[linux] Add support for WebKit2GTK 2.36+ features (#2151)

v2/internal/frontend/desktop/linux/frontend.go

@@ -126,15 +126,17 @@ func (f *Frontend) WindowClose() {
 
 func init() {
 	runtime.LockOSThread()
-}
-
-func NewFrontend(ctx context.Context, appoptions *options.App, myLogger *logger.Logger, appBindings *binding.Bindings, dispatcher frontend.Dispatcher) *Frontend {
 
 	// Set GDK_BACKEND=x11 if currently unset and XDG_SESSION_TYPE is unset, unspecified or x11 to prevent warnings
 	if os.Getenv("GDK_BACKEND") == "" && (os.Getenv("XDG_SESSION_TYPE") == "" || os.Getenv("XDG_SESSION_TYPE") == "unspecified" || os.Getenv("XDG_SESSION_TYPE") == "x11") {
 		_ = os.Setenv("GDK_BACKEND", "x11")
 	}
 
+	C.gtk_init(nil, nil)
+}
+
+func NewFrontend(ctx context.Context, appoptions *options.App, myLogger *logger.Logger, appBindings *binding.Bindings, dispatcher frontend.Dispatcher) *Frontend {
+
 	result := &Frontend{
 		frontendOptions: appoptions,
 		logger:          myLogger,
@@ -171,8 +173,6 @@ func NewFrontend(ctx context.Context, appoptions *options.App, myLogger *logger.
 
 	go result.startMessageProcessor()
 
-	C.gtk_init(nil, nil)
-
 	var _debug = ctx.Value("debug")
 	if _debug != nil {
 		result.debug = _debug.(bool)
@@ -480,8 +480,6 @@ func (f *Frontend) processRequest(request unsafe.Pointer) {
 	uri := C.webkit_uri_scheme_request_get_uri(req)
 	goURI := C.GoString(uri)
 
-	// WebKitGTK stable < 2.36 API does not support request method, request headers and request.
-	// Apart from request bodies, this is only available beginning with 2.36: https://webkitgtk.org/reference/webkit2gtk/stable/WebKitURISchemeResponse.html
 	rw := &webKitResponseWriter{req: req}
 	defer rw.Close()
 
@@ -489,20 +487,22 @@ func (f *Frontend) processRequest(request unsafe.Pointer) {
 		goURI,
 		rw,
 		func() (*http.Request, error) {
-			req, err := http.NewRequest(http.MethodGet, goURI, nil)
+			method := webkit_uri_scheme_request_get_http_method(req)
+			r, err := http.NewRequest(method, goURI, nil)
 			if err != nil {
 				return nil, err
 			}
+			r.Header = webkit_uri_scheme_request_get_http_headers(req)
 
-			if req.URL.Host != f.startURL.Host {
-				if req.Body != nil {
-					req.Body.Close()
+			if r.URL.Host != f.startURL.Host {
+				if r.Body != nil {
+					r.Body.Close()
 				}
 
-				return nil, fmt.Errorf("Expected host '%s' in request, but was '%s'", f.startURL.Host, req.URL.Host)
+				return nil, fmt.Errorf("Expected host '%s' in request, but was '%s'", f.startURL.Host, r.URL.Host)
 			}
 
-			return req, nil
+			return r, nil
 		})
 
 }

v2/internal/frontend/desktop/linux/webkit2.go

@@ -0,0 +1,29 @@
+//go:build linux
+
+package linux
+
+/*
+#cgo linux pkg-config: webkit2gtk-4.0
+#include "webkit2/webkit2.h"
+*/
+import "C"
+import (
+	"fmt"
+
+	"github.com/wailsapp/wails/v2/pkg/options"
+	"github.com/wailsapp/wails/v2/pkg/options/linux"
+)
+
+func validateWebKit2Version(options *options.App) {
+	if C.webkit_get_major_version() == 2 && C.webkit_get_minor_version() >= webkit2MinMinorVersion {
+		return
+	}
+
+	msg := linux.DefaultMessages()
+	if options.Linux != nil && options.Linux.Messages != nil {
+		msg = options.Linux.Messages
+	}
+
+	v := fmt.Sprintf("2.%d.0", webkit2MinMinorVersion)
+	showModalDialogAndExit("WebKit2GTK", fmt.Sprintf(msg.WebKit2GTKMinRequired, v))
+}

