Cookbook / Files

Upload and keep a file.

Bind an upload to a typed contract field and read it for the length of one request. Keeping it after the request is not covered yet.

Recipe needs validationTarget: 0.16.0Not yet recipe-tested

Contract	Value
Status	Needs validation: Caramel ships no storage adapter, so the recipe stops at the request
Needs	A contract field typed `Caramel::UploadedFile`
You will have	A file bound to a temporary file for the length of the request, within the 64 MiB budget the security reference lists
Proved by	Nothing yet on this page; the rules below are proved by the framework’s own specs

Where the change goes

app/actions/Contract binds the file

spec/requests/Success and rejection checks

These rules run in Caramel 0.16.0 and its specs prove them.

Condition	Outcome
A contract field typed `Caramel::UploadedFile`	binds one multipart file part of that name
The bound file	has `filename`, `content_type`, `path` and `size`; `path` is a temporary file
The request ends	deletes the temporary file; copy it elsewhere to keep it
A route whose contract has no `UploadedFile` field	stores no file; a file part sent to it answers 422 with `Unknown field: cover`
A POST form whose `_method` reaches a route with an `UploadedFile` field	stores the file
More than 128 file parts in one request	answers 413
An `UploadedFile` field with a default	fails compilation
A Corretto request with `files:`, such as `Corretto.upload("spec/fixtures/cover.png", "image/png")`	sends a multipart form

Prove it

Terminal · inside the application

frappe corretto

Passing: A Corretto example accepts a valid file and rejects one that breaks the application’s file rule. This recipe has no such example yet.

Needs validation A parser is only one part of file storage

This recipe does not claim a storage adapter or offer untested persistence code. The complete recipe must establish that path first.