How to access image metadata in Sanity custom input component?

When you're working with a custom input component and only seeing _ref and _type in your image asset field, you'll need to query the actual asset document to get the metadata. The image field only stores a reference to the asset, not the metadata itself.

Here's how you can access the image metadata in your custom input component:

First, make sure you've configured your image field schema to include the metadata you need. In your schema definition, add the metadata options:

{
  name: 'myImage',
  type: 'image',
  options: {
    metadata: ['exif', 'location', 'palette'] // Add the metadata types you need
  }
}

Note that dimensions, hasAlpha, and isOpaque are always included automatically, while blurhash, lqip, and palette are included by default. You need to explicitly add exif and location if you want those.

In your custom input component, you'll need to use the Sanity client to fetch the full asset document:

import { useClient } from 'sanity'
import { useEffect, useState } from 'react'

export function MyCustomImageInput(props) {
  const client = useClient({apiVersion: '2023-01-01'})
  const [metadata, setMetadata] = useState(null)
  
  useEffect(() => {
    const assetRef = props.value?.asset?._ref
    
    if (assetRef) {
      // Query the asset document to get metadata
      client.fetch(`*[_id == $assetId][0].metadata`, { assetId: assetRef })
        .then(data => setMetadata(data))
    }
  }, [props.value?.asset?._ref])
  
  // Now you can access metadata.dimensions, metadata.palette, etc.
  return (
    <div>
      {props.renderDefault(props)}
      {metadata && (
        <div>
          <p>Dimensions: {metadata.dimensions?.width} x {metadata.dimensions?.height}</p>
          <p>Palette: {JSON.stringify(metadata.palette)}</p>
        </div>
      )}
    </div>
  )
}

There's also a helpful guide on creating a custom input component for metadata that shows how to display and even edit metadata directly at the document level.

Important note: Metadata is processed asynchronously after upload, so it might not be immediately available. Your queries might return empty results right after uploading an image until the processing completes.

The metadata you can access includes:

• dimensions (width/height) - always included
• palette (color information) - included by default
• lqip (low quality image placeholder) - included by default
• blurhash - included by default
• exif (camera/photo data) - must be explicitly enabled
• location (GPS coordinates) - must be explicitly enabled