Shadcn/ui Combobox - v0 by Vercel

I’m looking at this shadcn/ui documentation: https://ui.shadcn.com/docs/components/combobox. Help me understand how to use it. Be ready to explain concepts, give examples, or help debug based on it.

I'll fetch the shadcn/ui combobox documentation to help you understand how to use it effectively.

I now have the complete shadcn/ui combobox documentation. Let me break down how the Combobox component works and help you understand its key concepts:

What is the Combobox?

The Combobox is an autocomplete input with a searchable dropdown list. It combines a text input with a filterable list of options, making it perfect for scenarios where users need to select from many options or want to type to filter results.

Key Architecture

The Combobox is built using composition of two main components:

Popover - Handles the dropdown positioning and visibility
Command - Provides the search/filter functionality and list rendering

Core Concepts

1. State Management

const [open, setOpen] = React.useState(false)  // Controls dropdown visibility
const [value, setValue] = React.useState("")   // Stores selected value

2. Data Structure

Options are typically structured as objects with value and label:

const frameworks = [
  { value: "next.js", label: "Next.js" },
  { value: "sveltekit", label: "SvelteKit" },
  // ...
]

3. Key Components

PopoverTrigger - The button that opens the dropdown
CommandInput - The search input inside the dropdown
CommandEmpty - Shows when no results match the search
CommandItem - Individual selectable options

Common Use Cases

Framework/Technology Selector - Choose from many options with search
Status Picker - Select project status with visual indicators
Form Fields - Searchable dropdowns in forms with validation
Responsive Design - Desktop popover, mobile drawer

Key Features

Search/Filter - Type to filter options instantly
Keyboard Navigation - Arrow keys, Enter, Escape support
Accessibility - ARIA labels and proper focus management
Customizable - Easy to style and extend
Form Integration - Works seamlessly with React Hook Form

When to Use vs Alternatives

Use Combobox when: You have many options (10+) or want search functionality
Use Select when: You have fewer options and don't need search
Use Autocomplete when: You want free-form input with suggestions

Would you like me to create a working example, explain any specific part in more detail, or help you implement it for a particular use case?

does combobox support scrolling of options?

Yes, the shadcn/ui Combobox does support scrolling of options!

Looking at the documentation, I can see that the Combobox uses the CommandList component, which automatically handles scrolling when there are many options. Here's how it works:

Scrolling Implementation

The key component that enables scrolling is <CommandList>:

<Command>
  <CommandInput placeholder="Search framework..." />
  <CommandEmpty>No framework found.</CommandEmpty>
  <CommandList> {/* This handles scrolling */}
    <CommandGroup>
      {frameworks.map((framework) => (
        <CommandItem key={framework.value}>
          {framework.label}
        </CommandItem>
      ))}
    </CommandGroup>
  </CommandList>
</Command>

How Scrolling Works

Automatic Height Management - The CommandList automatically constrains the height of the dropdown
Native Scrolling - When options exceed the available space, native scrolling kicks in
Keyboard Navigation - You can still use arrow keys to navigate through all options, even when scrolling
Search + Scroll - The search functionality works seamlessly with scrolling

Customizing Scroll Behavior

You can customize the scrolling area by:

Setting max height on the PopoverContent
Using the ScrollArea component for more control
Styling the CommandList with custom CSS classes

The Combobox is designed to handle large datasets gracefully - you can have hundreds of options and it will scroll smoothly while maintaining search and keyboard navigation functionality.

can you show me an example with let's say 30 options?

app

page.tsx