Using JAXB in Java it is easy to generate from a xml schema file a set of Java classes that xml conforming to that schema can be deserialized to.
Is there some C# equivalent of JAXB? I know that Linq can serialize and deserialize classes to/from xml files. But how can I generate C# classes from xml schema file and then use this classes with linq?
If you're using Visual Studio, try the XML Schema Definition Tool. It takes your schema definitions and produces C# classes -- or it can go the other way and produce schema definitions from classes. It also has a number of other XML-related transformations.
There is a better tool from Microsoft called XsdObjectGen, the XSD Object Code Generator. It is like xsd.exe, but better. Also free, it is not part of the .NET SDK, but is a separate download.
Also see the SO question: XSDObjectGen vs Xsd.exe
Look into using DataSet. It's a bit of a different concept from using "Java Beans". The entire XML document is treated hierarchical set of tables all in a single class. The good part is that theory of encapsulation for OOP is actually enforced. Wow, Microsoft got something right that Sun pooched.
Anyway. You can also look at typed DataSet's if you want make things more interesting. I've used this on major projects with great success.
Related
I have to implement support for ISO20022 file format in our application and the "xsd.exe" tool provided with Visual Studio 2022 is frustratingly inadequate.
The most frustrating point is the lake of proper support for nullable types in the generated code: when a XML element is marked as "optional", the generated code should properly generate a nullable member in the target class. Instead, it generates a mess of two fields (MemberName and MemberNameSpecified}.
This makes the code working with the result way less readable than it should and more error prone.
Another sore point is the missing support for related schemas: various versions of the ISO2022 XML schema files exists and financial entities typically do not support them all. Since the xsd.exe tool does not (to my knowledge) allow mappinh of multiple XSD and namespaces into a single C# namespace, identical elements in the spefifications generates identical objects but in different C# namespace. This force us to cut and paste identical code for identical objects that are in different namespaces.
Is there a way to get XSD.exe to generate a "modern" class from an XML shema?
Is there another tool that could fit the bill (paid tools are ok if they get the job done).
There are 2 really good open source and free options for C#/.NET (including Core + Framework):
https://github.com/mamift/LinqToXsdCore
Back in 2008, Microsoft did work on improving XSd.exe, and they shipped a successor tool called LinqToXsd, which improves upon XSD.exe in many ways. It has been ported over to .NET Core and does support multiple namespaces (importing + including), and adding #nullable enable annotations to the generated code. This tool produces .NET Standard 2 code that is very different from XSD.exe, and tries to model the schema more closely than XSD.exe. See some sample code here.
https://github.com/mganss/XmlSchemaClassGenerator
This project is newer, and has better support for #nullables through the AllowNullAttribute and MaybeNullAttribute instead of just the #nullable pragma. This project can also generate interfaces from element and attribute groups, which is nifty when you need it, which neither XSD.exe nor LinqToXsdCore supports. This tool also generates code that looks closer to what XSD.exe gives you.
You might want to fiddle with both of them before making a decision. But I recommend using XmlSchemaClassGenerator, unless you have legacy code based on the old .NET Framework version of LinqToXsd, then LinqToXsdCore is more compatible as it is a straight-forward port.
I am using XSD.exe to convert a pretty complex XML-Schema (XSD-file) to C# Classes. I am then using XmlSerializer to read XML into memory and work with the data.
In the future, the XSD will change. So there will be a new version. I will have to create a new cs file with XSD.exe. But I still want to support the old versions of XML files as well.
What is the best way to go about this and support both the old and new versions of XML files? Obviously, the classes XSD.exe creates will have the same names. So I can't really just generate another cs file in parallel with XSD.exe.
Any ideas are welcome. Thanks in advance!
XML Data Binding has the advantage of enabling you to code against strongly typed classes rather than untyped nodes, but this can make versioning tricky.
Information about this can be found in the 'Schema Versioning' section of Liquid XML Data Binder 2021 - Getting Started documentation.
Data binding technologies (that convert XSD definitions into types in a strongly-typed programming language) are an absolute pain when the schema is large, complex, or changing. My strong advice would be, find a different approach. I've earned a lot of consulting money helping people dig themselves out of this hole.
Use technologies that are better at coping with change and variety. XSLT, XQuery, LINQ, or even DOM if you must. XSLT and XQuery come with schema-awareness as an option so you can get some of the benefits (having your program code checked against the schema) without the heavy price of rebuilding and retesting your application every time there's a change.
Thank you for your answers.
For now, I placed the Code generated by XSD.exe in separate Namespaces and have them derive from a base class.
Like this, I can use either one or the other Class for generating/reading the XML. It appears to be working for me right now, as the Schema will not change without a new Version. Any changes made will be put into a new Version.
I have XSD file, which seems rather complex (I am very new to working with XSD).
My task is to create a program, which would generate XML files based on the XSD schema (in a more detail - we will get a CSV file with the data and these need to be serialized into a XML). I did a research and tried various techniques of generating C# class from the XSD file, where the most 'compact' was xsd2code plugin for Visual Studio.
Nonetheless, this plugin has generated over 7,000 lines of code which quite shocked me as it was just one giant mess (for me).
My question now is - is there a better way (or maybe some switch I forgot to check) which will generate rather compact C# class? If not, then what is the next step that people have to do once they get C# class? Do they have to additional manual post processing so that the file is more 'programmer-friendly', or ...?
Thank you for your guidance; any help or tip will be highly appreciated!
I have this XML file, and I want to deserialize it to an object. But I don't want to type its class definition. There is any tool that can create the C# code of the class for me, inferring the data types from sample data?
Yes. Out of the box, you can use xsd.exe to generate XSD files from XML. You can also use this tool to generate classes from XSD files.
The code it produces is limited, which is why there are some third party tools that have stepped in.
Two of those tools include LiquidXML (costs money) and CodeXS (free). We use CodeXS, because it is free and extensible. We have extended it quite a bit.
EDIT:
CodeXS has an online tool. Just give it an XSD. It produces your classes for you.
They also have a command-line tool (source code) which is extensible and doesn't require you to send the XSD to their web service. We use it as a pre-build step.
Liquid Technologies has a good tool for this purpose (Data binding) http://www.liquid-technologies.com/. You'll really need to define a schema though instead of letting such a tool "infer" it from sample data.
One of the benefits of Liquid that we've found is that it can also generate code for Java, C++, C#, VBA etc. All very consistent.
Check out LINQ-to-XSD
It requires that you write a schema for your XML but then it's pretty good about a direct translation to objects.
Is there something available that could help me convert a XSD into SQL relational tables? The XSD is rather big (in my world anyway) and I could save time and boring typing if something pushed me ahead rather than starting from scratch.
The XSD is here if you want to have a look. It's a standardized/localized format to exchange MSDS.
Altova's XML Spy has a feature that will generate SQL DDL Script from an XSD file. XML Spy will cost you some money though.
Interestingly enough, a developer used a really clever trick of using an XSLT translation to create the DDL script from an XSD file. They have outlined it in two parts here and here.
I might have to try this out myself for future use...
EDIT: Just found this question asked previously here...
There is a command-line tool called XSD2DB, that generates database from xsd-files, available at sourceforge.
For more info: please refer to this existing question How can I create database tables from XSD files?
You can use an XSLT transform. See, for example, here: Generating SQL from XSD and XSL stylesheets with XSLT.
Microsoft has a command-line tool for performing XSLT transformations: Microsoft Command-Line tool for XSLT.
It is also easy to integrate the transforms into a build process using MSBuild or Grunt.
Here is the reference for the Microsoft documentation: XML Standards Reference, including XSD, XSLT, etc.