使用php在给定php字符串的特定段落上插入自定义html/javascript代码

<div itemprop="articleBody">
<?php
  $needle = "</p>";
  $length = strlen($needle);

  $this_article = $this->item->text;
  $pos1 = strpos($this_article, $needle);
  $pos2 = ($pos1!== 0 && strpos($this_article, $needle, $pos1 + $length)) ? strpos($this_article, $needle, $pos1 + $length): 0;

 $first_para = substr($this_article,0,$pos2);
 $rest_para = substr($this_article,$pos2 + $length); 
    echo $first_para;
    echo JHtml::_('content.prepare', '{loadposition inline-zone}'); 
    echo $rest_para;
?>		
</div>