How to download file from Sanity via HTTP?

Question

I would like to know if there is possibility to download file from Sanity with HTTP request?

I only have reference ID:

{
   file: {
      asset: {
       _ref: "file-fxxxxxxxxxxxxxxxxxxxx-xlsx"
       _type: "reference"
       }    
    }
}

I would like to do this is this scenario:

<a href="https://cdn.sanity.io/assets/clientID/dataset/file-xxxxxxxxxxx-xlsx"> 
Download File 
</a>

Answer 1

You can, indeed With a bit of custom code you can do it just from the _ref, which is the file document's _id

Creating the URL from the _ref/_id of the file

The _ref/_id structure is something like this: file-{ID}-{EXTENSION} (example: file-207fd9951e759130053d37cf0a558ffe84ddd1c9-mp3).

With this, you can generate the downloadable URL, which has the following structure: https://cdn.sanity.io/files/{PROJECT_ID}/{DATASET}/{ID_OF_FILE}.{EXTENSION}. Here's some pseudo Javascript code for the operation:

const getUrlFromId = ref => {
  // Example ref: file-207fd9951e759130053d37cf0a558ffe84ddd1c9-mp3
  // We don't need the first part, unless we're using the same function for files and images
  const [_file, id, extension] = ref.split('-');
  return `https://cdn.sanity.io/files/${PROJECT_ID}/${DATASET}/${id}.${extension}`
}

Querying the URL directly

However, if you can query for the file's document with GROQ that'd be easier:

*[(YOUR FILTER HERE)] {
  file->{ url } // gets the URL from the referenced file
}

You can do the same with images, too.