Custom XML Serialization, how to write custom root element? - c#

I'm probably just doing this wrong, i know.
I'm using custom serialization and when the xml is generated it's putting the class name as the root element
Example:
<MyClassName>
<MyIntendedRootNode>
<ObjectType>
<Property1/>
<Property2/>
...
I'm invoking the serialization by calling xmlserializer.Serialize(writer,Me) so I'm sure that has something to do with it.
I've tried putting XMLRoot onto the class, but I think as vb is compiling this partial class with its aspx page, it's either overwriting this property or ignoring it entirely.
Ideally I'd like to just tell it to either throw away everything it has and use a different root element.
Anybody else do this except me?
Thanks

You can use either IXmlSerializable or use the XML attributes. I use XmlSerializer passing the root in the constructor.
var MemoryStream ms;
var customRoot = dataObject as XmlRootAttribute;
var xml = new XmlSerializer(dataObject.GetType(), customRoot);
xml.Serialize(ms, dataObject);

In ASP.NET, the actual class that is loaded is a generated class that inherits from your class. (It turns out--surprisingly--that this generated code is actually separate from the additional generated code that is combined with your code using the partial class technique. The generated class has the same name as the class you are working on, but it is in a different namespace.) Since XmlRoot is not an inherited attribute, the XmlSerializer does not see it.
I don't think there is any solution (other than modify the document after you have generated it).

Are you trying to serialize a codebehind file?
I would suggest writing a model to contain the data that needs to be saved, and then serializing that instead. Then use the appropriate XMLWriter attributes to make sure your root element is correctly named.

Or you could implement IXmlSerializable and have full control over your Xml but its a bit of extra effort just to change a root element name.

You can create a wrapper class and give that wrapper class with the name that you wish to be shown in the xml root.

Related

How do I serialize an XML collection with numbers in ItemName?

I've been scouring the web at MSDN and Google, for an answer to the following question.
How do I serialize a collection that is named as follows in c#?
<foocollection>
<fooitem1></fooitem1>
<fooitem2></fooitem2>
...
</foocollection>
I saw that you can do this in DataContract:
[CollectionDataContract(Name="foocollection", ItemName = "fooitem")]
public class FooCollection<T> : List<T> {
public FooCollection(){}
public FooCollection(T[] items){
foreach(var i in items){
Add(i);
}
}
}
The serializer is the default XML serializer from ASP.NET Web API. This code assumes that the XML posted above is coming from the client.
I have successfully serialized the above as dynamic, but dynamic isn't going to be an acceptable solution.
How would I accomplish serialization successfully using any of the below namespaces, or others, with the caveat that I can serialize to the above class? I'm willing to add extra classes as necessary to make the above work just as long as I don't have to make a class for every item in the collection.
System.ComponentModel.DataAnnotations
System.Xml.Serialization
Thank you very much in advance.
Since You didn't mention what method of xml serialization you're using, it's hard to tell, but you probably should be using DataContractSerializer in order to enable DataContract attributes. To utilize CollectionDataContractAttribute you also should have collection class that you put said attribute to, like in this example

XML deserialization - generate warning or exception on unexpected element [duplicate]

When I deserialize an XML document with XmlTextReader, a textual element for which there is no corresponding class is simply ignored.
Note: this is not about elements missing from the XML, which one requires to be present, but rather being present in the XML text, while not having an equivalent property in code.
I would have expected to get an exception because if the respective element is missing from the runtime data and I serialize it later, the resulting XML document will be different from the original one. So it's not safe to ignore it (in my real-world case I have just forgotten to define one of the 99+ classes the given document contains, and I didn't notice at first).
So is this normal and if yes, why? Can I somehow request that I want to get exceptions if elements cannot be serialized?
In the following example-XML I have purposely misspelled "MyComandElement" to illustrate the core problem:
<MyRootElement>
<MyComandElement/>
</MyRootElement>
MyRootElement.cs:
public class CommandElement {};
public class MyRootElement
{
public CommandElement MyCommandElement {get; set;}
}
Deserialization:
XmlSerializer xmlSerializer = new XmlSerializer(typeof(MyRootElement));
XmlTextReader xmlReader = new XmlTextReader(#"pgtest.xml");
MyRootElement mbs2 = (MyRootElement)xmlSerializer.Deserialize(xmlReader);
xmlReader.Close();
As I have found out by accident during further research, this problem is actually ridiculously easy to solve because...
...XmlSerializer supports events! All one has to do is to define an event handler for missing elements
void Serializer_UnknownElement(object sender, XmlElementEventArgs e)
{
throw new Exception("Unknown element "+e.Element.Name+" found in "
+e.ObjectBeingDeserialized.ToString()+" in line "
+e.LineNumber+" at position "+e.LinePosition);
}
and register the event with XmlSerializer:
xmlSerializer.UnknownElement += Serializer_UnknownElement;
The topic is treated at MSDN, where one also learns that
By default, after calling the Deserialize method, the XmlSerializer ignores XML attributes of unknown types.
Not surprisingly, there are also events for missing attributes, nodes and objects.
So is this normal and if yes, why?
Because maybe you're consuming someone else's XML document and whilst they define 300 different elements within their XML, you only care about two. Should you be forced to create classes for all of their elements and deserialize all of them just to be able to access the two you care about?
Or perhaps you're working with a system that is going to be in flux over time. You're writing code that consumes today's XML and if new elements/attributes are introduced later, they shouldn't stop your tested and deployed code from being able to continue to consume those parts of the XML that they do understand (Insert caveat here that, hopefully, if you're in such a situation, you/the XML author don't introduce elements later which it is critical to understand to cope with the document correctly).
These are two sides of the same coin of why it can be desirable for the system not to blow up if it encounters unexpected parts within the XML document it's being asked to deserialize.

