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我有一个搜索结果，它在截断完整字符串时严格计算 SEARCH TERM 前后的字符数。不幸的是，这会导致输出切断中间的单词。（......计数前后都有一个椭圆）

我试图让搜索结果仅在空白处与单词中间截断完整的字符串。

这是功能：

private function _highlight_results(){

    $GLOBALS['_SEARCH_SUMMARY_LENGTH'] = 24;

    foreach($this->results as $url => &$this_result){
        if(!$this_result['url_display'] && $this_result['url']){
            $this_result['url_display'] = $this_result['url'];
        }
        foreach($this_result['search_term'] as $search_term){
            $search_term = preg_quote($search_term,'/');

            foreach(array('title','summary','url_display') as $highlight_item){
                if($this_result[$highlight_item] && preg_match('/'.$search_term.'/i',$this_result[$highlight_item])){
                    if($highlight_item != 'url_display' && strlen($this_result[$highlight_item]) > $GLOBALS['_SEARCH_SUMMARY_LENGTH']){
                        $boobs = ceil(($GLOBALS['_SEARCH_SUMMARY_LENGTH']-strlen($this->_search_term))/2);
                        preg_match('/(.{0,'.$boobs.'})('.$search_term.')(.{0,'.$boobs.'})/i',$this_result[$highlight_item],$matches);
                        // want to even out the strings a bit so if highlighted term is at end of string, put more characters infront.
                        $before_limit = $after_limit = ($boobs - 2);
                        if(strlen($matches[1])>=$before_limit && strlen($matches[3])>=$after_limit){
                            // leave limit alone.
                        }else if(strlen($matches[1])<$before_limit){
                            $after_limit += $before_limit - strlen($matches[1]);
                            $before_limit = strlen($matches[1]);
                            preg_match('/(.{0,'.($before_limit+2).'})('.$search_term.')(.{0,'.($after_limit+2).'})/i',$this_result[$highlight_item],$matches);
                        }else if(strlen($matches[3])<$after_limit){
                            $before_limit += $after_limit - strlen($matches[3]);
                            $after_limit = strlen($matches[3]);
                            preg_match('/(.{0,'.($before_limit+2).'})('.$search_term.')(.{0,'.($after_limit+2).'})/i',$this_result[$highlight_item],$matches);
                        }
                        $this_result[$highlight_item] = (strlen($matches[1])>$before_limit) ? '...'.substr($matches[1],-$before_limit) : $matches[1];
                        $this_result[$highlight_item] .= $matches[2];
                        $this_result[$highlight_item] .= (strlen($matches[3])>$after_limit) ? substr($matches[3],0,$after_limit).'...' : $matches[3];

                    }

                }else if(strlen($this_result[$highlight_item]) > $GLOBALS['_SEARCH_SUMMARY_LENGTH']){
                    $this_result[$highlight_item] = substr($this_result[$highlight_item],0,$GLOBALS['_SEARCH_SUMMARY_LENGTH']).'...';
                }
            }
        }

        foreach($this_result['search_term'] as $search_term){
            $search_term = preg_quote($search_term,'/');

            foreach(array('title','summary','url_display') as $highlight_item){
                $this_result[$highlight_item] = preg_replace('/'.$search_term.'/i','<span id="phpsearch_resultHighlight">$0</span>',$this_result[$highlight_item]);
            }
        }
    }
}

这就是我的想法......在显示字符串输出之前，脚本应该使用“查找”椭圆和立即字符的函数循环字符串，然后在之后删除字符并继续循环直到出现空格成立。然后，下一个循环将“查找”一个字符，然后是一个椭圆，然后删除该字符并继续循环，直到在椭圆之前找到一个空格。

这是我上面描述的一些非常可悲的伪代码：

WHILE (not the end of the string) {
 // NOT SURE IF I NEED A FOREACH LOOP HERE TO CHECK EACH CHAR
    IF ( ^ ('...' and an immediate char are found) ) {
           delete chars until a white space is found;

            // if '...' is deleted along with the chars, then put the '...' back in:
            //string .= '...' . string;
    }
    IF ( $ (a char and an immediate '...' are found) ) {
           delete chars until a white space is found;

            // if '...' is deleted along with the chars, then put the '...' back in:
            //string .= string . '...';
    }
}
PRINT string;

我认为您可以从上面的内容中了解我在寻找什么。我已经研究并测试了 wordwrap() 但仍然没有找到答案。

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1 回答 1

0

这是一种应该可以正常工作并且性能也很好的方法。唯一的缺点是它只在空格上打断单词，而且这不能轻易解决，因为没有strrspn可以补充的功能strspn（但可以很容易地编写并用于扩展此解决方案）。

function display_short($str, $limit, $ellipsis = '...') {
    // if all of it fits there's nothing to do
    if (strlen($str) <= $limit) {
        return $str;
    }

    // $ellipsis will count towards $limit
    $limit -= strlen($ellipsis);

    // find the last space ("word boundary")
    $pos = strrpos($str, ' ', $limit - strlen($str));

    // if none found, prefer breaking into the middle of
    // "the" word instead of just giving up
    if ($pos === false) {
        $pos = $limit;
    }

    return substr($str, 0, $pos).$ellipsis;
}

测试：

$string = "the quick brown fox jumps over the lazy dog";
for($limit = 10; $limit <= strlen($string); $limit += 10) {
    print_r(display_short($string, $limit));
}

看到它在行动。

于 2012-04-25T08:59:05.037 回答