文章截取摘要，去掉dom标签

<?php
namespace app\service;

class ArticleService
{
    //截取摘要
    public function cutChar(document)
    {document = trim(document);
        if (strlen(document) <= 0) {
            return document;
        }search = array("'<script[^>]*?>.*?</script>'si", // 去掉 javascript
            "'<[\/\!]*?[^<>]*?>'si", // 去掉 HTML 标记
            "'([\r\n])[\s]+'", // 去掉空白字符
            "'/\s(?=\s)/'",
            "'/[nrt]/'",
            "'/[\n\r\t]/'",
            "'/s(?=s)/'",
            "'&(quot|#34);'i", // 替换 HTML 实体
            "'&(amp|#38);'i",
            "'&(lt|#60);'i",
            "'&(gt|#62);'i",
            "'&(nbsp|#160);'i",
        );
        replace = array("", "", "\\1", "\"", "&", "<", ">","");String = @preg_replace(search,replace, document);
        returnthis->sysSubStr(String, 200, true);
    }

    public function sysSubStr(String, Length,Append = false)
    {
        if (strlen(String) <=Length) {
            return String;
        } else {I = 0;
            while (ILength) {
                StringTMP = substr(String, I, 1);
                if (ord(StringTMP) >= 224) {
                    StringTMP = substr(String, I, 3);I = I + 3;
                } elseif (ord(StringTMP) >= 192) {
                    StringTMP = substr(String, I, 2);I = I + 2;
                } else {I = I + 1;
                }StringLast[] = StringTMP;
            }StringLast = implode("", StringLast);
            if (Append) {
                StringLast .= "...";
            }
            returnStringLast;
        }
    }
}