Using complex objects via a Web Service from Powershell?

Question

I've been trying to make use of a vendor supplied Web Service system via Powershell (I'm running 4.0). The following is the code I've used to set up the proxy to use the service :

$uri = http://somehost.employer.net:9999/AdministrationService?wsdl
$webSvc = New-WebServiceProxy -Uri $uri -namespace WebServiceProxy -Credential $TestCreds_NonPriv

Currently, I'm interested in two methods that the service exposes, "SaveAttributes" and "GetAllAttributes", wsdl definitions as here:

  <xsd:element name="SaveAttributes">
   <xsd:complexType>
    <xsd:sequence>
     <xsd:element minOccurs="0" name="Id" nillable="true" type="xsd:string"/>
     <xsd:element minOccurs="0" name="attributes" nillable="true" type="q5:ArrayOfKeyValueOfstringstring"/>
    </xsd:sequence>
   </xsd:complexType>
  </xsd:element>

  <xsd:element name="GetAllAttributes">
   <xsd:complexType>
    <xsd:sequence>
     <xsd:element minOccurs="0" name="Id" nillable="true" type="xsd:string"/>
    </xsd:sequence>
   </xsd:complexType>
  </xsd:element>

  <xsd:element name="GetAllAttributesResponse">
   <xsd:complexType>
    <xsd:sequence>
     <xsd:element minOccurs="0" name="GetAllAttributesResult" nillable="true" type="q2:ArrayOfKeyValueOfstringstring"/>
    </xsd:sequence>
   </xsd:complexType>
  </xsd:element>

I've successfully used the GetAllAttributes function via :

$websvc.GetAllAttributes('someid')

and this returns me an object which is an array of key value pairs like this :

Key         Value
---         -----
ID          01
PERSONA     [email protected]
NAME        GodEater's real name

If I wish to create a new object on the Web Service, I have to call the "SaveAttributes" function with two parameters, a new "ID" as a string and an Array of Key/Value pairs for the rest of the attributes, and this is where I'm stumped. I'm unable to create a powershell object which gets successfully serialized to the service. What I tried was this:

[WebServiceProxy.ArrayOfKeyValueOfstringstringKeyValueOfstringstring[]]$newentity = @(
    @{Key='PERSONA';Value='[email protected]'},
    @{Key='NAME';Value='Someone Elses Real Name'}
  )
$WebSvc.SaveAttributes('02',$newentity)

But what I get this is this rather perplexing error:

Cannot convert argument "attributes", with value: "WebServiceProxy.ArrayOfKeyValueOfstringstringKeyValueOfstringstring[]", for "SaveAttributes" to type
  "WebServiceProxy.ArrayOfKeyValueOfstringstringKeyValueOfstringstring[]": "Cannot convert the "WebServiceProxy.ArrayOfKeyValueOfstringstringKeyValueOfstringstring" value of type
  "WebServiceProxy.ArrayOfKeyValueOfstringstringKeyValueOfstringstring" to type "WebServiceProxy.ArrayOfKeyValueOfstringstringKeyValueOfstringstring"."
  At line:1 char:1
  + $WebSvc.SaveAttributes('02',$newentity)
  + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodException
    + FullyQualifiedErrorId : MethodArgumentConversionInvalidCastArgument

Now, looking at what the GetAllAttributes returned to me, which should be the same sort of object as I try to feed into the 'attributes' argument of the SaveAttributes method, it seems to serialize slightly differently to the object I've constructed myself.

