XmlTextAttribute Support (Rudimentary)

[justeff]

It seems like that XmlTyp(AnonymousType = true) is not supported.

        public class ClassA
        {
            public string ElementA { get; set; } = "TextA";
            public ClassB B { get; set; } = new ClassB();
        }
        
        [XmlType(AnonymousType = true)]
        public class ClassB
        {
            public string ElementB { get; set; } = "TextB";
        }

I want to prevent <B><ElementB>TextB</ElementB></B> and just get <ElementB>TextB</ElementB> inside ClassA. Is there another way to achieve this? I have to say, I don't like the standard Xml Serializer solution, because if I need a class C which should have Class B fully inside and not just his members, then I have to create a duplicate class for B but without the "AnonymousType" tag, that's why I would favour a member tag like XmlElement to be more flexible.

[Mike-E-angelo]

Ah... well, unfortunately, we do not offer anything out of the box.

Now, if there is only one property you need this for per class, then you could create an extension that could make a content property ala Xaml's ContentPropertyAttribute.

This is of course something that I have been meaning to do because it makes a good extension story. Unfortunately it's not in there, but we'll strive to make it for v3 (I really hate punting work, sorry!).

Of course, I am of the opinion that having property names is a nice thing to have in your serialized object graph. 😇

[justeff]

Well, you do not need to apologize :), I thought about making my own Xml Serializer after I created my own XSD code generator, but I guess it would be better to help you with your framework. I only have 2 rare cases where I would favour this option. In the UML model, I have an aggregation and in the XSD file it's just a group reference and I thought it would be nice to hide the schema definition from the user and just give him the UML representation (give him the group reference as the underlying class, but resolve its members like if they belong to the root class (ClassA) to be compatible with the XSD ;)

[Mike-E-angelo]

Ah cool... sure if you manage to build an extension we will gladly accept and review any PRs you have. :) Do note that v2 (current version) is pretty much in release mode. We do have a v3 planned but it's pretty much a rewrite.

As for XML types... we do have our own system and derive it from CLR types, or the types defined in the member, if that makes sense.

[justeff]

Do you have an example for the XML types?

Because [XmlText(DataType = "dateTime")] public DateTime Value { get; set; } = DateTime.Now; and [XmlText(DataType = "date")] public DateTime Value { get; set; } = DateTime.Now; is not working for me. I would expect different output streams.

[Mike-E-angelo]

Ah, so what I was saying is that we have our own type system in this regard. We always emit by default the value of a DateTime instance based on its registered converter, which is the result of XmlConvert.ToDateTime. You can see this here.

So, by default, all DateTimes and DateTimeOffsets look the same, if that makes sense.

If you want, this would be a good place to use a custom serializer on a member to yield the result you are looking to achieve. :) Actually, it would be an extension that would work in conjunction with custom member serializers.

I should point out that while we do not support every legacy/classic feature, the scope and intent of ExtendedXmlSerializer is to serialize/deserialize object graphs, rather than interop with other external data sources (which was classic XmlSerializer's primary concern, IMO). Formatting text such as this is usually rooted in having to account for an external schema of some sort. In this case, I would recommend using XSLT to get the data prepared correctly.

[justeff]

What's about [XmlText]? Seems like I have to stick with the standard XmlSerializer? :(

[Mike-E-angelo]

I guess I am not too familiar with XmlText. Are you looking to format your DateTime in a specific way? This can be done with extensions but there is nothing built yet for it, I'm afraid.

[Mike-E-angelo]

Ah alright... so it seems that this is indeed a mechanism to pull in content from an element and assign it to a property on a class. Much like ContentPropertyAttribute as denoted earlier. I am assuming the dateTime formats from the DataType property are used to properly read it in.

So what this is IMO is a ContentProperty, which could be read in via metadata (classic XmlTextAttribute) or via the ConfigurationContainer.

Maybe something like new ConfigurationContainer().Type<Subject>().Content(x => x.Property) and/or new ConfigurationContainer().Type<Subject>().Member(x => x.Property).AsContent().

Is there anything specific/magical about the XmlText that is missing here? I think everything else is covered by EXS's type system.

[justeff]

Yeah, a content property and no it's not DateTime, most of the time it's just a string oder List<string>. I have over 300 generated classes and about 70 of them use this kind of property. So using ConfigurationCointer is no soultion for me and XmlText or XmlTextAttribute is not working, The property is treated like a regular element property ... hmm. YAX can handle this, but it has problems with collections of base classes (you don't have it). XmlSerializer can handle this all, but it's slow and you have set a lot of additional meta data informations when using inheritance and this is quite odd. Thanks for your help.

[Mike-E-angelo]

OK @justeff I ACCEPT YOUR CHALLENGE!!! 😆 Well, more like I feel your pain. I myself have been spending the past week going through and trying to get all my identities aligned between GOOG and MSFT... and there is not a single chat solution that I am happy with between the two. This is especially perplexing as GOOG has like 5 different chat applications and each one of them does something good, but none of them do it exactly right.

So I did some research on this and I cannot find an example of XmlText used as a string list. Do you have a quick example you can share? I am mostly interested in the xml output.

[justeff]

Sure.

    public class ClassWithMixedContent
    {
        [XmlText] public List<string> Value;
    }

    class TestClass
    {
        static void Main(string[] args)
        {
            var obj = new ClassWithMixedContent();
            obj.Value = new List<string> {"string1", "string2"};
            
            var sw = new System.IO.StringWriter();
            var serializer = new XmlSerializer(typeof(ClassWithMixedContent)); 
            serializer.Serialize(sw, obj);
            var xmlText = sw.ToString();
            Console.WriteLine(xmlText);
            var stringReader = new System.IO.StringReader(xmlText);
            var obj2 = serializer.Deserialize(stringReader) as ClassWithMixedContent ;
        }
    }

I got this originally from xsd.exe (or xsd2code). In the MS doc you'll find it too. Thr elements of the string list gets concatenated and if you deserilaize it back you just get one big string ... but that's ok.

[Mike-E-angelo]

Wow, you were not kidding:

<?xml version="1.0" encoding="utf-16"?>
<ClassWithMixedContent xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">string1string2</ClassWithMixedContent>

That might be OK with you but that is not OK with me. 😆

If possible, I would rather maintain the integrity of the graph as emitted from memory.

Are you OK with having this emit the strings as serialized entities? Something like:

<?xml version="1.0" encoding="utf-16"?>
<ClassWithMixedContent xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><string>string1</string><string>string2</string></ClassWithMixedContent>

Essentially what we would be doing instead is checking if there is a content property assigned to a type, and if there is internal content, route it to the serializer of the type of the content property to get it serialized and back.

[justeff]

Just realized, list string makes no sense for me. The XML is standardized, if I get it from an external source it will be just one big string haha. I need only a content property then :)

[Mike-E-angelo]

OK COOL... let's see what I can do. 👍

[Mike-E-angelo]

Alright... I checked this out and I think I have a reasonable path forward here. I've got some tasks that I have to wrap up for today, but I am going to aim to have this available for you by EOD tomorrow if that works for you. Assuming there aren't any super-gotchas that impede the path, that is. 😇