Add http.Adapt function (#92) In the new package `http`, an `Adapt` function converts a `Handler` into a `http.HandlerFunc` from the `http` stdlib package.
1 file changed, 42 insertions(+), 0 deletions(-)
changed files
A http/handler.go
@@ -0,0 +1,42 @@ +// Package http provides adapters to render gomponents in http handlers. +package http + +import ( + "net/http" + + g "github.com/maragudk/gomponents" +) + +// Handler is like http.Handler but returns a Node and an error. +// See Adapt for how errors are translated to HTTP responses. +type Handler = func(http.ResponseWriter, *http.Request) (g.Node, error) + +type errorWithStatusCode interface { + StatusCode() int +} + +// Adapt a Handler to a http.Handlerfunc. +// The returned Node is rendered to the ResponseWriter, in both normal and error cases. +// If the Handler returns an error, and it implements a "StatusCode() int" method, that HTTP status code is sent +// in the response header. Otherwise, the status code http.StatusInternalServerError (500) is used. +func Adapt(h Handler) http.HandlerFunc { + return func(w http.ResponseWriter, r *http.Request) { + n, err := h(w, r) + if err != nil { + switch v := err.(type) { + case errorWithStatusCode: + w.WriteHeader(v.StatusCode()) + default: + w.WriteHeader(http.StatusInternalServerError) + } + } + + if n == nil { + return + } + + if err := n.Render(w); err != nil { + http.Error(w, "error rendering node: "+err.Error(), http.StatusInternalServerError) + } + } +}