Fixing Mvvm Commands - Making Hot Tuna better - @XamlDude bags a Tuna flavored Badge of Awesomeness

Last week @xamldude posted an interesting blog post on ICommands might be 'improved' -

http://xamlblog.tumblr.com/post/46187145555/fixing-mvvm-part-1-commands

Not everyone agreed with the post - a few notable names said it was an already solved problem - that, code snippets, for example negated the need for this.

However....

....

... I loved the idea.

So, MvvmCross v3 is going to ship with a new class - MvxCommandCollection

This class allows you to write and expose your ICommands as methods.

	public void Init()
	{
	Commands =
	new MvxCommandCollectionBuilder()
	.BuildCollectionFor(this);
	}
	public IMvxCommandCollection Commands { get; private set; }
	public void SearchCommand()
	{
	if (SearchText == "javascript")
	return;
	if (string.IsNullOrWhiteSpace(SearchText))
	return;
	ShowViewModel<TwitterViewModel>(new { searchTerm = SearchText });
	}
	public void PickRandomCommand()
	{
	var items = new[] { "MvvmCross", "WP7", "MonoTouch", "MonoDroid", "mvvm", "kittens" };
	var r = new Random();
	var originalText = SearchText;
	var newText = originalText;
	while (originalText == newText)
	{
	var which = r.Next(items.Length);
	newText = items[which];
	}
	SearchText = newText;
	}

view raw CommandsSnippet.cs hosted with ❤ by GitHub

After you've done this, then the commands can be accessed in XAML or AXML using markup like:

	<TextView
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:text="Random"
	android:textSize="40dp"
	local:MvxBind="Click Commands[PickRandom]"
	/>
	<Button
	android:layout_width="fill_parent"
	android:layout_height="wrap_content"
	android:text="Go"
	local:MvxBind="Click Commands[Search]"
	/>

view raw commands.xml hosted with ❤ by GitHub

This approach won't be to everyone's tastes - but I love it - it gives users the choice to just name methods ending with 'Command' and these will automatically translate to ICommand's

Behind the scene's there's also more going on too - e.g.  you can use parameterised commands, and you can use CanExecuteCommandName properties to enable/disable the Commands too. I will try to explain that more fully another day...

For now... @xamldude this was an awesome post - there's only one way to say 'thank you' - with a badge of Hot Tuna MvvmCross awesomeness:

Awesome @xamldude Awesome!