db: return error from RenderForNav, contextAction.Callback

db_badger.go

@@ -33,7 +33,7 @@ func (ld *badgerLoadedDatabase) Keepalive(ndata *navData) {
 	ld.arena = append(ld.arena, ndata)
 }
 
-func (ld *badgerLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
+func (ld *badgerLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) error {
 
 	// Load properties
 
@@ -74,13 +74,13 @@ func (ld *badgerLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
 		return nil
 	})
 	if err != nil {
-		vcl.ShowMessage(fmt.Sprintf("Failed to load data: %s", err.Error()))
+		return err
-		return
 	}
 
 	// Valid
 	vcl_stringgrid_columnwidths(f.contentBox)
 	f.contentBox.SetEnabled(true)
+	return nil
 }
 
 func (n *badgerLoadedDatabase) ApplyChanges(f *TMainForm, ndata *navData) error {

db_bolt.go

@@ -39,7 +39,7 @@ func (ld *boltLoadedDatabase) Keepalive(ndata *navData) {
 	ld.arena = append(ld.arena, ndata)
 }
 
-func (ld *boltLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
+func (ld *boltLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) error {
 
 	// Load properties
 
@@ -72,13 +72,13 @@ func (ld *boltLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
 		return nil
 	})
 	if err != nil {
-		vcl.ShowMessage(fmt.Sprintf("Failed to load data for bucket %q: %s", bucketDisplayName, err.Error()))
+		return err
-		return
 	}
 
 	// Valid
 	vcl_stringgrid_columnwidths(f.contentBox)
 	f.contentBox.SetEnabled(true)
+	return nil
 }
 
 func (n *boltLoadedDatabase) ApplyChanges(f *TMainForm, ndata *navData) error {
@@ -143,13 +143,14 @@ func (ld *boltLoadedDatabase) NavContext(ndata *navData) (ret []contextAction, e
 	if len(ndata.bucketPath) > 0 {
 		ret = append(ret, contextAction{"Delete bucket", ld.DeleteBucket})
 	}
+
 	return
 }
 
-func (ld *boltLoadedDatabase) AddChildBucket(ndata *navData) {
+func (ld *boltLoadedDatabase) AddChildBucket(ndata *navData) error {
 	bucketName := ""
 	if !vcl.InputQuery(APPNAME, "Enter a name for the new bucket:", &bucketName) {
-		return // cancel
+		return nil // cancel
 	}
 
 	err := ld.db.Update(func(tx *bbolt.Tx) error {
@@ -164,11 +165,12 @@ func (ld *boltLoadedDatabase) AddChildBucket(ndata *navData) {
 		return err
 	})
 	if err != nil {
-		vcl.ShowMessageFmt("Error adding bucket: %v", err)
+		return fmt.Errorf("Error adding bucket: %w", err)
 	}
+	return nil
 }
 
-func (ld *boltLoadedDatabase) DeleteBucket(ndata *navData) {
+func (ld *boltLoadedDatabase) DeleteBucket(ndata *navData) error {
 	err := ld.db.Update(func(tx *bbolt.Tx) error {
 		// Find parent of this bucket.
 		if len(ndata.bucketPath) >= 2 {
@@ -181,8 +183,9 @@ func (ld *boltLoadedDatabase) DeleteBucket(ndata *navData) {
 		}
 	})
 	if err != nil {
-		vcl.ShowMessageFmt("Error deleting bucket %q: %v", strings.Join(ndata.bucketPath, `/`), err)
+		return fmt.Errorf("Error deleting bucket %q: %w", strings.Join(ndata.bucketPath, `/`), err)
 	}
+	return nil
 }
 
 func (ld *boltLoadedDatabase) ExecQuery(query string, resultArea *vcl.TStringGrid) error {

db_debconf.go

@@ -35,7 +35,7 @@ func (ld *debconfLoadedDatabase) Keepalive(ndata *navData) {
 	ld.arena = append(ld.arena, ndata)
 }
 
-func (ld *debconfLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
+func (ld *debconfLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) error {
 
