Multipart Requests

Multipart request bodies (multipart/form-data) can be constructed declaratively using RequestBodyMultipart with composable parts.

Form Fields

Use FormField to add text fields to a multipart request.

httpc := httpr.NewClient()

resp, err := httpc.Post(
    context.Background(),
    "https://api.example.com/submit",
    httpr.RequestBodyMultipart(
        httpr.FormField("username", "moe"),
        httpr.FormField("description", "a cool thing"),
    ),
)

File Uploads

Use FormFile to attach a file from an io.Reader, or FormFileBytes to attach a file from a byte slice.

From an io.Reader

httpc := httpr.NewClient()

file, err := os.Open("document.pdf")
if err != nil {
    // Handle error
}
defer file.Close()

resp, err := httpc.Post(
    context.Background(),
    "https://api.example.com/upload",
    httpr.RequestBodyMultipart(
        httpr.FormFile("document", "document.pdf", file),
    ),
)

From Bytes

httpc := httpr.NewClient()

imageData, err := os.ReadFile("photo.png")
if err != nil {
    // Handle error
}

resp, err := httpc.Post(
    context.Background(),
    "https://api.example.com/upload",
    httpr.RequestBodyMultipart(
        httpr.FormFileBytes("avatar", "photo.png", imageData),
    ),
)

Mixed Fields and Files

Fields and files can be freely combined in a single request.

httpc := httpr.NewClient()

file, err := os.Open("photo.jpg")
if err != nil {
    // Handle error
}
defer file.Close()

resp, err := httpc.Post(
    context.Background(),
    "https://api.example.com/profile",
    httpr.RequestBodyMultipart(
        httpr.FormField("username", "moe"),
        httpr.FormField("role", "admin"),
        httpr.FormFile("avatar", "photo.jpg", file),
    ),
)

Custom Multipart Writer

For advanced use cases that need full control over the multipart.Writer, use RequestBodyMultipartFunc.

httpc := httpr.NewClient()

resp, err := httpc.Post(
    context.Background(),
    "https://api.example.com/custom",
    httpr.RequestBodyMultipartFunc(func(w *multipart.Writer) error {
        if err := w.WriteField("metadata", `{"type":"report"}`); err != nil {
            return err
        }

        part, err := w.CreateFormFile("file", "report.csv")
        if err != nil {
            return err
        }

        _, err = part.Write(csvBytes)
        return err
    }),
)