完成工作。任何帮助将受到高度赞赏。

由于

Answer 1

DOM解析器更适合此任务。

有很多选择，包括：

以下是使用QueryPath的示例：

$qp = qp($html)
foreach ($qp->find('a') as $link) {
    $href = $link->attr('href');
    // Get the host domain
    $host = parse_url($href, PHP_URL_HOST);
    // Check our allowed hosts
    if (!in_array($host, $allowedHosts) {
        // Replace the links HTML with just its text
        $link->html($link->text());
    }
}
// Echo our result
echo $query->top()->html();

（未经过测试，但应进行一些修改。）

提取并删除不允许的锚标记

1 个答案: