The place to store files would be a problem when you intend to write a web application which allows file-uploading. These days, AWS S3 is a common place to store/serve files, however, it's not easy to manage like RDBMS.
Mito-attachment provides a Mito mixin class for managing files outside of RDBMS. It stores files before mito:save-dao
and deletes them before mito:delete-dao
.
Besides, the backend storage can be replaced easily. This makes it easy that using cloud storage services for production environment and using local filesystem for development environment.
(defvar *appenv* (uiop:getenv "APP_ENV"))
;; Setup storage class
(setf *storage*
(if (string= *appenv* "production")
;; Store files in AWS S3 for production environment
(make-instance 's3-storage
:bucket "mito-attachment-example"
:endpoint "s3-ap-northeast-1.amazonaws.com"
:access-key (uiop:getenv "AWS_ACCESS_KEY")
:secret-key (uiop:getenv "AWS_SECRET_KEY"))
;; Store files in local filesystem for development environment
(make-instance 'disk-storage
:bucket "mito-attachment-example"
:directory #P"/tmp/attachment/")))
;; Attachment class for saving metadata into RDBMS
(defclass image (attachment) ()
(:metaclass mito:dao-table-class))
;; :content can be specified as a pathname or a stream.
(mito:create-dao 'image :content #P"uploaded-file.png")
;; Override the file content-type
(mito:create-dao 'image :content #P"uploaded-file.png" :content-type "image/png")
;; Use an original file-key
(mito:create-dao 'image :content #P"uploaded-file.png" :file-key "image.png")
(let ((file (mito:find-dao 'image :id 1)))
(file-url file))
;-> ;; SELECT * FROM "image" WHERE ("id" = ?) LIMIT 1 (1) [1 row] | MITO.DB:RETRIEVE-BY-SQL
;=> "/mito-attachment-example/3616D80112884799B272DC962F4BBF97.jpg"
Additionally, file-signed-url
can also be used for getting a signed URL (ex. Amazon S3 Presigned URL).
See example.lisp for getting the full example. It's a Lack web application which allows users to upload image files.
(ql:quickload :mito-attachment)
- Eitaro Fukamachi (e.arrows@gmail.com)
Copyright (c) 2016 Eitaro Fukamachi (e.arrows@gmail.com)
Licensed under the LLGPL License.