在文本中插入多个链接,忽略恰好插入的匹配项

我正在工作的站点有一个数据库表,其中充满了词汇表术语。我正在构建一个函数,它将使用一些HTML并用工具提示链接替换词汇表术语的第一个实例。

我想底线是,我需要忽略文本,如果它:

• 出现在 < >
• 出现在 <a></a> 标签。

这是我目前掌握的情况。我希望有人能想出一个聪明的解决办法。

function insertGlossaryLinks($html)
{
    // Get glossary terms from database, once per request
    static $terms;
    if (is_null($terms)) {
        $query = Doctrine_Query::create()
            ->select('gt.title, gt.alternate_spellings, gt.description')
            ->from('GlossaryTerm gt');
        $glossaryTerms = $query->rows();

        // Create whole list in $terms, including alternate spellings
        $terms = array();
        foreach ($glossaryTerms as $glossaryTerm) {

            // Initialize with title
            $term = array(
                'wordsHtml' => array(
                    h(trim($glossaryTerm['title']))
                    ),
                'descriptionHtml' => h($glossaryTerm['description'])
                );

            // Add alternate spellings
            foreach (explode(',', $glossaryTerm['alternate_spellings']) as $alternateSpelling) {
                $alternateSpelling = h(trim($alternateSpelling));
                if (empty($alternateSpelling)) {
                    continue;
                }
                $term['wordsHtml'][] = $alternateSpelling;
            }

            $terms[] = $term;
        }
    }

    // Do replacements on this HTML
    $newHtml = $html;
    foreach ($terms as $term) {
        $callback = create_function('$m', 'return \'<a href="javascript:void(0);" class="glossary-term" title="'.$term['descriptionHtml'].'"><span>\'.$m[0].\'</span></a>\';');
        $term['wordsHtmlPreg'] = array_map('preg_quote', $term['wordsHtml']);
        $pattern = '/\b('.implode('|', $term['wordsHtmlPreg']).')\b/i';
        $newHtml = preg_replace_callback($pattern, $callback, $newHtml, 1);
    }

    return $newHtml;
}