v2/internal/frontend/desktop/linux/webkit2_36.go

@@ -0,0 +1,73 @@
+//go:build linux && webkit2_36
+
+package linux
+
+/*
+#cgo linux pkg-config: gtk+-3.0 webkit2gtk-4.0 libsoup-2.4
+
+#include "gtk/gtk.h"
+#include "webkit2/webkit2.h"
+#include "libsoup/soup.h"
+*/
+import "C"
+
+import (
+	"net/http"
+	"strings"
+	"unsafe"
+
+	"github.com/wailsapp/wails/v2/internal/frontend/assetserver"
+)
+
+const webkit2MinMinorVersion = 36
+
+func webkit_uri_scheme_request_get_http_method(req *C.WebKitURISchemeRequest) string {
+	method := C.GoString(C.webkit_uri_scheme_request_get_http_method(req))
+	return strings.ToUpper(method)
+}
+
+func webkit_uri_scheme_request_get_http_headers(req *C.WebKitURISchemeRequest) http.Header {
+	hdrs := C.webkit_uri_scheme_request_get_http_headers(req)
+
+	var iter C.SoupMessageHeadersIter
+	C.soup_message_headers_iter_init(&iter, hdrs)
+
+	var name *C.char
+	var value *C.char
+
+	h := http.Header{}
+	for C.soup_message_headers_iter_next(&iter, &name, &value) != 0 {
+		h.Add(C.GoString(name), C.GoString(value))
+	}
+
+	return h
+}
+
+func webkit_uri_scheme_request_finish(req *C.WebKitURISchemeRequest, code int, header http.Header, stream *C.GInputStream, streamLength int64) error {
+	resp := C.webkit_uri_scheme_response_new(stream, C.gint64(streamLength))
+	defer C.g_object_unref(C.gpointer(resp))
+
+	cReason := C.CString(http.StatusText(code))
+	C.webkit_uri_scheme_response_set_status(resp, C.guint(code), cReason)
+	C.free(unsafe.Pointer(cReason))
+
+	cMimeType := C.CString(header.Get(assetserver.HeaderContentType))
+	C.webkit_uri_scheme_response_set_content_type(resp, cMimeType)
+	C.free(unsafe.Pointer(cMimeType))
+
+	hdrs := C.soup_message_headers_new(C.SOUP_MESSAGE_HEADERS_RESPONSE)
+	for name, values := range header {
+		cName := C.CString(name)
+		for _, value := range values {
+			cValue := C.CString(value)
+			C.soup_message_headers_append(hdrs, cName, cValue)
+			C.free(unsafe.Pointer(cValue))
+		}
+		C.free(unsafe.Pointer(cName))
+	}
+
+	C.webkit_uri_scheme_response_set_http_headers(resp, hdrs)
+
+	C.webkit_uri_scheme_request_finish_with_response(req, resp)
+	return nil
+}

v2/internal/frontend/desktop/linux/webkit2_legacy.go

@@ -0,0 +1,40 @@
+//go:build linux && !webkit2_36
+
+package linux
+
+/*
+#cgo linux pkg-config: gtk+-3.0 webkit2gtk-4.0
+
+#include "gtk/gtk.h"
+#include "webkit2/webkit2.h"
+*/
+import "C"
+
+import (
+	"fmt"
+	"net/http"
+	"unsafe"
+
+	"github.com/wailsapp/wails/v2/internal/frontend/assetserver"
+)
+
+const webkit2MinMinorVersion = 0
+
+func webkit_uri_scheme_request_get_http_method(_ *C.WebKitURISchemeRequest) string {
+	return http.MethodGet
+}
+
+func webkit_uri_scheme_request_get_http_headers(_ *C.WebKitURISchemeRequest) http.Header {
+	return http.Header{}
+}
+
+func webkit_uri_scheme_request_finish(req *C.WebKitURISchemeRequest, code int, header http.Header, stream *C.GInputStream, streamLength int64) error {
+	if code != http.StatusOK {
+		return fmt.Errorf("StatusCodes not supported: %d - %s", code, http.StatusText(code))
+	}
+
+	cMimeType := C.CString(header.Get(assetserver.HeaderContentType))
+	C.webkit_uri_scheme_request_finish(req, stream, C.gint64(streamLength), cMimeType)
+	C.free(unsafe.Pointer(cMimeType))
+	return nil
+}

v2/internal/frontend/desktop/linux/webkit2_responsewriter.go

@@ -55,27 +55,6 @@ func (rw *webKitResponseWriter) WriteHeader(code int) {
 	}
 	rw.wroteHeader = true
 
