Throw exception if aggregate widget/shape renderers could not be found

[dantleech]

Currentlty the "aggregate" shape painters and widget renderers iterate over all of the painters/renderers and each painter/renderer will return early if it's "not interested".

Pros:

• These things can act as filters

Cons:

• More iterations than necessary (although this is really not significant)
• More annoyingly: Silently "failing" if no painter/renderer was found for a widget.

It's more of a development issue than a user issue however.l

[KennedyTedesco]

I was thinking about adding a new method to the WidgetRenderer interface:

// WidgetRenderer
public function supports(Widget $widget): bool;

// GaugeRenderer
final class GaugeRenderer implements WidgetRenderer
{
    public function supports(Widget $widget): bool
    {
        return $widget instanceof GaugeWidget;
    }

    // ...
}

Then, in AggregateWidgetRenderer, we can stop as soon as a renderer is found and also throw an exception otherwise. This can also be applied to ShapePainter.

Were you thinking of something like this or something different?

[dantleech]

The current design implements a form of this but without signifying if it accepted the responsiblity or not, which is the problem.

The good thing with:

render(Wifdget $widget) {
   if (!$widget instanceof MyWidget) {
      return;
   }
   // widget is MyWidget
]

is that it's:

1. only checks the type once
2. one less method call
3. we have the option of multiople renderers being used for one widget

i'm not sure 3) is valid.

we could return bool from the render method, but I was reserving that maybe for some other info, but maybe it's fine to use it for this 🤷

[KennedyTedesco]

Yes, I don't think that option 3 will ever be a use case. But... who knows. Returning bool there looks reasonable to me. If something changes in the future, we adapt things. Not a big deal.

I'll send a PR with a POC of this.

[dantleech]

Maybe leave it for now, there are other ways to do this and it's not really an issue right now

[KennedyTedesco]

Sure! Yes, right now is more 💅