Where's my node? Logic Apps Flat File Decode beware suppress empty nodes unintended effect

  • Article

The flat file schema property 'suppress_empty_nodes' is described as "Indicates whether or not to remove empty XML nodes after the parser generates XML instance data." in the documentation https://msdn.microsoft.com/en-us/library/aa559329.aspx

Sandro Pereira blogs about how this can be helpful in his post Teach me something new about Flat Files.

However you will not want to suppress W3C-empty nodes like (i.e. has no value, even if it has attributes):

   <Header BatchDate="2018-11-28" RecordCount="123" PostAmt="123456.1200|123"></Header>

When the node is required in the schema as in:

        <xs:element minOccurs="1" maxOccurs="1" name="Header">

If you run and XML validation on the output which empty node was suppressed you will get an error like this:

        System.Xml.XmlException: The element 'MyRootNode' has invalid child element 'Loop'. List of possible elements expected: 'Header'.

So in the schemaInfo beware

        suppress_empty_nodes="true"

and as appropriate change it to

        suppress_empty_nodes="false"