使用PHP將XML轉換爲JSON，同時保留陣列

Question

我需要將XML文檔轉換爲JSON，以便輕鬆訪問JavaScript中的數據。我目前使用這種方法將XML轉換成JSON：

json_encode(new SimpleXMLElement($xml, LIBXML_NOCDATA)); 

不過，我遇到了一個問題，當一個元素只包含1個元素。在使用SimpleXML進行分析時，它被視爲一個對象而不是數組。我希望它們始終被視爲數組，除非該元素只包含文本。

實施例：

$xml = <<<END 
<xml> 
    <TESTS> 
    <TEST>TEXT HERE</TEST> 
    </TESTS> 
</xml> 
END; 

echo json_encode(new SimpleXMLElement($xml, LIBXML_NOCDATA)); 

此輸出：

{"TESTS":{"TEST":"TEXT HERE"}} 

如果我下添加其他元件，則輸出是我希望它：

$xml = <<<END 
<xml> 
    <TESTS> 
    <TEST>TEXT HERE</TEST> 
    <TEST>MORE TEXT HERE</TEST> 
    </TESTS> 
</xml> 
END; 

echo json_encode(new SimpleXMLElement($xml, LIBXML_NOCDATA)); 

輸出：

{"TESTS":{"TEST":["TEXT HERE","TEXT HERE"]}} 

請注意，元素包含在JSON數組內而不是JSON對象中。有沒有辦法強制元素被解析爲數組？

Answer 1

我不得不面對同樣的情況。以下是該問題的第一個快速解決方案 - 適用於您的示例。

class JsonWithArrays 
{ 
    protected $root, $callback; 

    public function __construct(SimpleXMLElement $root) 
    { 
     $this->root = $root; 
    } 

    /** 
    * Set a callback to return if a node should be represented as an array 
    * under any circumstances. 
    * 
    * The callback receives two parameters to react to: the SimpleXMLNode in 
    * question, and the nesting level of that node. 
    */ 
    public function use_callback_forcing_array ($callback) 
    { 
     $this->callback = $callback; 
     return $this; 
    } 

    public function to_json() 
    { 
     $transformed = $this->transform_subnodes($this->root, new stdClass(), 0); 
     return json_encode($transformed); 
    } 

    protected function transform_subnodes (SimpleXMLElement $parent, stdClass $transformed_parent, $nesting_level) 
    { 
     $nesting_level++; 

     foreach($parent->children() as $node) 
     { 
      $name = $node->getName(); 
      $value = (string) $node; 

      if (count($node->children()) > 0) 
      { 
       $transformed_parent->$name = new stdClass(); 
       $this->transform_subnodes($node, $transformed_parent->$name, $nesting_level); 
      } 
      elseif (count($parent->$name) > 1 or $this->force_array($node, $nesting_level)) 
      { 
       $transformed_parent->{$name}[] = $value; 
      } 
      else 
      { 
       $transformed_parent->$name = $value; 
      } 
     } 

     return $transformed_parent; 
    } 

    protected function force_array ($node, $nesting_level) 
    { 
     if (is_callable($this->callback)) 
     { 
      return call_user_func($this->callback, $node, $nesting_level); 
     } 
     else 
     { 
      return false; 
     } 
    } 
} 

$xml = <<<END 
<xml> 
    <TESTS> 
    <TEST>TEXT HERE</TEST> 
    </TESTS> 
</xml> 
END; 

$xml2 = <<<END 
<xml> 
    <TESTS> 
    <TEST>TEXT HERE</TEST> 
    <TEST>MORE TEXT HERE</TEST> 
    </TESTS> 
</xml> 
END; 

// Callback using the node name. Could just as well be done using the nesting 
// level. 
function cb_testnode_as_array(SimpleXMLElement $node, $nesting_level) 
{ 
    return $node->getName() == 'TEST'; 
} 

$transform = new JsonWithArrays(new SimpleXMLElement($xml, LIBXML_NOCDATA)); 
echo $transform 
    ->use_callback_forcing_array('cb_testnode_as_array') 
    ->to_json(); 

echo PHP_EOL; 

$transform2 = new JsonWithArrays(new SimpleXMLElement($xml2, LIBXML_NOCDATA)); 
echo $transform2 
    ->use_callback_forcing_array('cb_testnode_as_array') 
    ->to_json(); 

Answer 2

echo json_encode(json_decode(json_encode(new SimpleXMLElement($xml, LIBXML_NOCDATA)), true)); 

真的，這是很多愚蠢的，但你首先如果所有轉換爲對象，然後在陣列解碼並轉換成JSON像數組風格..））