我需要在一个段落中突出显示关键字,就像Google在搜索结果中所做的那样.我们假设我有一个带有博客文章的MySQL数据库.当用户搜索某个关键字时,我希望返回包含这些关键字的帖子,但只显示部分帖子(包含搜索关键字的段落)并突出显示这些关键字.
我的计划是这样的:
你能帮助我一些逻辑,或者至少告诉我我的逻辑是否合适？我正处于PHP学习阶段.
如果它包含html(请注意,这是一个非常强大的解决方案):
$string = '<p>foo<b>bar</b></p>';
$keyword = 'foo';
$dom = new DomDocument();
$dom->loadHtml($string);
$xpath = new DomXpath($dom);
$elements = $xpath->query('//*[contains(.,"'.$keyword.'")]');
foreach ($elements as $element) {
foreach ($element->childNodes as $child) {
if (!$child instanceof DomText) continue;
$fragment = $dom->createDocumentFragment();
$text = $child->textContent;
$stubs = array();
while (($pos = stripos($text, $keyword)) !== false) {
$fragment->appendChild(new DomText(substr($text, 0, $pos)));
$word = substr($text, $pos, strlen($keyword));
$highlight = $dom->createElement('span');
$highlight->appendChild(new DomText($word));
$highlight->setAttribute('class', 'highlight');
$fragment->appendChild($highlight);
$text = substr($text, $pos + strlen($keyword));
}
if (!empty($text)) $fragment->appendChild(new DomText($text));
$element->replaceChild($fragment, $child);
}
}
$string = $dom->saveXml($dom->getElementsByTagName('body')->item(0)->firstChild);
结果是:
<p><span class="highlight">foo</span><b>bar</b></p>
与:
$string = '<body><p>foobarbaz<b>bar</b></p></body>';
$keyword = 'bar';
你得到(分为多行以便于阅读):
<p>foo
<span class="highlight">bar</span>
baz
<b>
<span class="highlight">bar</span>
</b>
</p>
谨防非dom解决方案(如regex或str_replace),因为突出显示类似"div"的东西有完全破坏你的HTML的倾向......这只会"突出"身体中的字符串,永远不会在标签内...
编辑因为您需要Google样式结果,所以这是一种方法:
function getKeywordStubs($string, array $keywords, $maxStubSize = 10) {
$dom = new DomDocument();
$dom->loadHtml($string);
$xpath = new DomXpath($dom);
$results = array();
$maxStubHalf = ceil($maxStubSize / 2);
foreach ($keywords as $keyword) {
$elements = $xpath->query('//*[contains(.,"'.$keyword.'")]');
$replace = '<span class="highlight">'.$keyword.'</span>';
foreach ($elements as $element) {
$stub = $element->textContent;
$regex = '#^.*?((\w*\W*){'.
$maxStubHalf.'})('.
preg_quote($keyword, '#').
')((\w*\W*){'.
$maxStubHalf.'}).*?$#ims';
preg_match($regex, $stub, $match);
var_dump($regex, $match);
$stub = preg_replace($regex, '\\1\\3\\4', $stub);
$stub = str_ireplace($keyword, $replace, $stub);
$results[] = $stub;
}
}
$results = array_unique($results);
return $results;
}
好的,那么它的作用是返回一个带有$maxStubSize它周围单词的匹配数组(即之前的数字的一半,之后的一半)......
所以,给定一个字符串:
<p>a whole
<b>bunch of</b> text
<a>here for</a>
us to foo bar baz replace out from this string
<b>bar</b>
</p>
通话getKeywordStubs($string, array('bar', 'bunch'))将导致:
array(4) {
[0]=>
string(75) "here for us to foo <span class="highlight">bar</span> baz replace out from "
[3]=>
string(34) "<span class="highlight">bar</span>"
[4]=>
string(62) "a whole <span class="highlight">bunch</span> of text here for "
[7]=>
string(39) "<span class="highlight">bunch</span> of"
}
那么,你可以通过对列表进行排序strlen然后选择两个最长的匹配来构建你的结果模糊...(假设php 5.3+):
usort($results, function($str1, $str2) {
return strlen($str2) - strlen($str1);
});
$description = implode('...', array_slice($results, 0, 2));
结果如下:
here for us to foo <span class="highlight">bar</span> baz replace out...a whole <span class="highlight">bunch</span> of text here for
我希望有所帮助......(我觉得这有点......臃肿......我确信有更好的方法可以做到这一点,但这是一种方式)......
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