 	// Load properties
 
@@ -67,6 +67,7 @@ func (ld *debconfLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
 	// Valid
 	vcl_stringgrid_columnwidths(f.contentBox)
 	f.contentBox.SetEnabled(true)
+	return nil
 }
 
 func (n *debconfLoadedDatabase) ApplyChanges(f *TMainForm, ndata *navData) error {

db_none.go

@@ -18,8 +18,9 @@ func (n *noLoadedDatabase) RootElement() *vcl.TTreeNode {
 	return nil
 }
 
-func (n *noLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
+func (n *noLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) error {
 	f.propertiesBox.SetText("Open a database to get started...")
+	return nil
 }
 
 func (n *noLoadedDatabase) ApplyChanges(f *TMainForm, ndata *navData) error {

db_pebble.go

@@ -35,7 +35,7 @@ func (ld *pebbleLoadedDatabase) Keepalive(ndata *navData) {
 	ld.arena = append(ld.arena, ndata)
 }
 
-func (ld *pebbleLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
+func (ld *pebbleLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) error {
 
 	ctx := context.Background()
 
@@ -59,8 +59,7 @@ func (ld *pebbleLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
 		k := itr.Key()
 		v, err := itr.ValueAndErr()
 		if err != nil {
-			vcl.ShowMessage(fmt.Sprintf("Failed to load data for key %q: %s", formatAny(k), err.Error()))
+			return fmt.Errorf("Failed to load data for key %q: %w", formatAny(k), err)
-			return
 		}
 
 		rpos := f.contentBox.RowCount()
@@ -72,6 +71,7 @@ func (ld *pebbleLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
 	// Valid
 	vcl_stringgrid_columnwidths(f.contentBox)
 	f.contentBox.SetEnabled(true)
+	return nil
 }
 
 func (n *pebbleLoadedDatabase) ApplyChanges(f *TMainForm, ndata *navData) error {

db_redis.go

@@ -40,34 +40,32 @@ func (ld *redisLoadedDatabase) Keepalive(ndata *navData) {
 	ld.arena = append(ld.arena, ndata)
 }
 
-func (ld *redisLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
+func (ld *redisLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) error {
 	ctx := context.Background()
 
 	if len(ndata.bucketPath) == 0 {
 		// Top-level: Show info() on main Properties tab
 		infostr, err := ld.db.Info(ctx).Result()
 		if err != nil {
-			vcl.ShowMessage(fmt.Sprintf("Retreiving database info: %v", err))
+			return fmt.Errorf("Retreiving database info: %w", err)
-			return
 		}
 
 		f.propertiesBox.SetText(infostr)
 
 		// Leave data tab disabled (default behaviour)
+		return nil
 
 	} else if len(ndata.bucketPath) == 1 {
 		// One selected database
 		// Figure out its content
 		err := ld.db.Do(ctx, "SELECT", ndata.bucketPath[0]).Err()
 		if err != nil {
-			vcl.ShowMessage(fmt.Sprintf("Switching to database %q: %v", ndata.bucketPath[0], err))
+			return fmt.Errorf("Switching to database %q: %w", ndata.bucketPath[0], err)
-			return
 		}
 
 		allKeys, err := ld.db.Keys(ctx, "*").Result()
 		if err != nil {
-			vcl.ShowMessage(fmt.Sprintf("Listing keys in database %q: %v", ndata.bucketPath[0], err))
+			return fmt.Errorf("Listing keys in database %q: %w", ndata.bucketPath[0], err)
-			return
 		}
 
 		f.propertiesBox.SetText(fmt.Sprintf("Database %s\nTotal keys: %d\n", ndata.bucketPath[0], len(allKeys)))
@@ -84,8 +82,7 @@ func (ld *redisLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
 		for _, key := range allKeys {
 			typeName, err := ld.db.Type(ctx, key).Result()
 			if err != nil {
-				vcl.ShowMessage(fmt.Sprintf("Loading %q/%q: %v", ndata.bucketPath[0], key, err))
+				return fmt.Errorf("Loading %q/%q: %w", ndata.bucketPath[0], key, err)
-				return
 			}
 
