php – 从preg_match_all()突出显示主题字符串中的匹配结果

2024年1月2日 227次阅读

我试图用preg_match_all()返回的$matches数组突出显示主题字符串.让我从一个例子开始：

preg_match_all("/(.)/", "abc", $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER);

这将返回：

Array
(
    [0] => Array
        (
            [0] => Array
                (
                    [0] => a
                    [1] => 0
                )

            [1] => Array
                (
                    [0] => a
                    [1] => 0
                )

        )

    [1] => Array
        (
            [0] => Array
                (
                    [0] => b
                    [1] => 1
                )

            [1] => Array
                (
                    [0] => b
                    [1] => 1
                )

        )

    [2] => Array
        (
            [0] => Array
                (
                    [0] => c
                    [1] => 2
                )

            [1] => Array
                (
                    [0] => c
                    [1] => 2
                )

        )

)

在这种情况下,我想要做的是突出显示整体消耗的数据和每个反向引用.

输出应如下所示：

<span class="match0">
    <span class="match1">a</span>
</span>
<span class="match0">
    <span class="match1">b</span>
</span>
<span class="match0">
    <span class="match1">c</span>
</span>

另一个例子：

preg_match_all("/(abc)/", "abc", $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER);

应该返回：

<span class="match0"><span class="match1">abc</span></span>

我希望这很清楚.

我想强调整体消费数据并突出显示每个反向引用.

提前致谢.如果有任何不清楚的地方,请询问.

注意：它不能破坏html.正则表达式和输入字符串都是代码未知的并且是完全动态的.因此搜索字符串可以是html,匹配的数据可以包含类似html的文本,但不包含.

最佳答案 这似乎对我迄今为止所抛出的所有例子都是正确的.请注意,我已经从HTML-mangling部分中删除了抽象突出显示部分,以便在其他情况下重用：

<?php

/**
 * Runs a regex against a string, and return a version of that string with matches highlighted
 * the outermost match is marked with [0]...[/0], the first sub-group with [1]...[/1] etc
 *
 * @param string $regex Regular expression ready to be passed to preg_match_all
 * @param string $input
 * @return string
 */
function highlight_regex_matches($regex, $input)
{
    $matches = array();
    preg_match_all($regex, $input, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER);

    // Arrange matches into groups based on their starting and ending offsets
    $matches_by_position = array();
    foreach ( $matches as $sub_matches )
    {
            foreach ( $sub_matches as $match_group => $match_data )
            {
                    $start_position = $match_data[1];
                    $end_position = $start_position + strlen($match_data[0]);

                    $matches_by_position[$start_position]['START'][] = $match_group;

                    $matches_by_position[$end_position]['END'][] = $match_group;
            }
    }

    // Now proceed through that array, annotoating the original string
    // Note that we have to pass through BACKWARDS, or we break the offset information
    $output = $input;
    krsort($matches_by_position);
    foreach ( $matches_by_position as $position => $matches )
    {
            $insertion = '';

            // First, assemble any ENDING groups, nested highest-group first
            if ( is_array($matches['END']) )
            {
                    krsort($matches['END']);
                    foreach ( $matches['END'] as $ending_group )
                    {
                            $insertion .= "[/$ending_group]";
                    }
            }

            // Then, any STARTING groups, nested lowest-group first
            if ( is_array($matches['START']) )
            {
                    ksort($matches['START']);
                    foreach ( $matches['START'] as $starting_group )
                    {
                            $insertion .= "[$starting_group]";
                    }
            }

            // Insert into output
            $output = substr_replace($output, $insertion, $position, 0);
    }

    return $output;
}

/**
 * Given a regex and a string containing unescaped HTML, return a blob of HTML
 * with the original string escaped, and matches highlighted using <span> tags
 *
 * @param string $regex Regular expression ready to be passed to preg_match_all
 * @param string $input
 * @return string HTML ready to display :)
 */
function highlight_regex_as_html($regex, $raw_html)
{
    // Add the (deliberately non-HTML) highlight tokens
    $highlighted = highlight_regex_matches($regex, $raw_html);

    // Escape the HTML from the input
    $highlighted = htmlspecialchars($highlighted);

    // Substitute the match tokens with desired HTML
    $highlighted = preg_replace('#\[([0-9]+)\]#', '<span class="match\\1">', $highlighted);
    $highlighted = preg_replace('#\[/([0-9]+)\]#', '</span>', $highlighted);

    return $highlighted;
}

注意：正如hakra在聊天中向我指出的那样,如果正则表达式中的一个子组可以在一个整体匹配中多次出现(例如’/ a(b | c)/’),preg_match_all只会告诉你最后一个那些匹配 – 所以highlight_regex_matches(‘/ a(b | c)/’,’abc’)返回'[0] ab [1] c [/ 1] [/ 0]’不'[0] a [1] b [/ 1] [1] c [/ 1] [/ 0]’正如您所期望/想要的那样.之外的所有匹配组仍然可以正常工作,因此highlight_regex_matches(‘/ a((b | c))/’,’abc’)给出'[0] a [1] b [2] c [/ 2] [ / 1] [/ 0]’这仍然是正则表达式如何匹配的一个很好的指示.

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