将JSON转换为XML时限制XML数据 - PHP

Question

我正在使用此代码将JSON转换为XML，并且一切正常。我在XML中获得200条记录，但我想将其限制为50.我只是想创建包含最新50条记录的XML文件。而不是将我们在JSON中的任何内容转换为XML。

function array_to_xml($data, &$xml_data) { 
    foreach($data as $key => $value) { 
     if(is_numeric($key)){ 
      $key = 'item'.$key; //dealing with <0/>..<n/> issues 
     } 
     if(is_array($value)) { 
      $subnode = $xml_data->addChild($key); 
      array_to_xml($value, $subnode); 
     } else { 
      $xml_data->addChild("$key",htmlspecialchars("$value")); 
     } 
    } 
} 
$xml_data = new SimpleXMLElement('<?xml version="1.0"?><data></data>'); 
$json_file = file_get_contents("/directory/jsonfile.json"); 
$json_data = json_decode($json_file, true); 
$json_data = array_slice((array)$json_data, 0, 50); 
array_to_xml($json_data,$xml_data); 
$result = $xml_data->asXML('/directory/xmlfile.xml'); 

XML

这是我迄今为止节点是什么样子：

<dateLastModified>1493913962397</dateLastModified> 

XML样本数据

<data> 
    <total>212</total> 
    <start>0</start> 
    <count>212</count> 
    <data> 
     <item0> 
      <id>123</id> 
      <title>abc-test1</title> 
      <clientContact> 
       <id>111</id> 
       <firstName>abc</firstName> 
       <lastName>xyz</lastName> 
       <email>[email protected]</email> 
      </clientContact> 
      <isOpen>1</isOpen> 
      <isPublic>1</isPublic> 
      <isJobcastPublished>1</isJobcastPublished> 
      <owner> 
       <id>222</id> 
       <firstName>testname</firstName> 
       <lastName>testlastname</lastName> 
       <address> 
        <address1>test address,</address1> 
        <address2>test</address2> 
        <city>City</city> 
        <state>state</state> 
        <zip>2222</zip> 
        <countryID>22</countryID> 
        <countryName>Country</countryName> 
        <countryCode>ABC</countryCode> 
       </address> 
       <email>[email protected]</email> 
       <customText1>test123</customText1> 
       <customText2>testxyz</customText2> 
      </owner> 
      <publicDescription> 
       <p>test info</p> 
      </publicDescription> 
      <status>test</status> 
      <dateLastModified>22222</dateLastModified> 
      <customText4>test1</customText4> 
      <customText10>test123</customText10> 
      <customText11>test</customText11> 
      <customText16>rtest</customText16> 
      <_score>123</_score> 
     </item0> 
     <item1> 
     ... 
     </item1> 
     ... 
    </data> 
</data> 

Answer 1

很多这取决于你有多大的控制在数据。如果可以按时间戳排序数据，则可以在计数器达到50时添加计数器并退出循环。

function array_to_xml($data, &$xml_data) { 
    $count = 0; 
foreach($data as $key => $value) { 
    $count++; 
    if($count == 50) { 
     exit; //or return; 
    } 
    if(is_numeric($key)){ 
     $key = 'item'.$key; //dealing with <0/>..<n/> issues 
    } 
    if(is_array($value)) { 
     $subnode = $xml_data->addChild($key); 
     array_to_xml($value, $subnode); 
    } else { 
     $xml_data->addChild("$key",htmlspecialchars("$value")); 
    } 
} 
} 
$xml_data = new SimpleXMLElement('<?xml version="1.0"?><data></data>'); 
$json_file = file_get_contents("/directory/jsonfile.json"); 
$json_data = json_decode($json_file, true); 
array_to_xml($json_data,$xml_data); 
$result = $xml_data->asXML('/directory/xmlfile.xml');