如何使用php访问来自URL的xml输出中的数据点？

Question

I am trying to access a single data point from the XML below. My goal would then be to insert into an html table. The following code has been giving me a stdClass Object and I can't figure out how to grab a single data point.

Here is the XML:

<?xml version="1.0" encoding="utf-8"?>
<response>
  <status>
    <code>0</code>
    <message>OK</message>
  </status>
  <data _idtype="ticker" _id="QYLD" _MstarId="F00000QEMN" _CurrencyId="CU$$$$$USD">
    <api _id="z87pq63qh3gbhraf">
      <TS-DayEndTradingVolume>55769</TS-DayEndTradingVolume>
      <TS-DayEndNAV>25.11</TS-DayEndNAV>
      <DP-NAVChange>0.11</DP-NAVChange>
      <DP-NAVChangePercentage>0.440000</DP-NAVChangePercentage>
      <FNA-FundNetAssets>186075814</FNA-FundNetAssets>
      <DP-DayEndDate>2018-02-27</DP-DayEndDate>
      <TS-MarketPriceOpen>25.2</TS-MarketPriceOpen>
      <PS-PriceToEarnings>0.03678</PS-PriceToEarnings>
      <TS-DayEndMarketPrice>25.06</TS-DayEndMarketPrice>
      <DMP-MarketPriceChange>-0.07</DMP-MarketPriceChange>
      <DMP-MarketPriceChangePercentage>-0.278552</DMP-MarketPriceChangePercentage>
      <DTTRV-NAV>24.98000</DTTRV-NAV>
      <DMP-SharesOutstanding>7448991.76741</DMP-SharesOutstanding>
      <DP-PremiumDiscount>0.32</DP-PremiumDiscount>
    </api>
  </data>
</response>

And the PHP:

$xml = simplexml_load_file($url); // URL with above XML

$jsonConvert = json_encode($xml);

$singleDataPoint = json_decode($jsonConvert);

print_r($singleDataPoint)

?>

Answer 1

Actually your json functions are not doing anything at all. json_encode is the opposite of json_decode, so you can just completely omit those two lines.

The contents of the data points can be found, for example:

$xml = simplexml_load_file($url);
var_dump($xml->data->api->{'TS-DayEndTradingVolume'}->__tostring());

If you're just echoing the value or using it in a string context, you don't need __toString() since that will be implied, but beware that without this, it is really an instance of an SimpleXMLElement object, not an actual string.