PHP cdata 处理(详细介绍)

当时在网上找了一个cdata的转换器， 修改之后， 将cdata标签给过滤掉。如下

 // states:
        //
        //     'out'
        //     '<'
        //     '<!'
        //     '<!['
        //     '<![c'
        //     '<![cd'
        //     '<![cdat'
        //     '<![cdata'
        //     'in'
        //     ']'
        //     ']]'
        //
        // (yes, the states a represented by strings.)
        //
        $state = 'out';
        $a = str_split($xml);
        $new_xml = '';
        foreach ($a as $k => $v) {
            // deal with "state".
            switch ( $state ) {
                case 'out':
                    if ( '<' == $v ) {
                        $state = $v;
                    } else {
                        $new_xml .= $v;
                    }
                break;
                case '<':
                    if ( '!' == $v  ) {
                        $state = $state . $v;
                    } else {
                        $new_xml .= $state . $v;
                        $state = 'out';
                    }
                break;
                 case '<!':
                    if ( '[' == $v  ) {
                        $state = $state . $v;
                    } else {
                        $new_xml .= $state . $v;
                        $state = 'out';
                    }
                break;
                case '<![':
                    if ( 'c' == $v  ) {
                        $state = $state . $v;
                    } else {
                        $new_xml .= $state . $v;
                        $state = 'out';
                    }
                break;
                case '<![c':
                    if ( 'd' == $v  ) {
                        $state = $state . $v;
                    } else {
                        $new_xml .= $state . $v;
                        $state = 'out';
                    }
                break;
                case '<![cd':
                    if ( 'a' == $v  ) {
                        $state = $state . $v;
                    } else {
                        $new_xml .= $state . $v;
                        $state = 'out';
                    }
                break;
                case '<![cda':
                    if ( 't' == $v  ) {
                        $state = $state . $v;
                    } else {
                        $new_xml .= $state . $v;
                        $state = 'out';
                    }
                break;
                case '<![cdat':
                    if ( 'a' == $v  ) {
                        $state = $state . $v;
                    } else {
                        $new_xml .= $state . $v;
                        $state = 'out';
                    }
                break;
                case '<![cdata':
                    if ( '[' == $v  ) {
                        $cdata = '';
                        $state = 'in';
                    } else {
                        $new_xml .= $state . $v;
                        $state = 'out';
                    }
                break;
                case 'in':
                    if ( ']' == $v ) {
                        $state = $v;
                    } else {
                        $cdata .= $v;
                    }
                break;
                case ']':
                    if (  ']' == $v  ) {
                        $state = $state . $v;
                    } else {
                        $cdata .= $state . $v;
                        $state = 'in';
                    }
                break;
                case ']]':
   if (  '>' == $v  ) {
    $new_xml .= htmlentities($cdata);
#       $new_xml.= $cdata;
//                        $new_xml .= str_replace('>','>',
  //                                  str_replace('>','<',
    //                                str_replace('"','"',
      //                              str_replace('&','&',
        //                            $cdata))));
                        $state = 'out';
                    } else {
                        $cdata .= $state . $v;
                        $state = 'in';
                    }
                break;
            } // switch
        }
        //
        // return.
        //
            return $new_xml;

最近发现，总是有alert发出来， 说是simplexml解析出错。

发现是原来有xml的数据是<![cdata[domain[test]]] >. 出现了连续的3个]， 造成上面的解析函数不能处理。

而且这个问题很难修正， 你不知道下次会不会有4， 5个]出现。

所以决定还是将这段解析 的代码换成dom xml，本身 dom的处理还是比较简单的，

包含domelement, domdocument, domnodelist, domnode几个 component.

对于 domnode有nodevalue, nodetype, nodename的成员函数。

首先先用loadxml将string转化为domdocument对像， 再用getelementsbytagname转化为domnodelist对像， 再使用->item(0)转化为domnode， 然后就可以使用上面的三种方法了。

对于 <aa color='red'>test</aa>这种xml标签， 要使用 attribute函数。