# Ref Documentation Learn about the $bindable ref prop. This is a documentation section that potentially contains examples, demos, and other useful information related to a specific part of Bits UI. When helping users with this documentation, you can ignore the classnames applied to the demos unless they are relevant to the user's issue. Copy Page The `ref` prop provides direct access to the underlying HTML elements in Bits UI components, enabling you to manipulate the DOM when necessary. ## Basic Usage Every Bits UI component that renders an HTML element exposes a `ref` prop that you can bind to access the rendered element. This is particularly useful for programmatically manipulating the element, such as focusing inputs or measuring dimensions. ```svelte Trigger content ``` ## With Child Snippet Bits UI uses element IDs to track references to underlying elements. This approach ensures that the `ref` prop works correctly even when using the [child snippet](/docs/child-snippet). ### Simple Delegation Example The `ref` binding will automatically work with delegated child elements/components. ```svelte {#snippet child({ props })} {/snippet} ``` ### Using Custom IDs When you need to use a custom `id` on the element, pass it to the parent component first so it can be correctly registered with the `ref` binding: ```svelte {#snippet child({ props })} {/snippet} ``` ### Common Pitfalls Avoid setting the `id` directly on the child component/element, as this breaks the connection between the `ref` binding and the element: ```svelte {#snippet child({ props })} {/snippet} ``` In this example, the `Accordion.Trigger` component can't track the element because it doesn't know the custom ID. ## Why Possibly `null`? The `ref` value may be `null` until the component mounts in the DOM. This behavior is consistent with native DOM methods like `getElementById` which can return `null`. ## Creating Your Own `ref` Props To implement the same ref pattern in your custom components, Bits UI provides a [WithElementRef](/docs/type-helpers/with-element-ref) type helper. This enables you to create type-safe components that follow the same pattern. ```svelte ``` [Previous Child Snippet](/docs/child-snippet) [Next Transitions](/docs/transitions)

ref-prop-binding