Identifier 'Submission#0' is not CLS-compliant in Azure functions

Question

I hope somebody could help me on this one. I am implementing an Azure Function where I am trying to serialise an XML message into .Net object. This is the code that I am currently using:

public static void Run(string input, TraceWriter log) 
{
    System.Xml.Serialization.XmlSerializer serializer = new System.Xml.Serialization.XmlSerializer(typeof(App));
    // more code here....
}
public class App
{
    public string DataB { get; set; }
}

However, I always got this error:

2017-01-17T12:21:35.173 Exception while executing function: Functions.ManualXmlToJson. mscorlib: Exception has been thrown by the target of an invocation. System.Xml: Identifier 'Submission#0' is not CLS-compliant.

Parameter name: ident.

I have tried with XmlAttributes, without them. I added the buildOptions:warningsAsErrors as false in project.json file but nothing happens. And to be honest, I ran out of ideas because this code is actually working in an App Console.

I guess is some parameter of something, I would really appreciate if somebody can suggest me how to fix it.

Thanks!

Answer 1

Your best option here will be to factor the class you're attempting to serialize into a separate class library and reference that from your function.

If you implement your App class above in a different assembly, your function code would look like the following:

#r "<yourassemblyname>.dll"

using System;
using <YourClassNamespace>;

public static void Run(string input, TraceWriter log) 
{
    System.Xml.Serialization.XmlSerializer serializer = new System.Xml.Serialization.XmlSerializer(typeof(App));
}

The code above assumes a private assembly reference, where you upload your assembly to a bin folder, inside of your function folder.

You can find more about external references here: https://docs.microsoft.com/en-us/azure/azure-functions/functions-reference-csharp#referencing-external-assemblies

I'm opening an issue to address the CLS compliant name so this is not as confusing: https://github.com/Azure/azure-webjobs-sdk-script/issues/1123

Another option worth trying (which would minimize the changes you'd need to make to your code) is to use the DataContractSerializer instead. You can find more information here.

Here is a quick sample of a function using the DataContractSerializer (with your type above):

#r "System.Runtime.Serialization"

using System;
using System.Xml;
using System.Runtime.Serialization;

public static void Run(string input, TraceWriter log) 
{
   string xml = WriteObject(new App { DataB = "Test"});
   log.Info(xml);
}


[DataContract(Name = "App")]
public class App
{
    [DataMember]
    public string DataB { get; set; }
}




public static string WriteObject(App app)
{
    using (var output = new StringWriter())
    using (var writer = new XmlTextWriter(output) { Formatting = Formatting.Indented })
    {
        var serializer = new DataContractSerializer(typeof(App));
        serializer.WriteObject(writer, app);

        return output.GetStringBuilder().ToString();
    }
}