Task - Manage the format requested by the client

Created by: benoitdm-oslandia

In GitLab by @nrevelant on Oct 13, 2022, 16:43

Currently, pgfeatureserve seems to let the client choose the responses format on GET requests. :

• through route suffix, like file extension (net.go) :

func RequestedFormat(r *http.Request) string {
	// first check explicit path
	path := r.URL.EscapedPath()
	if strings.HasSuffix(path, ".html") {
		return FormatHTML
	}
	if strings.HasSuffix(path, ".json") {
		return FormatJSON
	}
	if strings.HasSuffix(path, ".txt") {
		return FormatText
	}
	if strings.HasSuffix(path, ".svg") {
		return FormatSVG
	}

• through the "Accept" header

	// Use Accept header if present
	hdrAccept := r.Header.Get("Accept")
	//fmt.Println("Accept:" + hdrAccept)
	if strings.Contains(hdrAccept, ContentTypeSchemaJSON) {
		return FormatSchemaJSON
	}
	if strings.Contains(hdrAccept, ContentTypeHTML) {
		return FormatHTML
	}
	return FormatJSON

However this parameter seems to have a limited support with mostly JSON formatted response ( handleItem() function inside handler.go ) :

		switch format {
		case api.FormatJSON:
			return writeItemJSON(ctx, w, name, fid, param, urlBase, crs)
		case api.FormatHTML:
			return writeItemHTML(w, tbl, name, fid, query, urlBase)
		default:
			return nil
		}

The TestWeakEtagFromDifferentRepresentationsDb test for example will cover this use case.

NB: In the case of an unsupported format, the return code should be : 406 Not Acceptable