lists.asmx | Paul Galvin's SharePoint Space

I was doing some research for someone today around the list.asmx web service provided as part of SharePoint 2010 (and earlier). She was able to get the list items at the root folder (including the names of sub-folders), but couldn’t get items in sub-folders. I did some looking around on the internets and it’s a surprisingly common question. Yet, I couldn’t get a good answer to the simple question, “if I know the folder, how do I get the items in the folder?” To be honest, I didn’t try all that hard since I’ve wanted to figure this one out on my own for a while Smile .

To set this up, I created a site named “Blogging Scenarios” and a custom list named “Custom List with Sub Folders”. I then created folders named:

Year 2005
Year 2006
Year 2007

I added a few items to the folder “Year 2006”. This is what it looks like:

My friend isn’t writing C# code but rather using Java, so the SOAP envelope was what she really needed. To get that, I wrote a bit of jQuery and then used fiddler to get the actual HTTP conversation.

Here’s the relevant jQuery (I copied the code down below if you want to copy/paste):

They first key is to include both a <queryOptions> and <QueryOptions> node. The second key is that the <Folder> node is a URL to which the client has access.

There may be other ways to get this, but this worked well for me when using jQuery.

Here is the SOAP envelope for the above:

<soapenv:Envelope xmlns:soapenv=’http://schemas.xmlsoap.org/soap/envelope/’>
<soapenv:Body>
    <GetListItems xmlns=’http://schemas.microsoft.com/sharepoint/soap/’>
      <listName>Custom List with Sub Folders</listName>
      <viewFields>
        <ViewFields>
          <FieldRef Name=’Title’ />
          <FieldRef Name=’EncodedAbsUrl’ />
        </ViewFields>
      </viewFields>
      <queryOptions>
        <QueryOptions>
          <Folder>http://demoserver1/Blogging Scenarios/lists/Custom List with Sub Folders/Year 2006</Folder>
        </QueryOptions>
      </queryOptions>
    </GetListItems>
</soapenv:Body>
</soapenv:Envelope>

A lot of examples and discussion around this led me to believe that all I need was <QueryOptions> and specify a folder name. For me, I need to both wrap it inside <queryOptions> as well as specify a fully qualified URL for the <Folder> node.

Here’s the jQuery AJAX setup:

$(document).ready(function() {
       var soapEnv =
           "<soapenv:Envelope xmlns:soapenv=’http://schemas.xmlsoap.org/soap/envelope/’> \
               <soapenv:Body> \
                    <GetListItems xmlns=’http://schemas.microsoft.com/sharepoint/soap/’> \
                       <listName>Custom List with Sub Folders</listName> \
                       <viewFields> \
                           <ViewFields> \
                              <FieldRef Name=’Title’ /> \
                              <FieldRef Name=’EncodedAbsUrl’ /> \
                          </ViewFields> \
                       </viewFields> \
                       <queryOptions> \
                         <QueryOptions> \
                           <Folder>http://demoserver1/Blogging Scenarios/lists/Custom List with Sub Folders/Year 2006</Folder> \
                         </QueryOptions> \
                       </queryOptions> \
                   </GetListItems> \
               </soapenv:Body> \
           </soapenv:Envelope>";

</end>

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I discovered today that the GetList() method in lists.asmx web service has to be called very carefully or it’s prone to throw a mysterious “Value cannot be null” exception (and that’s assuming you can get past the even worse generic error message, “Exception of type ‘Microsoft.SharePoint.SoapServer.SoapServerException’ was thrown.”) Specifically, I found that you can’t provide any kind of prefix on the GetList method. The following jQuery snippet illustrates the point:

If you do that, the web service responds with “Value cannot be null” as per this fiddler-provided HTTP transcript:

<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope
     xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"
     xmlns:xsi=”http://www.w3.org/2001/XMLSchema-instance”
     xmlns:xsd="http://www.w3.org/2001/XMLSchema">

<soap:Body>
    <soap:Fault>
      <faultcode>soap:Server</faultcode>
      <faultstring>
        Exception of type ‘Microsoft.SharePoint.SoapServer.SoapServerException’ was thrown.
      </faultstring>
      <detail>
        <errorstring xmlns="http://schemas.microsoft.com/sharepoint/soap/">
Value cannot be null.
        </errorstring>
      </detail>
    </soap:Fault>
</soap:Body>
</soap:Envelope>

Of course, you probably wouldn’t add that “s0” prefix on your own, but some tools are prone to do it (like Eclipse).

This is all the more confusing / frustrating because other methods tolerate prefixes. For instance, the GetListCollection method doesn’t mind if it’s been prefixed, even with nonsense prefixes like “xyzzy”:

This “value cannot be null” seems fairly common with lists.asmx so hopefully this will help someone out in future.

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Paul Galvin's SharePoint Space

Tag Archives: lists.asmx

Lists.asmx, GetListItems and Folders

Lists.asmx, GetList and “Value cannot be null”