Implementing FieldPicker formatting setting

Hello MartinRKrupa, while I had no luck figuring out how to do it (if it's even possible), I did find a workaround. VisualEnumerationInstanceKinds allows users to add measures as values for settings in PowerBI Custom Visuals via Conditional Formatting.

It's not perfect, but it might be possible for you to achieve something similar.

    public fontColor: formattingSettings.ColorPicker = new formattingSettings.ColorPicker({
        name: 'fontColor',
        displayName: 'Text color',
        instanceKind: VisualEnumerationInstanceKinds.ConstantOrRule,
        value: {
            value: ''
        }
    });

The above example is a simple color picker example. Using the VisualEnumerationInstanceKinds.ConstantOrRule, users get the f(x) icon next to the setting and can set it to a measure (although in this case the output should be a hex color code). With this, users can easily define their own dynamic values for color style, e.g. for a "dark mode".

Most formattingSettings I have seen allow the instanceKind property.