Result from GetAllAttributes when serialized:

<Objs Version="1.1.0.1" xmlns="http://schemas.microsoft.com/powershell/2004/04">
    <Obj RefId="0">
      <TN RefId="0">
        <T>WebServiceProxy.ArrayOfKeyValueOfstringstringKeyValueOfstringstring[]</T>
        <T>System.Array</T>
        <T>System.Object</T>
      </TN>
      <LST>
        <Obj RefId="1">
          <TN RefId="1">
            <T>WebServiceProxy.ArrayOfKeyValueOfstringstringKeyValueOfstringstring</T>
            <T>System.Object</T>
          </TN>
          <ToString>WebServiceProxy.ArrayOfKeyValueOfstringstringKeyValueOfstringstring</ToString>
          <Props>
            <S N="Key">ID</S>
            <S N="Value">01</S>
          </Props>
        </Obj>
        <Obj RefId="2">
          <TNRef RefId="1" />
          <ToString>WebServiceProxy.ArrayOfKeyValueOfstringstringKeyValueOfstringstring</ToString>
          <Props>
            <S N="Key">PERSONA</S>
            <S N="Value">[email protected]</S>
          </Props>
        </Obj>
        <Obj RefId="3">
          <TNRef RefId="1" />
          <ToString>WebServiceProxy.ArrayOfKeyValueOfstringstringKeyValueOfstringstring</ToString>
          <Props>
            <S N="Key">NAME</S>
            <S N="Value">GodEater's real name</S>
          </Props>
        </Obj>
      </LST>
    </Obj>
  </Objs>

Whilst the object I've created serializes to this:

<Objs Version="1.1.0.1" xmlns="http://schemas.microsoft.com/powershell/2004/04">
    <Obj RefId="0">
      <TN RefId="0">
        <T>System.Collections.Hashtable</T>
        <T>System.Object</T>
      </TN>
      <DCT>
        <En>
          <S N="Key">PERSONA</S>
          <S N="Value"></S>
        </En>
      </DCT>
    </Obj>
  </Objs>
  <Objs Version="1.1.0.1" xmlns="http://schemas.microsoft.com/powershell/2004/04">
    <Obj RefId="0">
      <TN RefId="0">
        <T>System.Collections.Hashtable</T>
        <T>System.Object</T>
      </TN>
      <DCT>
        <En>
          <S N="Key">NAME</S>
          <S N="Value">Someone Elses Real Name</S>
        </En>
      </DCT>
    </Obj>
  </Objs>

Which seems to lack the wrapping around the members of the array, and seems instead to have each item in the array as a standalone object.

Anyone have any ideas?

Answer 1

It seems to be a common problem of passing complex custom types to web service methods in Powershell. Here they recommend to add '-Class' parameter to New-WebServiceProxy: https://groups.google.com/forum/#!msg/microsoft.public.windows.powershell/JWB5yueLtrg/k0zeUUxAkTMJ

In my case it did not help - seems this solution is unstable too. I finally had to use autogenerated namespace to avoid this problem.

Web service proxy should be created without namespace:

$webSvc = New-WebServiceProxy -Uri $uri

Then you create your array in the autogenerated namespace:

        $newentity = New-Object -TypeName ($webSvc.GetType().Namespace + '.ArrayOfKeyValueOfstringstringKeyValueOfstringstring[]') -ArgumentList 2
        $newentity[0] = New-Object -TypeName ($webSvc.GetType().Namespace + '.ArrayOfKeyValueOfstringstringKeyValueOfstringstring')
        $newentity[0].Key  = 'key0'
        $newentity[0].Value = 'value0'

        $newentity[1] = New-Object -TypeName ($webSvc.GetType().Namespace + '.ArrayOfKeyValueOfstringstringKeyValueOfstringstring')
        $newentity[1].Key = 'key1'
        $newentity[1].Value = 'value1'

        $WebSvc.SaveAttributes('02',$newentity)

Looks clumsy, but at least it worked for me.

Answer 2

Try forcing Key/Value pairs to be of the WebServiceProxy.ArrayOfKeyValueOfstringstringKeyValueOfstringstring type:

$Properties = @(
    @{Key='PERSONA';Value='[email protected]'},
    @{Key='NAME';Value='Someone Elses Real Name'}
)

[WebServiceProxy.ArrayOfKeyValueOfstringstringKeyValueOfstringstring[]]$newentity = $Properties | ForEach-Object {
    New-Object -TypeName 'WebServiceProxy.ArrayOfKeyValueOfstringstringKeyValueOfstringstring' -Property $_
}

$WebSvc.SaveAttributes('02',$newentity)