PHP Foreach循环麻烦分析xml数据？

Question

我使用xml api。我使用simplexml_load_string方法解析了xml文件，但我也想循环作者数据。我遇到了一个问题，使用foreach循环来检索数据。我该如何解决这个问题。这是输出。

[0] => SimpleXMLElement Object 
       (
        [title] => Impact of Electron-Electron Cusp on Configuration Interaction Energies     

        [author] => Array 
         (
          [0] => SimpleXMLElement Object 
           (
            [name] => David Prendergast 
           ) 

          [1] => SimpleXMLElement Object 
           (
            [name] => M. Nolan 
           ) 

          [2] => SimpleXMLElement Object 
           (
            [name] => Claudia Filippi 
           ) 

          [3] => SimpleXMLElement Object 
           (
            [name] => Stephen Fahy 
           ) 

          [4] => SimpleXMLElement Object 
           (
            [name] => J. C. Greer 
           ) 
         )    
       ) 

      [1] => SimpleXMLElement Object 
       (
        [title] => Electron thermal conductivity owing to collisions between degenerate electrons 
        [author] => Array 
         (
          [0] => SimpleXMLElement Object 
           (
            [name] => P. S. Shternin 
           ) 

          [1] => SimpleXMLElement Object 
           (
            [name] => D. G. Yakovlev 
           ) 
         )   
       ) 

apicall.php

class arxivApi{ 
    public $search_query = ''; 
    public $start = 0; 
    public $max_results = 2; 
    public $url = "http://export.arxiv.org/api/query?"; 

    public function query($term){ 

     $search_query = "all:".urlencode($term); 
     $q = array(); 
     $param = array( 
       'search_query' => $search_query, 
       'start'  => $this->start, 
       'max_results' => $this->max_results 
      ); 
     foreach ($param as $key => $value) { $q[] = $key . '=' . $value; } 
     $httpquery = implode('&',$q); 
     $url = $this->url.$httpquery; 
     $xml = $this->load_file_from_url($url); 
     $result = $this->parse($xml); 
    } 

    public function load_file_from_url($url){ 

     $ch = curl_init(); 
     curl_setopt($ch, CURLOPT_URL, $url); 
     curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); 
     $str = curl_exec($ch); 
     $str = simplexml_load_string($str);   
     curl_close($ch); 
     return $str; 

    } 


    public function parse($xml){  

      $data = array();    
      foreach ($xml->entry as $val) {  
        $url = $val->id;  
        $id = strrchr($url,"/"); 
        $id = substr($id,1,strlen($id));  
        $data[] = array(
          'title' => (string)$val->title, 
          'id' => (string)$id, 
          'summary' => (string)$val->summary 
         );   
        $authors = array(); 
         foreach($val->author as $sname){ 
          $authors[] = (string)$sname->name; 
         }      

       } 
       $data[] = array(
          'title' => (string)$val->title, 
          'id' => (string)$val->id, 
          'summary' => (string)$val->summary, 
          'authros' => implode(',',$authors) 
         ); 

      return $data; 
    } 
} 
$result = new arxivApi(); 
$result->query('electron'); 

Answer 1

这是我的问题的解决方案。以前我没有正确地获得作者数组值。代码作者数组细节上的一些小修改正确地提交。

problem.php

public function parse($xml){  

      $data = array();    
      foreach ($xml->entry as $val) {  
        $url = $val->id;  
        $id = strrchr($url,"/"); 
        $id = substr($id,1,strlen($id));  
        $data[] = array(
          'title' => (string)$val->title, 
          'id' => (string)$id, 
          'summary' => (string)$val->summary 
         );   
        $authors = array(); 
         foreach($val->author as $sname){ 
          $authors[] = (string)$sname->name; 
         }      

       } 
       $data[] = array(
          'title' => (string)$val->title, 
          'id' => (string)$val->id, 
          'summary' => (string)$val->summary, 
          'authros' => implode(',',$authors) 
         ); 

      return $data; 
    } 

solution.php

public function parse($xml, $compact=false){ 


      $data = array(); 


      foreach ($xml->entry as $val) { 

       if($compact){ 
        //$url = $val->id; 

        // $id = strrchr($url,"/"); 
        // $id = substr($id,1,strlen($id)); 

        $data[] = array(
          'title' => (string)$val->title, 
          'id' => (string)$id, 
          'summary' => (string)$val->summary 
          //'author' => $val->author->name 
         ); 
       }else{ 
        $authors = array(); 
        if($val->author){ 
         try { 
          foreach ($val->author as $k => $v) { 
           $authors[] = (string)$v->name; 
          } 
         } catch (Exception $e) { 
          $v = $val->author; 
          $authors[] = (string)$v->name; 
         } 
        } 
       } 

        $data[] = array(
          'title' => (string)$val->title, 
          'id' => (string)$val->id, 
          'summary' => (string)$val->summary, 
          'author' => $authors 
         );      
       } 


      return $data; 
    }