-	if code != http.StatusOK {
-		// WebKitGTK stable < 2.36 API does not support response headers and response statuscodes
-		rw.w = &nopCloser{io.Discard}
-		rw.finishWithError(http.StatusText(code), code)
-		return
-	}
-
-	// We can't use os.Pipe here, because that returns files with a finalizer for closing the FD. But the control over the
-	// read FD is given to the InputStream and will be closed there.
-	// Furthermore we especially don't want to have the FD_CLOEXEC
-	rFD, w, err := pipe()
-	if err != nil {
-		rw.wErr = fmt.Errorf("Unable opening pipe: %s", err)
-		rw.finishWithError(rw.wErr.Error(), http.StatusInternalServerError)
-		return
-	}
-	rw.w = w
-
-	cMimeType := C.CString(rw.Header().Get(assetserver.HeaderContentType))
-	defer C.free(unsafe.Pointer(cMimeType))
-
 	contentLength := int64(-1)
 	if sLen := rw.Header().Get(assetserver.HeaderContentLength); sLen != "" {
 		if pLen, _ := strconv.ParseInt(sLen, 10, 64); pLen > 0 {
@@ -83,9 +62,23 @@ func (rw *webKitResponseWriter) WriteHeader(code int) {
 		}
 	}
 
+	// We can't use os.Pipe here, because that returns files with a finalizer for closing the FD. But the control over the
+	// read FD is given to the InputStream and will be closed there.
+	// Furthermore we especially don't want to have the FD_CLOEXEC
+	rFD, w, err := pipe()
+	if err != nil {
+		rw.finishWithError(http.StatusInternalServerError, fmt.Errorf("unable to open pipe: %s", err))
+		return
+	}
+	rw.w = w
+
 	stream := C.g_unix_input_stream_new(C.int(rFD), gtkBool(true))
-	C.webkit_uri_scheme_request_finish(rw.req, stream, C.gint64(contentLength), cMimeType)
-	C.g_object_unref(C.gpointer(stream))
+	defer C.g_object_unref(C.gpointer(stream))
+
+	if err := webkit_uri_scheme_request_finish(rw.req, code, rw.Header(), stream, contentLength); err != nil {
+		rw.finishWithError(http.StatusInternalServerError, fmt.Errorf("unable to finish request: %s", err))
+		return
+	}
 }
 
 func (rw *webKitResponseWriter) Close() {
@@ -94,8 +87,14 @@ func (rw *webKitResponseWriter) Close() {
 	}
 }
 
-func (rw *webKitResponseWriter) finishWithError(message string, code int) {
-	msg := C.CString(http.StatusText(code))
+func (rw *webKitResponseWriter) finishWithError(code int, err error) {
+	if rw.w != nil {
+		rw.w.Close()
+		rw.w = &nopCloser{io.Discard}
+	}
+	rw.wErr = err
+
+	msg := C.CString(err.Error())
 	gerr := C.g_error_new_literal(C.g_quark_from_string(msg), C.int(code), msg)
 	C.webkit_uri_scheme_request_finish_error(rw.req, gerr)
 	C.g_error_free(gerr)

v2/internal/frontend/desktop/linux/window.go

@@ -642,6 +642,7 @@ static void SetWindowTransparency(GtkWidget *widget)
 */
 import "C"
 import (
+	"log"
 	"strings"
 	"sync"
 	"unsafe"
@@ -679,6 +680,7 @@ func bool2Cint(value bool) C.int {
 }
 
 func NewWindow(appoptions *options.App, debug bool) *Window {
+	validateWebKit2Version(appoptions)
 
 	result := &Window{
 		appoptions: appoptions,
@@ -1034,3 +1036,19 @@ func (w *Window) ToggleMaximise() {
 		w.Maximise()
 	}
 }
+
+// showModalDialogAndExit shows a modal dialog and exits the app.
+func showModalDialogAndExit(title, message string) {
+	go func() {
+		data := C.MessageDialogOptions{
+			title:       C.CString(title),
+			message:     C.CString(message),
+			messageType: C.int(1),
+		}
+
+		C.messageDialog(unsafe.Pointer(&data))
+	}()
+
+	<-messageDialogResult
+	log.Fatal(message)
+}