How can RestSharp deserialize this Xml?

Is it possible to get RestSharp to deserialize this Xml snippet, into a single class, instead of two classes?
<shippingInfo>
<shippingServiceCost currencyId="AUD">58.02</shippingServiceCost>
<shippingType>Flat</shippingType>
<shipToLocations>Worldwide</shipToLocations>
</shippingInfo>
Notice the first element shippingServiceCost ? it has an attribute there. Normally, I would just create a child class called ShippingServiceCost and add two properties in there: CurrentId and Value.
But it it possible to have the CurrencyId value in a property, in the main class ShippingInfo ?
The way I would do it, could be:
crafting a small XSLT file that does what you want to transform the orginal xml to the new structure
extend the default RestSharp XmlSerializer to apply the XSLT transformation after the normal serialization output
register the new XmlSerializer to the restsharp client

Asp.net XML to objects

I have a XML file, with a structure like
<items>
<item>
<someDetail>
A value here
</someDetail>
</item>
<item>
<someDetail>
Another value here
</someDetail>
</item>
</items>
With multiple items in it.
I want to deserialize the XML on session start ideally, to turn the XML data to objects based on a class (c# asp.net 4)
I have tried several ways with either no success, or a solution which seems clunky and inelegant.
What would people suggest?
I have tried using the xsd.exe tool, and have tried with the xml reader class, as well as usin XElement class to loop through the xml and then create new someObject(props).
These maybe the best and/or only way, but with it being so easy for database sources using the entities framework, I wondered if there was a similar way to do the same but from a xml source.
The best way to deserialize XML it to create a class that corresponds to the XML structure into which the XML data will deserialize.
The latest serialization technology uses Data Contracts and the DataContractSerializer.
You decorate the class I mentioned above with DataMember and DataItem attributes and user the serializer to deserialize.
I'd use directly the .NET XML serialization - classes declarations:
public class Item {
[XmlElement("someDetail")]
public string SomeDetail;
} // class Item
[XmlRoot("items")]
public class MyData {
[XmlElement("item")]
public List<Item> Items;
public static MyData Deserialize(Stream source)
{
XmlSerializer serializer = new XmlSerializer(typeof(MyData));
return serializer.Deserialize(source) as MyData;
} // Deserialize
} // class MyData
and then to read the XML:
using (FileStream fs = new FileStream(#"c:\temp\items.xml", FileMode.Open, FileAccess.Read)) {
MyData myData = MyData.Deserialize(fs);
}
I've concluded is there is not simple unified mechanism (probably due to the inherent complexities involved with non trivial cases - this question always crops up in the context of simple scenarios like your example xml).
Xml serialization is pretty easy to use. For your example, you would just have to create a class to contain a items and another class for the actual item. You might have to apply some attributes to get everything to work correctly, but the coding will not be much. Then it's as easy as -
var serializer = new XmlSerializer(typeof(ItemsContainer));
var items = serializer.Deserialize(...) as ItemsContainer;
Datasets are sometimes considered "yesterday tech" but I use them when they solve the problem well, and you can leverage the designer. The generated code is not pretty but the bottom line is you can persist to a database via the auto generated adapters and to XML using a method right on the data set. You can read it in this way as well.
XSD.exe isn't that bad once you get used to it. I printed the help to a text file and included it in my solutions for a while. When you use the /c option to create classes, you get clean code that can be used with the XmlSerialzier.
Visual Studio 2010 (maybe other versions too) has an XML menu which appears when you have an Xml file open and from that you can also generate an XSD from sample Xml. So in a couple of steps you could take your example xml and generate the XSD, then run it through XSD.exe and use the generated classes with a couple of lines XmlSerializer code... it feels like a lot of machinations but you get used to it.

XmlSerializer.Deserialize - ignore unnecessary elements?

I've got an XSD schema which I've generated a class for using xsd.exe, and I'm trying to use XmlSerializer.Deserialize to create an instance of that class from an XML file that is supposed to conform to the XSD schema. Unfortunately the XML file has some extra elements that the schema is not expecting, which causes a System.InvalidOperationException to be thrown from Deserialize.
I've tried adding <xs:any> elements to my schema but this doesn't seem to make any difference.
My question is: is there any way to get XmlSerializer.Deserialize to ignore these extra elements?
I usually add extra properties or fields to all entity classes to pick up extra elements and attributes, looking something like the code below:
[XmlAnyAttribute]
public XmlAttribute[] AnyAttributes;
[XmlAnyElement]
public XmlElement[] AnyElements;
Depending on the complexity of your generated code, you may not find hand-inserting this code on every entity appealing. Perhaps only-slightly-less-tedious is defining these attributes in a base class and ensuring all entities inherit the base.
To give fair attribution, I was first introduced to this pattern when reading the source code for DasBlog.
I don't think there is an option to do this. You either have to fix the schema or manually modify the code generated by xsd.exe to allow the XML to be deserialized. You can also try to open the XML document + schema in Visual Studio or any other XML editor with schema support to either fix the schema or the XML document.

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