Add disabled property to dropdown-select-item

[marcuskrahl]

Describe the feature request
The Dropdown Select component currently lacks the ability to disable individual Dropdown Select Items.
It is supposed to replace native <select> elements and it is possible for <option> elements inside a <select> or <scale-dropdown> element to be disabled.

Describe the use case
It is sometimes necessary to show options to a user which are currently unavailable, but might be available under different circumstances. When showing these disabled options we can also provide a reason for the user why these options are unavailable.

Describe alternatives you've considered

• using <scale-dropdown>, but it is deprecated
• using checkboxes, but sometimes a dropdown is the most appropriate control

Additional context
We might also want to consider other features of native selects, lke <optgroup>, etc.

[dadadcko]

Hello! I'd like to help. May I take and work on this feature?

Edit: Mention one of code owners to get attention
@felix-ico

[felix-ico]

Hi @dadadcko, sorry for the delay, I was out of office. Yes of course you may open a PR for this feature request, and let me know if you have any questions!

[dadadcko]

Hey @felix-ico, I have dig through source-code and see that dropdown-select-item only acts as placeholder for data but all styles and logic is actually implemented in dropdown-select.
Regarding the styles, should be disabled implemented the same way? E.g. disabled text color should be set from (by) dropdown-select, or directly in dropdown-select-item ?

The above also makes problem for implementing disabled reason message. Currently, when any option is selected, the whole element is rendered. This makes problem when we only want to display reason message in list-pad box, not when the element is already actually selected. Should displaying the reason message be part of (and responsibility of) parent - dropdown-select ?

I have already experimented with both solutions, but I want to get clarification from you before I commit the final implementation :)