Nintex Workflow + InfoPath Form

As most folk would be aware, the guts of an InfoPath form is simply (a lot of) XML.   There is a schema & a bunch of namespaces, but is essentially just XML.

So, if there are elements within the form that you want to retrieve – and do something like save to a database, or use to piece together an email, or some other business logic – then you might want to consider digging inside the XML.

YES – you can certainly have fields that are published out from the form, and will thus become meta data columns within the SharePoint list, but sometimes that’s not wanted (like I had recently).

Having a workflow around an InfoPath form will mean that you can have a bunch of logic & functionality in place, but sometimes you need a little bit more – and have to craft some custom code – eg. call a web service.

The scenario I faced recently required email notifications to include data from the form, BUT these fields are not available via any specific workflow or metadata variables – and some logic needed – eg. skip if “N/A” – or blank.

The solution I’d put in place covers the following :

• Nintex workflow – passes the entire InfoPath form to a Web Service
• Using standard .NET code, determine the elements from the XML (ie. InfoPath form)
• Format the data values into a specific format (for an email in this case – but could be for anything)

 

C# XML Web Service

Starting with the web service is the best, as you won’t be able to add a “Web Service” call to the workflow otherwise – ie. if it doesn’t exist !

The web service will have ONE input variable, which is the binary representation of the form – ie. byte array.

The return value will be a ‘string’ – which I’ll format some text for the email notification.

• Open Visual Studio, and create a new Web Service project
• Add a new method (can replace the default one) – with something like this :

public string ProcessInfoPathForm(byte[] byteArray)

{

       return ‘”hello from Web Service”;

}

• This initial web service method is enough to test out the ‘plumbing’.

Nintex Workflow

• Can then include the web service call within the Nintex Workflow.
• The value to pass to the Web Service method is “[FileData]”
• 

Do Something

As the workflow has been assigned to the forms library itself, all instances of the workflow are ‘form-aware’.  There are workflow variables sourced from the metadata properties in the library – and the ‘entire’ form is available to get into the XML.

So, what’s needed within the web service method is :

• Convert the byte[] to an XmlDocument
• Use XPath queries to get the relevant data items
• String together, update in a database, write to a log, whatever…

Here’s some code to explain this premise :

//convert from byte() to memory stream
MemoryStream ms = new MemoryStream(byteArray);

//load into XML document – for xpath’ing
XmlDocument xDoc = new XmlDocument();
xDoc.Load(ms);

//need namespace manager
XmlNamespaceManager mgr = new XmlNamespaceManager(xDoc.NameTable);

//define the namespace – based on the URI within InfoPath

mgr.AddNamespace("my", schema-uri));

Now that it’s into an XML DOM object, we can use XPath to grab out values.

//determine the XML node for "my:fields"
XmlNode xNode = xDoc.SelectSingleNode("//my:myFields/my:PersonName", mgr);

if (xNode != null)
    personName = valueNode.InnerText;

That’s pretty much it – obviously there is additional XPATH methods needed for a ‘SelectNodes” – in which there’s a collection of items.   I’ve bundled a few such commands into a ‘shared’ or ‘common’ class library for use in projects such as this.

Has been kinda interesting to investigate & process the XML internals of an InfoPath form – via a Web Service – which has been called from a Nintex Workflow – phew !    

🙂