按给定顺序突出显示多个搜索项

Question

已经看到了简单的preg_replace (甚至仅仅是str_replace)在搜索单词数组中添加<span class="highlight">的例子。但是，很多搜索查询都会按以下顺序搜索：

搜索：blue shoes

MySQL查询：SELECT * FROM my_table WHERE title LIKE '%blue%shoes%'

比赛：

MATCH --“别踩我的blue绒面shoes”

NO MATCH -“.他的漂亮鞋子和他的婴儿蓝调.”(关键字的顺序不对)

MATCH --“蓝天下的blue shoes”(第二个“蓝色”不应突出显示)

MATCH -“. blue笔记本.她的shoes扔了蓝色的塑料马蹄铁.”

因此，SERP应该以同样的方式突出显示匹配。是否有一种REGEX方法可以按照顺序使用n个搜索项来完成这一任务？还是需要用PHP循环来处理呢？

不正确的尝试：

foreach ( ['blue', 'shoes'] as $term ) {
    $result = str_replace($term, "<span style=\"background:yellow\">$term</span>", $title);
}
echo $result;
// This will highlight any instances of "blue" or "shoes" in any order in the result,
// even though the MySQL query searched for those terms in that specific order

Answer 1

另一个版本使用implode()构建搜索模式，使用preg_replace()执行实际替换：

$haystacks = [
    "Don't step on my blue suede shoes",
    "... his fancy shoes and his baby blues...",
    "blue shoes under the blue sky",
];
$needles = ['blue', 'shoes'];
$format = '<span style="background:red">%s</span>';

function highlightMatches($needles, $haystack, $format)
{
    $search = '('.implode(')(.+?)(', $needles).')';
    $replace = '';
    $gaps_count = count($needles) - 1;
    foreach ($needles as $k => $needle) {
        $replace .= sprintf($format, '\\'.($k * 2 + 1));
        if ($k < $gaps_count) {
            $replace .= '\\'.($k *2 + 2);
        }
    }

    return preg_replace("/$search/", $replace, $haystack);
}


foreach ($haystacks as $haystack) {
    echo highlightMatches($needles, $haystack, $format)."<br>";
}

如果数据库查询可用于编辑，我将尝试使用数据库查询进行突出显示。

Answer 2

您提到了mysql，因此在查找所讨论的行时，我将介绍与您的请求非常接近的内容。

WHERE MATCH(col) AGAINST(+"blue shoes" IN BOOLEAN MODE)

如果您的问题只涉及PHP代码，那么删除mysql标记。

Answer 3

您必须使用PHP生成regexp模式：

function highlightMatches(array $searchTerms, string $string): string {
    $result = $string;

    foreach ($searchTerms as $i => $term) {
        $previous = array_map(function($item) {
            return "($item)";
        }, array_slice($searchTerms, 0, $i + 1));
        
        $pattern = implode(".+", $previous);
        
        $matches = [];
        preg_match("/$pattern/", $string, $matches);
        
        $lastMatch = array_pop($matches);
        
        if ($lastMatch) {
            $result = str_replace($lastMatch, "<span style=\"color: red;\">$lastMatch</span>", $result);
        }
    }
    
    return $result;
}


$searchTerms = ["first", "second", "third"];

$strings = [
    "first second third",
    "third second first",
    "second third first",
    "third first second",
];

foreach ($strings as $str) {
    echo $str . ":\t" . highlightMatches($searchTerms, $str) . "\n";
}