InfoPath Dev

I am writing a code that would programatically remove any content from an Attachment control.  There is a nice article about this from bizsupportonline >>

http://www.bizsupportonline.net/blog/2009/10/delete-remove-clear-attachment-infopath-form/

a. I created an InfoPath 2010 form, with an Attachment control. I applied this code to the form's Loading Event.  I published to SharePoint 2010; and set the form library to 'Open in Browser'

b. I then added a document and attached a file to the document.

This solution works, but only when I reopen using "Edit Microsoft InfoPath" 

When open the form using a browser (Windows 7 Enterprise SP1), I would get a warning message with a correlation id.  The trace log gave me this message:

"Business logic failed due to an exception. (User: , Form Name: AttachmentDemo, IP: , Request: , Form ID: urn:schemas-microsoft-com:office:infopath:AttachmentDemo:-myXSD-2012-12-05T20-59-41, Type: SchemaValidationException, Exception Message: Schema validation found non-datatype errors.)"

Is ther something that I should do differently to clear an attachment control in browser mode?

In browser forms, even if you use attachment.SetValue(""); to clear a field, it will be treated as non-empty when you try to add the nil attribute.  Instead of that line, you can use this, which will work in both the filler and the browser:

                if (attachment.MoveToFirstChild())
                {
                    attachment.DeleteSelf();
                }

But is there a reason you're using code to clear out attachments?  This can be done with rules just fine.

 Thanks for your reply. 

The reason that I am not using rules:  the original posting did not offer such a solution.  You either did it manually or use his script.

My project requirements are:

1. Create a form solution published to SharePoint.
2. Add a feature that allow users to upload documents to a document library on the same form.  No switching pages for end users -- it should be seamless.
3. Clear the attachment to upload another next document.  Having users to manual remove the exiting content is not acceptable.  (YUP, I am programming something that SharePoint already does well, but in InfoPath)
   

I found this solution >> http://blogs.msdn.com/b/infopath/archive/2006/11/28/the-xsi-nil-attribute.aspx  and tested the script.

1. This solution includes "node.DeleteSelf()" but require that I set a value to the node.
2. In the example it set a date value to the node.  I guess he was trying to clear a date field. I do not know how to set a value to an attachment; nor understand why I should do so.
   
3. When I implemented the code, it **almost** works.  After running the code, I get a validation error (red asterisk) on the attachment.  This would not go away until I attach a new document.
   

I see.  The instructions in that new link you've posted are for the opposite of what you're trying to do.  Those instructions show how to remove a nil attribute and then set a field's value, but what you need to do is clear the field's value and add a nil attribute.

I believe that if you use the code modification I indicated in my last post, you should be all set.  Did you try that?

 Yes I did try it -- copied the exact script which resulted in the validation error.

After further experimenting, this solution finally did the trick:

 public void FormEvents_ViewSwitched(object sender, ViewSwitchedEventArgs e)
        {
            
            XPathNavigator root = MainDataSource.CreateNavigator();
            XPathNavigator attachment = root.SelectSingleNode("//my:myFields/my:Attachment", NamespaceManager);
                        
                  
            if (attachment.MoveToAttribute("nil", attachment.LookupNamespace("xsi")))
            {
                attachment.DeleteSelf();
            }
            attachment.SetValue("");
            
        }

Thanks for your insight!

Well, that's still not really how it should be.  Are you saying that this causes a validation error?

public void FormEvents_ViewSwitched(object sender, ViewSwitchedEventArgs e)
 {

 XPathNavigator root = MainDataSource.CreateNavigator();
 XPathNavigator attachment = root.SelectSingleNode("//my:myFields/my:Attachment", NamespaceManager);
                       
                 
  if (!attachment.MoveToAttribute("nil", attachment.LookupNamespace("xsi")))
{
 if (attachment.MoveToFirstChild())
 {
   attachment.DeleteSelf();
 }
 attachment.CreateAttribute("xsi", "nil",attachment.LookupNamespace("xsi"), "true");
 }

}

 No. The script that I posted does not cause validation error.

The error occurred when I copied the script from the 2nd link, which dateTime object as a parameter to SetValue. 

Do I really need to CreateAttribute after DeleteSelf?

 I tired your second code (which has the CreateAttribute line).  This successfully cleared the attachment control -- and it does not leave me with a validation error.

Thanks for your help!