syntaxic | Open source text editor : Syntaxic

use event.target event.target.classList.toggle("filled")
or this this.classList.toggle("filled")

demo:

You're passing it as a string, not as a method. Remove the quotes and it works.

So first of all, do not mix context bounds and implicits, that is considered a bad practice; see this for more context.

Second, the order matters because if the ev comes first then the type parameters K and V are solved by the compiler before it tries to search their ClassTags.
In the other case, the compiler has no info about what K and V are so it will try to just assume anything it can find, thus finding two possible implicit ClassTags (both the one for the outer K and the outer V) creating an ambiguity.

So it's possible, I missused the centerXAnchor instead of using .centerX

Also the order in which I called each item was not correct:

I'm not entirely sure what the problem is here.

Your code mixes async and non-async code, which is usually something to avoid unless absolutely necessary (which it rarely is).

You could perhaps write the code as:

As @rici said, precedence order was missing on my code:

The following code solved the issue :

The error message that I receive says that it's possible to use Arel's sql escape to do this. Currently I am able to do something like Item.eager_load(:itemoptions).order(Arel.sql("model_id ASC, itemoptions.modeloption_id ASC"))

Also I know not part of the question, but I don't think you need the .all at the end

I personally wouldn't consider the cast to T_Concrete_X'Class so much as a syntactic trick. It's just the way to change the the view on the tagged type (type vs. type class). This "view conversion" i.e. T to T'Class (with T a tagged type) will always succeed and will not refine your view on the instance. It's not like (the more problematic) downcasting.

Regarding the two options: both are viable and it depends on your application (and probably preference) if you would take one or the other. The only difference I see is that the template pattern uses an abstract base class with abstract procedure that must be implemented by the derived type; i.e. you can't define a default implementation in your base class.

Besides the two options, you might also consider using composition instead of inheritance. Inheritance is in general less scalable once you need to vary more than one independent aspect (for now there is only one aspect, the steps, but you never know what needs to be added in the future). For this reason composition is often preferred over inheritance. Hence, you could also consider something like this:

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I assume that data is a pandas data frame. To find the methods available, I first look at the documentation for rolling():

Returns: a Window or Rolling sub-classed for the particular operation

In the left-hand menu, I see a link for Window. Clicking on this link shows all the available methods for Rolling.