Documentation

Returns a file upload from the request as a ByteString.

Returns Nothing when the file is not found in the request body.

Example:

Given a form like this:

<form method="POST" action={SubmitMarkdownAction}>
    <input
        type="file"
        name="markdown"
        accept="text/markdown, text/plain"
    >
</form>

The file can be accessed within the action like this:

action SubmitMarkdownAction = do
    let content :: Text =
            fileOrNothing "markdown"
            |> fromMaybe (error "no file given")
            |> (.fileContent)
            |> cs -- content is a LazyByteString, so we use `cs` to convert it to Text

See filesByName if multiple files can be uploaded by the user in a single form submission.

See storeFile to upload the file to S3 or similar cloud storages.

Like fileOrNothing but allows uploading multiple files in the same request

Example:

For uploading multiple files we need to set the multiple attribute on the file input:

<form method="POST" action={SubmitMarkdownAction}>
    <input
        type="file"
        name="markdown"
        accept="text/markdown, text/plain"
        multiple
    >
</form>

When the user selects multiple files, we can access them like this:

action SubmitMarkdownAction = do
    let contents :: [Text] =
            filesByName "markdown"
            |> map (.fileContent)
            |> map cs -- content is a LazyByteString, so we use `cs` to convert it to Text

Use forEach to store multiple files inside the cloud storage:

action SubmitMarkdownAction = do
    let markdownFiles = filesByName "markdown"

    forEach markdownFiles \file -> do
        storeFile file "notes"

        pure ()

Options to be used together with uploadImageWithOptions

Example:

ImageUploadOptions { convertTo = "jpg", imageMagickOptions = "-resize '1024x1024^' -gravity north -extent 1024x1024 -quality 85% -strip" }

Saves an uploaded image file to the uploads directory and writes the relative path to the given record attribute.

Given e.g. an User entity with id = 550e8400-e29b-11d4-a716-446655440000, the file is saved to /uploads/users/550e8400-e29b-11d4-a716-446655440000/picture.jpg.

Before saving, the image is converted using imagemagick. You can supply custom image magick options using the options attribute.

If the upload directory does not exists, it will be created.

Example: Uploading a user profile picture

let profilePictureOptions = ImageUploadOptions
        { convertTo = "jpg"
        , imageMagickOptions = "-resize '1024x1024^' -gravity north -extent 1024x1024 -quality 85% -strip"
        }

user
    |> fill @["firstname", "lastname", "pictureUrl"]
    |> uploadImageWithOptions profilePictureOptions #pictureUrl
    >>= ifValid \case
        Left user -> render EditView { .. }
        Right user -> do
            user <- user |> updateRecord
            redirectTo EditUserAction { .. }

The uploaded image path is now stored in #pictureUrl.

Saves an uploaded image file to the uploads directory.

Given e.g. an User entity with id = 550e8400-e29b-11d4-a716-446655440000, the file is saved to /uploads/users/550e8400-e29b-11d4-a716-446655440000/picture.jpg.

No transformation or validation is applied to the given uploaded file. If you need this, take a look at uploadImageWithOptions.

Example: Uploading a user profile picture

let profilePictureOptions = ImageUploadOptions
        { convertTo = "jpg"
        , imageMagickOptions = "-resize '1024x1024^' -gravity north -extent 1024x1024 -quality 85% -strip"
        }

user
    |> fill @["firstname", "lastname", "pictureUrl"]
    |> uploadImageFile "png" #pictureUrl
    >>= ifValid \case
        Left user -> render EditView { .. }
        Right user -> do
            user <- user |> updateRecord
            redirectTo EditUserAction { .. }

Saves an uploaded png file. No validation or transformation applied. See uploadImageFile for details.

Saves an uploaded svg file. No validation or transformation applied. See uploadImageFile for details.