[System.Xml.Serialization.XmlRootAttribute("player", IsNullable = false)]
public class Player
{
...
}
Creating and serializing new Player() whitout setting any properties gives me
the XML Element<player/> but I would like to get <player></player>.
As far as XML is concerned, <player/> is equivalent to <player></player>. See XML spec here related to this.
If you still need to have <player></player> then you are doing something wrong.
I am assuming your problem is when you read an empty node you are crashing. You should always check for empty elements before trying to read any elements/attributes.
They should be considered equivalent values. However, if you need then working with a custom XmlWriter may be your best bet, as described here in the answer to a similar question here:
http://social.msdn.microsoft.com/Forums/en-US/xmlandnetfx/thread/979315cf-6727-4979-a554-316218ab8b24/
Related
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
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.
Hi I'm quite new to C# and I'm trying to make a text editor that saves and loads Plaintext formats. I've used NewtonSoft.Json NuGet package, but I'm getting an error. I've stated a string called textToLoad, which is set to a JsonConvert.DeserializeObject. Only thing is, it says it can't convert an object to a string! I tried toString(); but it still had the same error.
It is kind of hard without the code. The process of serializing and deserializing is pretty straight forward using Json.Net. So this is an example from their documentation:
YourType yourObject= new YourType();
yourObject.Property="something";
string output = JsonConvert.SerializeObject(yourObject);
//For some reason you want this to be string, but is the type you serialized in the first place
YourType textToLoad= JsonConvert.DeserializeObject<YourType>(output);
This outlines the basic works of serializing and deserializing. But we don't really know the details of your implementation.
Hope it helps.
You can't deserialize into a string like that. At simplest form you started with JSON in the form of:
{ value: "someString" }
If you want something out of it, you must deserialize and then get the value from it.
dynamic foo = JsonConvert.DeserializeObject<dynamic>(theJson);
var textToLoad = foo.value.ToString();
You must deserialize to something in order to inspect and get properties from it.
[Edit] - Perhaps I'm not understanding. But if you share code, I'll update my answer.
I don't have experience with this so perhaps I'm using the wrong terminology.
The scenario is this: I'm serializing a class instance to a file using the code from https://stackoverflow.com/a/12309136/939213 . But at some point I might want to change the class a bit, so I would like to insert an int into the file telling the program what version of the class this is.
I tried serializing the int and the class into the same file but discovered that's impossible, so I'm now thinking of having an int property in the class for that, and reading that first, in order to know what class should be deserialized.
So how do I read that int alone?
EDIT: For example, to read the myInt in this:
<MyClass xml...>
<myInt>10</myInt>
<myString>abc</myString>
</MyClass>
You need to provide some example xml if you want a specific answer, otherwise you can check out Linq-To-Xml for more info.
A comment lead me to a solution:
XDocument xdoc = XDocument.Load(path);
int answer = (int)xdoc.Descendants("myInt").ToArray()[0];
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.