Problem with validation of SOAP request with Zeep (python)

Question

I have problems to get SOAP request through Zeep, I get a (client) validation error... I have also tested with SoapUI and that does NOT give me the same validation error...

The specification below is from the server... Based on that specification, the OrderStatus and SynchStatus are needed to perform the request.

<soapenv:Envelope xmlns:soapenv=http://schemas.xmlsoap.org/soap/envelope/ xmlns:web="WebServiceProvider">
   <soapenv:Header/>
   <soapenv:Body>
      <web:Order_Get>
         <!--Optional:-->
         <web:orderOptions>
            <web:FromDate>?</web:FromDate>
            <web:ToDate>?</web:ToDate>
            <web:OrderStatus>?</web:OrderStatus>
            <web:SynchStatus>?</web:SynchStatus>
            <!--Optional:-->
            <web:OrderNumber>?</web:OrderNumber>
            <web:FromOrderNumberToLastRecieved>?</web:FromOrderNumberToLastRecieved>
            <web:PaymentStatus>?</web:PaymentStatus>
         </web:orderOptions>
      </web:Order_Get>
   </soapenv:Body>
</soapenv:Envelope>

However, executing this from the SoapUI without OrderStatus and SynchStatus will give me a list of all the orders for the specified dates:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:web="WebServiceProvider">
   <soapenv:Header/>
   <soapenv:Body>
      <web:Order_Get>
         <web:orderOptions>
            <web:FromDate>2021-03-30</web:FromDate>
            <web:ToDate>2021-03-31</web:ToDate>
         </web:orderOptions>
      </web:Order_Get>
   </soapenv:Body>
</soapenv:Envelope>

I want to do the same with Zeep (https://github.com/mvantellingen/python-zeep) but the client validation fails...

I initiate the request with the following code:

api_url = 'https://abc.se/Webservice20/v3.0/webservice.asmx?WSDL'
session.auth = HTTPDigestAuth(username, password)
api = Client(api_url, transport=Transport(session=session))

And then I try to execute the following request:

order_options = {
  'FromDate': '2021-03-30',
  'ToDate': '2021-03-31',
}
orders = api.service.Order_Get(orderOptions=order_options)

This will result in the following error:

zeep.exceptions.ValidationError: Missing element OrderStatus (Order_Get.orderOptions.OrderStatus)

If I add OrderStatus to the request, I will get a validation error saying that SynchStatus is missing. When that has been added as well, the request is sent to the server.

I.e. it seems like the zeep client is more strict with regards to validating the data in the request than what the server is... Is there a way to force the client to skip this validation?

Many thanks in advance!

score 2 · Accepted Answer · answered Apr 01 '21 at 11:33

2

Searched a bit more and found a workaround in this post: Getting zeep.exceptions.ValidationError: Missing element for method that worked with suds

So the solution in my case looks like this:

from zeep import xsd
...

order_options = {
  'FromDate': '2021-03-30',
  'ToDate': '2021-03-31',
  'OrderStatus': xsd.SkipValue,
  'SynchStatus': xsd.SkipValue,
}

response = api.service.Order_Get(orderOptions=order_options)

This will block zeep from doing client side validation of the parameters OrderStatus and SynchStatus.

answered Apr 01 '21 at 11:33

Tobias Gårdner

103
1
9

*Zeep will automatically validate that all the required values are set when calling an operation. If you want to force a value to be ignored and left out of the generated XML then you can assign the zeep.xsd.SkipValue constant* [(*)](https://readthedocs.org/projects/python-zeep/downloads/pdf/latest/). Nice find. +1 – Bogdan Apr 01 '21 at 17:16

score 1 · Answer 2 · answered Apr 01 '21 at 10:31

it seems like the zeep client is more strict with regards to validating the data in the request than what the server is...

Looks like it.

Looking at the request SoapUI generates based on the WSDL, the two fields you mention are mandatory:

 <web:orderOptions>
    <web:FromDate>?</web:FromDate>
    <web:ToDate>?</web:ToDate>
    <web:OrderStatus>?</web:OrderStatus>
    <web:SynchStatus>?</web:SynchStatus>
    <!--Optional:-->
    <web:OrderNumber>?</web:OrderNumber>
    <web:FromOrderNumberToLastRecieved>?</web:FromOrderNumberToLastRecieved>
    <web:PaymentStatus>?</web:PaymentStatus>
 </web:orderOptions>

So the error that the zeep client displays is correct. Zeep inspects the WSDL and generates the corresponding code to use the types in the contract. Your WSDL contract says that OrderStatus and SynchStatus are mandatory. The fact that the server doesn't validate them shows a problem: the web service isn't respecting it's own documented contract

The WSDL and the behavior of the web service should be the same. I suggest you contact the web service owners and ask about this behavior. It might be a validation missing on the server and what you get is just some side effect of that, or the behavior is intentional but someone forgot to update the WSDL to say that you can also make the call without those parameters.

Meanwhile, the workaround is very simple. Download the WSDL, change it to make the two fields optional, then feed this changed WSDL to zeep for it to generate the code, instead of using the original WSDL. You should however clarify this with the web service provider. If it's indeed a neglect of someone, this might be spotted at some point and fixed, making your workaround call fail a server validation because of the missing fields.

Problem with validation of SOAP request with Zeep (python)

2 Answers2