Improve XAML by removing noise

Is your feature request related to a problem? Please describe.

I’m always frustrated when trying to explain XAML to a web developer.

Describe the solution you’d like

Remove all the unnecessary noise from XAML and make it friendlier to everyone.

Describe alternatives you’ve considered

None at the time.

Additional context

So, this is the XAML for an Avalonia Hello World:

<Window xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
        x:Class="MyApp.Window1"
        Title="Window1">
  Welcome to Avalonia!
</Window>

That’s a lot of noise to explain to somebody who has never used Avalonia nor WPF. It would be awesome if it was just:

<Window Title="Window1">
  Welcome to Avalonia!
</Window>

Since none of the other stuff is really required.

• xmlns and xmlns:x should really be implicit for every XAML file ever, since they’re pretty much required.
• xmlns:d and xmlns:mc are designer-specific concerns that don’t really belong into production source code. The designer / previewer could handle this implicitly.
• x:Class has 2 pieces of information:
  • the namespace could be implicitly derived by the location of the XAML file relative to the root of the project (following C# namespacing convention). It could still be explicitly added manually to override the convention if required.
  • the class name could be implicitly derived from the XAML file name.

Also: it would be awesome if custom and user controls in an assembly where implicitly mapped to the root namespace instead of having to define a custom XAML namespace for them.

[cesarchefinho]

I dont like #2502

It is not better than this proposal, 2502 is flutter or qml or other strange thing but not xaml

this proposal maintain xaml and only simplifies markup, improving developper experience.

[ichthus1604]

Changing it would make it even more difficult for developers coming from WPF or MAUI or any other framework using XAML

I strongly disagree.

There is nothing “more difficult” in this:

<Window Title="Window1">
  Welcome to Avalonia!
</Window>

compared to this:

<Window xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
        x:Class="MyApp.Window1"
        Title="Window1">
  Welcome to Avalonia!
</Window>

Quite the contrary, all that useless noise makes me really want to quit XAML and learn HTML and React just to be able to write markup similar to the first example.

Nothing is more frustrating then to read tons of documentation pages to get some basics done

Again, there is absolutely no need to read any documentation to understand my first example. Quite the contrary, people need to read tons of documentation just to be able to understand a simple Hello World app with all that amount of useless noise and unnecessary complexity in the markup. Let alone anything more complex.

users who start with Avalonia and then switch to WPF/MAUI

Sorry, WPF is legacy and MAUI is honestly unusable and full of bugs. I personally couldn’t care less about any of that.

Also, as mentioned above, my proposal includes an MSBuildFlag (let’s call it <UseLegacyXaml>True</UseLegacyXaml> if you want / need to use legacy XAML.

cause conflicts if a name of a class exists both

This does not happen in practice, and if it does the compiler should fail to build that specific case, which is 0.00001% compared to the 99.9999% of times I do not have any conflict but still I’m forced to explicitly specify everything manually, which again leads to useless noise.

Improvements should make developing more easier and not just “looks better because less code”.

My proposal makes development substantially easier by avoiding unnecessary details such as namespaces that are totally not relevant when writing, nor maintaining code. This noise results in cognitive load, and cognitive load makes development substantially harder and more painful.

even added a checkbox

Yes. People are free to write legacy code with legacy idioms all they want. I personally want a way forward that doesn’t force me to write code like it was 2006.