go/src/mime/multipart/writer.go

type Writer …

// NewWriter returns a new multipart [Writer] with a random boundary,
// writing to w.
func NewWriter(w io.Writer) *Writer { … }

// Boundary returns the [Writer]'s boundary.
func (w *Writer) Boundary() string { … }

// SetBoundary overrides the [Writer]'s default randomly-generated
// boundary separator with an explicit value.
//
// SetBoundary must be called before any parts are created, may only
// contain certain ASCII characters, and must be non-empty and
// at most 70 bytes long.
func (w *Writer) SetBoundary(boundary string) error { … }

// FormDataContentType returns the Content-Type for an HTTP
// multipart/form-data with this [Writer]'s Boundary.
func (w *Writer) FormDataContentType() string { … }

func randomBoundary() string { … }

// CreatePart creates a new multipart section with the provided
// header. The body of the part should be written to the returned
// [Writer]. After calling CreatePart, any previous part may no longer
// be written to.
func (w *Writer) CreatePart(header textproto.MIMEHeader) (io.Writer, error) { … }

var quoteEscaper …

func escapeQuotes(s string) string { … }

// CreateFormFile is a convenience wrapper around [Writer.CreatePart]. It creates
// a new form-data header with the provided field name and file name.
func (w *Writer) CreateFormFile(fieldname, filename string) (io.Writer, error) { … }

// CreateFormField calls [Writer.CreatePart] with a header using the
// given field name.
func (w *Writer) CreateFormField(fieldname string) (io.Writer, error) { … }

// WriteField calls [Writer.CreateFormField] and then writes the given value.
func (w *Writer) WriteField(fieldname, value string) error { … }

// Close finishes the multipart message and writes the trailing
// boundary end line to the output.
func (w *Writer) Close() error { … }

type part …

func (p *part) close() error { … }

func (p *part) Write(d []byte) (n int, err error) { … }