// WriteEvent does the actual work of formatting an SSE compliant message
// sending it over the provided ResponseWriter and flushing.
func WriteEvent(ctx context.Context, w http.ResponseWriter, e Event) {
if e.Error != nil {
fmt.Fprint(w, "event: err\n")
fmt.Fprintf(w, "data: %s\n\n", e.Error.Error())
w.(http.Flusher).Flush()
log.Error(ctx, e.Error)
return
}
// TODO: add tests to ensure retry get's properly rendered
if e.Retry != 0 {
fmt.Fprintf(w, "retry: %d\n", e.Retry)
}
if e.ID != "" {
fmt.Fprintf(w, "id: %s\n", e.ID)
}
if e.Event != "" {
fmt.Fprintf(w, "event: %s\n", e.Event)
}
fmt.Fprintf(w, "data: %s\n\n", getJSON(e.Data))
w.(http.Flusher).Flush()
}
func render(ctx context.Context, w http.ResponseWriter, p P) {
Inflate(ctx, &p)
w.Header().Set("Content-Type", "application/problem+json")
js, err := json.MarshalIndent(p, "", " ")
if err != nil {
log.Error(ctx, err)
http.Error(w, "error rendering problem", http.StatusInternalServerError)
return
}
w.WriteHeader(p.Status)
w.Write(js)
}
// Render writes a http response to `w`, compliant with the "Problem
// Details for HTTP APIs" RFC:
// https://tools.ietf.org/html/draft-ietf-appsawg-http-problem-00
//
// `p` is the problem, which may be either a concrete P struct, an implementor
// of the `HasProblem` interface, or an error. Any other value for `p` will
// panic.
func Render(ctx context.Context, w http.ResponseWriter, p interface{}) {
switch p := p.(type) {
case P:
render(ctx, w, p)
case *P:
render(ctx, w, *p)
case error:
pp, ok := errToProblemMap[p]
if !ok {
log.Error(ctx, p)
pp = ServerError
}
render(ctx, w, pp)
default:
panic(fmt.Sprintf("Invalid problem: %v+", p))
}
}