Add OnError<TData>

[NooNameR]

Would be nice to see OnError<TData> as well
And consider to have OnError(Action<ICakeContext>) and OnError<TData>(Action<TData,ICakeContext>)

[devlead]

Relates to Gitter discussion https://gitter.im/cake-build/cake?at=5c385c932e25e453d76409f9

Is there any plans to do OnError?

Suggested current workaround https://gitter.im/cake-build/cake?at=5c3883d883c7e37765510bc9

Example:

public class BuildData
{
    public bool HasError { get; set; }
}

Setup(context=>new BuildData());

Task("Boom")
    .Does(()=>throw new Exception("Boom"))
    .OnError(exception => {
            Error(exception);
            var data = Context.Data.Get<BuildData>();
            data.HasError = true;
        });

Teardown<BuildData>((teardownContext, data) =>
{
    if (data.HasError)
    {
        Error("There was errors.");
    }
    else
    {
        Information("There was no errors");
    }
});

RunTarget("Boom");

Will output

[yansklyarenko]

@devlead Could you please elaborate on this one?

As far as I understand, when the requested method overload is implemented, the sample above will transform to this:

public class BuildData
{
    public bool HasError { get; set; }
}

Setup(context=>new BuildData());

Task("Boom")
    .Does(()=>throw new Exception("Boom"))
    .OnError<BuildData>((exception, data) => {
            Error(exception);
            data.HasError = true;
        });

Teardown<BuildData>((teardownContext, data) =>
{
    if (data.HasError)
    {
        Error("There was errors.");
    }
    else
    {
        Information("There was no errors");
    }
});

RunTarget("Boom");

It means there must be a method OnError<TData>(this CakeTaskBuilder builder, Action<Exception, TData> errorHandler), which should end up setting ErrorHandler property of the CakeTask to some value of type Action<Exception>. But where do I get the data from? There's no global Context like in the sample above, nor there's a parameter of type ICakeContext.

I investigated the Does functionality which looks similar and has the necessary overload. However, it also has ICakeContext parameter and gets TData from there when it's needed.

I might be missing something obvious, but it doesn't match in my head right now... I would appreciate some hint. Thanks!

[devlead]

There's a global ICakeContext Context property available in non static methods and delegates in scripts.

So Context.Data.Get<BuildData>(); will work as long as your not in a class or static method/delegate.

But to sort a OnError<BuildData> it would require a little bit more work internally.

[yansklyarenko]

But to sort a OnError<BuildData> it would require a little bit more work internally.

Yep, that's clear. I'd like to take over this challenge and would appreciate some hint regarding what that work internally could be. Is there a similar logic in the project I can leverage to understand what should be changed?

[yansklyarenko]

@devlead I think I got your point. I would appreciate your review.