Parse XML in google apps script issue eBay api element txt by name

Ok, so I'm trying to get the eBay item title from the eBay api with the google apps scripts. here is the sample XML output from the url.

<GetSingleItemResponse xmlns="urn:ebay:apis:eBLBaseComponents">
<Timestamp>2017-03-08T20:00:54.557Z</Timestamp>
<Ack>Success</Ack>
<Build>E981_CORE_APILW_4424327_R1</Build>
<Version>981</Version>
<Item>
  <Description>Description</Description>
  <ItemID>132119159999</ItemID>
  <EndTime>2017-04-07T00:11:36.000Z</EndTime>
  <ViewItemURLForNaturalSearch></ViewItemURLForNaturalSearch>
  <ListingType>FixedPriceItem</ListingType>
  <Location>Brooklyn, New York</Location>
  <GalleryURL>GalleryURL</GalleryURL>
  <PictureURL>PictureURL</PictureURL>
  <PrimaryCategoryID>181023</PrimaryCategoryID>
  <PrimaryCategoryName>Home &amp; Garden:Yard, Garden &amp; Outdoor Living:Gardening Supplies:Composting &amp; Yard Waste:Garden Compost Bins</PrimaryCategoryName>
  <BidCount>0</BidCount>
  <ConvertedCurrentPrice currencyID="USD">249.99</ConvertedCurrentPrice>
  <ListingStatus>Active</ListingStatus>
  <TimeLeft>P29DT4H10M42S</TimeLeft>
  <Title>Title</Title>
  <Country>US</Country>
  <AutoPay>false</AutoPay>
  <ConditionID>1000</ConditionID>
  <ConditionDisplayName>New</ConditionDisplayName>
</Item>
</GetSingleItemResponse>

Here is the code.

function myFunction() {
  var item='http://open.api.ebay.com/shopping?callname=GetSingleItem&responseencoding=XML&appid=XXXXXXXXXXXX&siteid=0&version=967&ItemID=132119159999&IncludeSelector=Description';
  var xml = UrlFetchApp.fetch(item).getContentText();
  var root=XmlService.parse(xml).getRootElement();
  var Title=root.getChild('Item').getChild('Title').getText();
  Logger.log(Title); 
}

After running the code, I'm getting error saying the value is null

"TypeError: Cannot call method "getChild" of null."

Solution

You need to pass in the namespace when calling getChild():

var ebay = XmlService.getNamespace('urn:ebay:apis:eBLBaseComponents');
var Title=root.getChild('Item',ebay).getChild('Title',ebay).getText();

The namespace is shown by the xmlns attribute of the root element.

The different forms of getChild() (and other functions) is documented here:

https://developers.google.com/apps-script/reference/xml-service/element