Introducing the XML Assembly Generator

OK, so I'm back... with a gift to the world. For the last month or so I've been working on a project in my spare time that has already been a great help in my architecture and development work. About a month ago I got COMPLETELY fed up with writing code manually and I've always despised UML and graphical code generation systems (like Visio for Enterprise Architects-- I hate Visio anyhow!), but I'm completely addicted to XML and have been for years. What I wanted (demanded!) was a declarative (NON GUI!!!!!) programming tool that allows brainstorms/architectures/projects to be written in pure XML, so that I can think in concepts without having to work directly with code. So, I decided that it was about time that I create a system that will compile a XAML-like structure to a complete VS2005/C# project.

The system has already been a tremendous help to me. In fact, when I got the initial features of the system setup, I used it to create the rest of the system. This helped speed up development because I think in terms of trees, branches organization, and XML. When I was architecting the internal components of the compiler, I was doing all my work in XML using my XAML-like format. Then, when I got a design I kinda liked, I would run it through my compiler (at the time just a console application) and VOOM I got my C# project.

So, as of today, I'm releasing to the public in alpha form under the project-name "XAG" or "XML Assembly Generator". I considered the project-name "XAC" for "XML Assembly Compiler" as it's more of a compiler than anything else... but "XAC"? That's a real name and I found that beyond lame.

Though there is a complete documentation page linked from the XAG start page, here are some of the features that XAG provides.

• Creation of classes
• Creation of structs
• Creation of enumerations
• Creation of delegates
• Creation of interfaces
• Creation of physical folders
• Creation of custom attributes
• Creation of type aliases ("using A = B;")
• Automatic Interface Implementation
• Usage of Polymorphism
• Strongly-linked objects (the resource "x:Key" subsystem)
• Inclusion of properties
• Inclusion of fields
• Inclusion of constructors
• Inclusion of methods
• Inclusion of events
• Auto generated constructors for properties
• Static members
• ref and out parameters
• Inline instantiation of properties and fields
• Inclusion of app.config data

I would like to point out a few special features of the system besides what should be obvious. First, I tried to make the syntax as close to XAML as possible, including the concept of resources. So, not only can you create types, but you can strongly-link types together just like you can do in XAML with resources. For example, you can create a class called "Item" and give it a key of "MyItem01" then you can create another class and declare a property using the type referring to the key "MyItem01". XAG will do all the magic for you in finding the real name of the type. This same concept is used for many things including inheritance, interface implementation, and aliasing generics. This helps you keep your structures strongly-linked, so you can ensure that when you want to inherit from a specific class named "MyClass" you get the specific one you want, not another one with the same name, but in a different name space. This also decouples the name of the type from the key. So you can rename the class all day long and not have to update any references. As a side note, just like with WPF/XAML, in order to access a resource, you have to first declare it. I don't think that's too much to ask.

Second, have you ever created a type with multiple properties and then had to create a constructor to set all the properties? I hate doing that. I appreciate it when it's done (who isn't frustrated at the WPF guys forgetting to do that on their UIElements!?), but still... it just seems like work that should be done for you. C# 3.0 makes this work easier... but XAG simplifies this for you today. So, when you want to create a class with properties that has a constructor to set the properties, simply create the class and the properties and set AutoGenerateConstructorsByProperties to true and BAM, your type will magically have a constructor (in addition to the parameterless one) that maps parameters to properties.

Third, when compiling the XML to C# (or VB2005 or IL or whatever the destination is--given I add those abilities), XAG looks for compliance to many coding practices. For example, if you try to set a class field to public, the compiler will give a warning and tell you it's changing it to private. I personally hate it when people write code that doesn't obey the .NET coding laws. So, I'm not allowing some of the most common things that lead to screw ups. Also, structs have many rules that are enforced. In fact, structs have more rules enforced than all other types combined. This is not so much for compliance to the .NET coding laws, but, rather, because structs just have more rules than classes. For example, say you have a struct with three instance Int32 fields and you want a constructor. Well, first off, you can't have a parameterless constructor and secondly, if you have a constructor at all, you have to initialize all the fields before control leaves that constructor. When creating constructors, XAG knows about your fields and initializes them for you.

Here are some sample XML documents that will compile to VS2005 projects:

The simplest ever:

<assembly />

Something a bit more interesting:

<Assembly xmlns:x=" http://www.jampadtechnology.com/xag/2006/11/ ">
  <MyClass x:Key="MyClass" Type="Class" Namespace="ClassNamespace" />
</Assembly>

OK, that wasn't interesting at all... So, here's one that should explain things a bit better:

<Assembly xmlns:x=" http://www.jampadtechnology.com/xag/2006/11/">
  <MyClass x:Key="MyClass"
             Type="Class"
             AutoGenerateConstructorsByProperties="True"
             Namespace="ClassNamespace">
    <Properties>
      <Id Type="Int32" />
      <Name Type="String" />
    </Properties>
  </MyClass>

  <MyOtherClass Type="Class" AccessModifier="Public" Inherits="{Type MyClass}" Namespace="ClassNamespace" />

</Assembly>

This last one creates a project with two classes, one inheriting from the other. The first class has two properties and two constructors, one which is parameterless (as you should always have!) and one which takes two parameters and sets them to their respective properties.

Looking at that, you may think it's too much overhead. Well, this isn't a sissy C# file creator. This thing actually creates the entire project and returns it to you as a single zip file. So, even if you wanted to start a new project, this system will help you tremendously. Simply open the XAG screen, select a template (optional), type in your code, hit Create Project, and you'll immediately get a ZIP file containing all folders, all files, an AssemblyInfo.cs file, and the project file. You will have everything you need to start your solution or to continue your solution by simply adding the XAG project to your existence solution.

The XAG website also currently has a few tools you may find useful. Not only can you use the initial screen to create your XAG projects, but you can also use it to check for well-formed XML and also to format your XML. The entire website is Ajax based, so responsiveness is unsurpassed. As a side note, in case anyone is wondering, I did all the Ajax code manually as I find it much more efficient than using Atlas, however... I am using Atlas for web service calls to the main compilation server.

As a warning, I'm still cleaning up the website (it's alpha!) so there may be problems in selling all compilation errors. I'm also redoing major parts of how compiler warnings are displayed, so, for now, there might not be any compiler warnings (it depends on when you look at the site!) Ideally, I would like the system to give a list of compiler errors and warnings to the end user (you!) It does in the console version, but I've yet to completely add that to the website.

In the future I'll probably be modifying the syntax a bit (and therefore adding a release notes/change log here) and adding a few features and simplifications that I've been meaning to add for a while. For example, I wrote a much more powerful subsystem for generics, but decided that I should hold off on a public release of that to version 2.0. I will also be monitoring the exception logs and fixing bugs as they come up. I'm sure I'll be adding a ton of "if(v != null)" in this initial release.

You can access this application at http://www.jampadtechnology.com/xag/. You can hit the intro link to see how it works, but it's fairly obvious. Most importantly, PLEASE SKIM THE DOCUMENTATION. I didn't say read it. Only super-geeks with no lives READ documentation. Just skim it and take in the overall idea and syntax. Lastly, please feel free to use any examples in the documentation, documents in the samples section (which I will be expanding upon), or provided templates to start or assist in your usage of the system.

Links

• XML Assembly Generator
• Documentation