vapor-docs/3.0/docs/http/body.md

Body

Body contains the bytes transmitted for a Request or Response. It's contents are related to the Content-Type header.

Body is a binary blob but can contain text like HTML, JSON or another text-based format. It can also contain binary data such as images, ZIP and other files.

Creating a Body

Empty bodies can be created using the empty initializer Body(). Alternatively you can provide Data or DispatchData as the content of the body.

BodyRepresentable

When adding a new struct/class that can be serialized to a Body as part of a Request or Response you can consider implementing the BodyRepresentable protocol. Below is how String is implemented.

/// String can be represented as an HTTP body.
extension String: BodyRepresentable {
    /// See BodyRepresentable.makeBody()
    public func makeBody() throws -> Body {
        guard let data = self.data(using: .utf8) else {
            throw Error(identifier: "string-body-conversion", reason: "Converting a String to an HTTP Body failed.")
        }

        return Body(data)
    }
}

The protocol requires the implementation of the makeBody function that creates a new Body.

Although often unnecessary it is possible to throw an error here if the creation of the body failed.