straightened out error handling so we don't wind up with a bunch of panics clogging the debug console

ui/amcontext.go

@@ -549,34 +549,37 @@ func newContext(ctxt echo.Context) (*amContext, error) {
 
 	rc.echoContext = ctxt
 	ctxt.Set("__amsterdam_context", rc)
-	store := ctxt.Get("AmSessionStore").(AmSessionStore)
-	sess, err := store.Get(ctxt.Request(), "AMSTERDAM_SESSION")
-	if err == nil {
-		rc.session = sess
-		sess.SetOptions(defoptions)
-		if sess.IsNew() {
-			sess.FirstTime(ctxt.Request().Context())
-		} else {
-			sess.Hit()
-		}
-	}
-	id, ok := sess.Uid()
-	if ok {
-		rc.user, err = database.AmGetUser(ctxt.Request().Context(), id)
+	stmp := ctxt.Get("AmSessionStore")
+	if stmp != nil {
+		store := stmp.(AmSessionStore)
+		sess, err := store.Get(ctxt.Request(), "AMSTERDAM_SESSION")
 		if err == nil {
-			rc.effectiveLevel = rc.user.BaseLevel
+			rc.session = sess
+			sess.SetOptions(defoptions)
+			if sess.IsNew() {
+				sess.FirstTime(ctxt.Request().Context())
+			} else {
+				sess.Hit()
+			}
+		}
+		id, ok := sess.Uid()
+		if ok {
+			rc.user, err = database.AmGetUser(ctxt.Request().Context(), id)
+			if err == nil {
+				rc.effectiveLevel = rc.user.BaseLevel
+			} else {
+				rc.user = nil
+				rc.effectiveLevel = database.AmRole("NotInList").Level()
+			}
 		} else {
 			rc.user = nil
 			rc.effectiveLevel = database.AmRole("NotInList").Level()
 		}
-	} else {
-		rc.user = nil
-		rc.effectiveLevel = database.AmRole("NotInList").Level()
-	}
-	if rc.user != nil && !rc.user.IsAnon {
-		cp, ok := sess.Get("lastCommunity")
-		if ok {
-			rc.SetCommunityContext(fmt.Sprintf("%d", cp))
+		if rc.user != nil && !rc.user.IsAnon {
+			cp, ok := sess.Get("lastCommunity")
+			if ok {
+				rc.SetCommunityContext(fmt.Sprintf("%d", cp))
+			}
 		}
 	}
 	return rc, err

ui/render_wrap.go

@@ -114,11 +114,16 @@ func AmSendPageData(ctxt echo.Context, amctxt AmContext, command string, data an
 		case "top":
 			menus[0] = AmMenu("top")
 		case "community":
-			md, err := AmBuildCommunityMenu(ctxt.Request().Context(), amctxt.CurrentCommunity())
-			if err != nil {
-				return err
+			comm := amctxt.CurrentCommunity()
+			if comm != nil {
+				md, err := AmBuildCommunityMenu(ctxt.Request().Context(), comm)
+				if err != nil {
+					return err
+				}
+				menus[0] = md
+			} else {
+				menus[0] = AmMenu("top")
 			}
-			menus[0] = md
 		default:
 			return fmt.Errorf("AmSendPageData(): unknown left menu context: %s", amctxt.LeftMenu())
 		}
@@ -175,3 +180,40 @@ func AmWrap(myfunc AmPageFunc) echo.HandlerFunc {
 		return nil
 	}
 }
+
+// AmWithTempContext runs a page function with a temporary context. Used in error handling.
+func AmWithTempContext(c echo.Context, fn AmPageFunc) error {
+	var ctxt AmContext = nil
+	myctxt := c.Get("__amsterdam_context")
+	if myctxt != nil {
+		ac, ok := myctxt.(*amContext)
+		if ok {
+			ctxt = ac
+			ac.echoContext = c
+		}
+	}
+	if ctxt == nil {
+		ac, err := newContext(c)
+		if err != nil {
+			return err
+		}
+		ctxt = ac
+		defer func() {
+			amContextRecycleBin <- ac
+		}()
+	}
+
+	// Call the function
+	command, arg := fn(ctxt)
+
+	// Add the dynamic headers.
+	c.Response().Header().Set("Pragma", "No-cache")
+	c.Response().Header().Set("Cache-Control", "no-cache")
+	c.Response().Header().Set("Expires", expireTime)
+
+	if err := AmSendPageData(c, ctxt, command, arg); err != nil {
+		c.Logger().Errorf("Rendering error: %v", err)
+		return err
+	}
+	return nil
+}