datasette-media 0.2

Datasette plugin for serving media based on a SQL query

datasette-media

Datasette plugin for serving media based on a SQL query.

Use this when you have a database table containing references to files that you would like to be able to serve to your users.

Installation

Install this plugin in the same environment as Datasette.

$ pip install datasette-media

HEIC image support

Modern iPhones save their photos using the HEIC image format. Processing these images requires an additional dependency, pyheif. You can include this dependency by running:

$ pip install datasette-media[heif]

Usage

You can use this plugin to configure Datasette to serve static media based on SQL queries to an underlying database table.

Media will be served from URLs that start with /-/media/. The full URL to each media asset will look like this:

/-/media/type-of-media/media-key

type-of-media will correspond to a configured SQL query, and might be something like photo. media-key will be an identifier that is used as part of the underlying SQL query to find which file should be served.

Serving static files from disk

The following metadata.json configuration will cause this plugin to serve files from disk, based on queries to a database table called apple_photos:

{
    "plugins": {
        "datasette-media": {
            "photo": {
                "sql": "select filepath from apple_photos where uuid=:key"
            }
        }
    }
}

A request to /-/media/photo/CF972D33-5324-44F2-8DAE-22CB3182CD31 will execute the following SQL query:

select filepath from apple_photos where uuid=:key

The value from the URL - in this case CF972D33-5324-44F2-8DAE-22CB3182CD31 - will be passed as the :key parameter to the query.

The query returns a filepath value that has been read from the table. The plugin will then read that file from disk and serve it in response to the request.

SQL queries default to running against the first connected database. You can specify a different database to execute the query against using "database": "name_of_db". To execute against photos.db, use this:

{
    "plugins": {
        "datasette-media": {
            "photo": {
                "sql": "select filepath from apple_photos where uuid=:key",
                "database": "photos"
            }
        }
    }
}

See photos-to-sqlite for an example of an application that can benefit from this plugin.

Resizing or reformatting images

Your SQL query can specify that an image should be resized and/or converted to another format by returning additional columns. All three are optional.

• resize_width - the width to resize the image to
• resize_width - the height to resize the image to
• output_format - the output format to use (e.g. jpeg or png) - any output format supported by Pillow is allowed here

If you specify one but not the other of resize_width or resize_height the unspecified one will be calculated automatically to maintain the aspect ratio of the image.

Here's an example configuration that will resize all images to be JPEGs that are 200 pixels in height:

{
    "plugins": {
        "datasette-media": {
            "photo": {
                "sql": "select filepath, 200 as resize_height, 'jpeg' as output_format from apple_photos where uuid=:key",
                "database": "photos"
            }
        }
    }
}