XML - getting value from namespace using SimpleXML

Question

I'm having an issue getting at a particular namespace value using Simple XML.

Here's a snippet from the XML file:

<message xmlns:blend="http://www.blendlabs.com"
 xmlns:ulad="http://www.datamodelextension.org/Schema/ULAD"
 xmlns="http://www.mismo.org/residential/2009/schemas"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xmlns:xlink="http://www.w3.org/1999/xlink"
 targetnamespace="http://www.mismo.org/residential/2009/schemas">
  <deal_sets>
    <deal_set>
      <deals>
        <deal>
          <loans>
            <loan loanroletype="SubjectLoan" sequencenumber="1" xlink:label="LOAN_1">
              <extension>
                <other>
                  <blend:loan xlink:label="LOAN_1_BLEND_EXTENSION">
                    <blend:marketing_items>
                      <blend:marketing_item>
                        <blend:marketingtypevalue>DirectMarketingCode</blend:marketingtypevalue>
                        <blend:marketingvalue>google.com</blend:marketingvalue>
                      </blend:marketing_item>
                    </blend:marketing_items>
                  </blend:loan>
                </other>
              </extension>
            </loan>
          </loans>
        </deal>
      </deals>
    </deal_set>
  </deal_sets>
</message>

The value I'm trying to get would be google.com from the blend:marketingvalue field at the end of the snippet.

I can access non-namespace values just fine but I don't really get how to access the nested namespace values for the blend fields.

Here is the code I am try to use:

$xml  = simplexml_load_string($body);
        
$blend = $xml->children('http://www.blendlabs.com');
        
$marketing_value = $xml->DEAL_SETS->DEAL_SET->DEALS->DEAL->LOANS->LOAN->EXTENSION->OTHER->$blend->LOAN->MARKETING_ITEMS->MARKETING_ITEM->MARKETINGVALUE;

echo $marketing_value; // just echo's nothing currently.

So I guess my question is, how do you format it to access nested objects?

Do I need to put the $blend variable in front of each object item?

Is that even how you are supposed to use the children function?

Any help would be much appreciated.

For future questions, please try to provide a [mcve] - the XML you've given is incomplete, making it harder for people to give you tested examples in answers. — IMSoP, Jun 02 '21 at 19:00
@miken32 [Your proposed duplicate](https://stackoverflow.com/questions/595946/parse-xml-with-namespace-using-simplexml) is mostly about XPath, which this question doesn't mention; none of its answers explain correct use of ->children(), which this question identified as the key method. (A few of them mention it, but use it really badly.) I have attempted to write a more complete reference Q&A here: https://stackoverflow.com/questions/44894426/reference-how-do-i-handle-namespaces-tags-and-attributes-with-colon-in-in-si but in this case I felt there was something more specific to be explained. — IMSoP, Jun 02 '21 at 20:50
There are a few answers that use `children()` with a namespace value such as [this one](https://stackoverflow.com/a/21568058/1255289) but I'm fine leaving it as is. It's not a bad question by any means, just seemed like something that has been asked before. — miken32, Jun 02 '21 at 20:54
@miken32 Just for the record, that answer is still relying on the local alias ('event') rather than the actual namespace URI ('http://www.webex.com/schemas/2002/06/service/event'), so it is not good advice. — IMSoP, Jun 08 '21 at 14:10

score 3 · Accepted Answer · answered Jun 02 '21 at 18:57

3

The children() method doesn't return some kind of token for the namespace, it returns a list of elements - the children which are in the given namespace.

The $xml variable represents the top-level message element, which doesn't have any children in the http://www.blendlabs.com namespace, so $xml->children('http://www.blendlabs.com') will just return an empty list. You need to first navigate to the other element, and then get its children in the http://www.blendlabs.com namespace, which will include the loan element.

Since the top level element is in the http://www.mismo.org/residential/2009/schemas namespace, you might need an extra children() call to make sure you select that first.

You didn't provide a complete XML, so I can't test the code (I don't fancy manually writing all those close tags), but it will look something like this:

$marketing_value = (string)
   $xml
   ->children('http://www.mismo.org/residential/2009/schemas')
   ->deal_sets->deal_set->deals->deal->loans->loan->extension->other
   ->children('http://www.blendlabs.com')
   ->loan->marketing_items->marketing_item->marketingvalue;

answered Jun 02 '21 at 18:57

IMSoP

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Thanks for the quick answer and it makes sense. When I plug it in I'm getting this error though: `Fatal error: Uncaught Error: Call to a member function children() on null` – Christian Jun 02 '21 at 19:04
I updated the XML snippet to give a complete one. – Christian Jun 02 '21 at 19:19
@Christian, this code [works perfectly](https://3v4l.org/XlAHR) for me when tested against the XML that you provided above. – Chris Haas Jun 02 '21 at 19:47
Yeah, I see that. Hmm, must be something on my end then. – Christian Jun 02 '21 at 19:57
Confirmed what definitely on my end. Thanks for the help! – Christian Jun 02 '21 at 20:11

score 1 · Answer 2 · answered Jun 02 '21 at 22:05

Since you're looking for getting at a particular namespace value blend:marketingvalue. In that case you could get it directly through XPath.

echo $xml->xpath('//blend:marketingvalue')[0]; //google.com

Notice: xpath returns an array of objects, So Since you have one value access it by first position [0]. However if there are others you can use foreach.

foreach ($xml->xpath('//blend:marketingvalue') as $value) {
    echo "marketing value: ". $value ."<BR>";
}

XML - getting value from namespace using SimpleXML

2 Answers2