v2/pkg/options/linux/linux.go

@@ -4,4 +4,17 @@ package linux
 type Options struct {
 	Icon                []byte
 	WindowIsTranslucent bool
+
+	// User messages that can be customised
+	Messages *Messages
+}
+
+type Messages struct {
+	WebKit2GTKMinRequired string
+}
+
+func DefaultMessages() *Messages {
+	return &Messages{
+		WebKit2GTKMinRequired: "This application requires at least WebKit2GTK %s to be installed.",
+	}
 }

website/docs/reference/options.mdx

@@ -250,23 +250,23 @@ dynamically with an `http.Handler` or hook into the request chain with an `asset
 Not all features of an `http.Request` are currently supported, please see the following feature matrix:
 
 | Feature                 | Win | Mac | Lin    |
-| ----------------------- | --- | --- | --- |
+| ----------------------- | --- | --- | ------ |
 | GET                     | ✅  | ✅  | ✅      |
-| POST                    | ✅  | ✅  | ❌  |
-| PUT                     | ✅  | ✅  | ❌  |
-| PATCH                   | ✅  | ✅  | ❌  |
-| DELETE                  | ✅  | ✅  | ❌  |
-| Request Headers         | ✅  | ✅  | ❌  |
+| POST                    | ✅  | ✅  | ✅ [^1] |
+| PUT                     | ✅  | ✅  | ✅ [^1] |
+| PATCH                   | ✅  | ✅  | ✅ [^1] |
+| DELETE                  | ✅  | ✅  | ✅ [^1] |
+| Request Headers         | ✅  | ✅  | ✅ [^1] |
 | Request Body            | ✅  | ✅  | ❌      |
 | Request Body Streaming  | ❌  | ❌  | ❌      |
-| Response StatusCodes    | ✅  | ✅  | ❌  |
-| Response Headers        | ✅  | ✅  | ❌  |
+| Response StatusCodes    | ✅  | ✅  | ✅ [^1] |
+| Response Headers        | ✅  | ✅  | ✅ [^1] |
 | Response Body           | ✅  | ✅  | ✅      |
 | Response Body Streaming | ❌  | ❌  | ✅      |
 | WebSockets              | ❌  | ❌  | ❌      |
+| HTTP Redirects 30x      | ✅  | ❌  | ❌      |
 
-NOTE: Linux is currently very limited due to targeting a WebKit2GTK Version < 2.36.0. In the future some features will be
-supported by the introduction of WebKit2GTK 2.36.0+ support.
+[^1]: This requires WebKit2GTK 2.36+ support and your app needs to be build with the  build tag `webkit2_36` to activate support for this feature. This also bumps the minimum requirement of WebKit2GTK to 2.36 for your app.
 
 Name: AssetServer<br/>
 Type: `*assetserver.Options`

website/src/pages/changelog.mdx

@@ -21,6 +21,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Add new property for the `wails.json` config file - `bindings`. More information on the new property can be found in the updated [schema](/schemas/config.v2.json). Properties `prefix` and `suffix` allow you to control the generated TypeScript entity name in the `model.ts` file. Added by @OlegGulevskyy in [PR](https://github.com/wailsapp/wails/pull/2101)
 - The `WindowSetAlwaysOnTop` method is now exposed in the JS runtime. Fixed by @gotid in [PR](https://github.com/wailsapp/wails/pull/2128)
 - The [AssetServer](/docs/reference/options#assetserver) now supports serving the index.html file when requesting a directory. Added by @stffabi in [PR](https://github.com/wailsapp/wails/pull/2110)
+- Added support for WebKit2GTK 2.36+ on Linux. This brings additional features for the [AssetServer](/docs/reference/options#assetserver), like support for HTTP methods and Headers. The app must be compiled with the Go build tag `webkit2_36` to activate support for this features. This also bumps the minimum requirement of WebKit2GTK to 2.36 for your app. Fixed by @stffabi in this [PR](https://github.com/wailsapp/wails/pull/2151)
 
 ### Fixed
 - The `noreload` flag in wails dev wasn't applied. Fixed by @stffabi in this [PR](https://github.com/wailsapp/wails/pull/2081)