# Block Viewer
`BlockViewer` is the page-root component used by the BaseUI block gallery detail pages (`examples/blocks/*.html`). It reads a title/description from `document.body.dataset`, renders a sample block's markup from a `[b-block-code-template]` script tag into a live preview panel, and offers a preview/code toggle with desktop/tablet/mobile viewport switching and a "copy code" action.
## CDN install requirements
Load the pinned BaseUI CSS and JavaScript files, plus the block-viewer adapter bundle (it is not part of `baseui.min.js`, since it pulls in the full component export surface only when a block sample needs it — but it's self-contained, no import map required):
```html
```
## Pure Owl component
```js
import { BlockViewer } from "@base/component";
```
```base-ui
```
## Static component
```html
```
`BaseUI.mountAll()` (called automatically on `DOMContentLoaded`) mounts the `b-ui="block-viewer"` element as a full Owl app, using the block's own inline template as its live preview and its serialized text as the "Code" panel.
## Options and attributes
- `data-block-title` / `data-block-description` (on ``) — the header title/description shown above the preview.
- `[b-block-code-template]` — a `