 			rpos := f.contentBox.RowCount()
@@ -97,16 +94,14 @@ func (ld *redisLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
 			case "string":
 				val, err := ld.db.Get(ctx, key).Result()
 				if err != nil {
-					vcl.ShowMessage(fmt.Sprintf("Loading %q/%q: %v", ndata.bucketPath[0], key, err))
+					return fmt.Errorf("Loading %q/%q: %w", ndata.bucketPath[0], key, err)
-					return
 				}
 				f.contentBox.SetCells(2, rpos, val)
 
 			case "hash":
 				val, err := ld.db.HGetAll(ctx, key).Result()
 				if err != nil {
-					vcl.ShowMessage(fmt.Sprintf("Loading %q/%q: %v", ndata.bucketPath[0], key, err))
+					return fmt.Errorf("Loading %q/%q: %w", ndata.bucketPath[0], key, err)
-					return
 				}
 				// It's a map[string]string
 				f.contentBox.SetCells(2, rpos, formatAny(val))
@@ -129,10 +124,10 @@ func (ld *redisLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
 		// Valid
 		vcl_stringgrid_columnwidths(f.contentBox)
 		f.contentBox.SetEnabled(true)
+		return nil
 
 	} else {
-		vcl.ShowMessage(fmt.Sprintf("Unexpected nav position %q", ndata.bucketPath))
+		return fmt.Errorf("Unexpected nav position %q", ndata.bucketPath)
-		return
 
 	}
 }

db_sqlite.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"database/sql"
+	"errors"
 	"fmt"
 	"path/filepath"
 	"unsafe"
@@ -36,15 +37,17 @@ func (ld *sqliteLoadedDatabase) Keepalive(ndata *navData) {
 	ld.arena = append(ld.arena, ndata)
 }
 
-func (ld *sqliteLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
+func (ld *sqliteLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) error {
 
 	if len(ndata.bucketPath) == 0 {
 		// Top-level
 		f.propertiesBox.SetText("Please select...")
+		return nil
 
 	} else if len(ndata.bucketPath) == 1 {
 		// Category (tables, ...)
 		f.propertiesBox.SetText("Please select...")
+		return nil
 
 	} else if len(ndata.bucketPath) == 2 && ndata.bucketPath[0] == sqliteTablesCaption {
 		// Render for specific table
@@ -67,8 +70,7 @@ func (ld *sqliteLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
 		// work even when there are 0 results
 		columnNames, err := ld.sqliteGetColumnNamesForTable(tableName)
 		if err != nil {
-			vcl.ShowMessageFmt("Failed to load columns for table %q: %s", tableName, err.Error())
+			return fmt.Errorf("Failed to load columns for table %q: %w", tableName)
-			return
 		}
 
 		populateColumns(columnNames, f.contentBox)
@@ -79,8 +81,7 @@ func (ld *sqliteLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
 		// Select * with small limit
 		datar, err := ld.db.Query(`SELECT * FROM "` + tableName + `" LIMIT 1000`) // WARNING can't prepare this parameter, but it comes from the DB (trusted)
 		if err != nil {
-			vcl.ShowMessageFmt("Failed to load data for table %q: %s", tableName, err.Error())
+			return fmt.Errorf("Failed to load data for table %q: %w", tableName, err)
-			return
 		}
 		defer datar.Close()
 		populateRows(datar, f.contentBox)
@@ -88,9 +89,11 @@ func (ld *sqliteLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) {
 		// We successfully populated the data grid
 		vcl_stringgrid_columnwidths(f.contentBox)
 		f.contentBox.SetEnabled(true)
+		return nil
 
 	} else {
 		// ??? unknown
+		return errors.New("?")
 
 	}
 

loadedDatabase.go

@@ -11,7 +11,7 @@ var ErrNotSupported error = errors.New("Unsupported action for this database typ
 
 type contextAction struct {
 	Name     string
-	Callback func(ndata *navData)
+	Callback func(ndata *navData) error
 }
 
 // loadedDatabase is a DB-agnostic interface for each loaded database.
@@ -19,7 +19,7 @@ type loadedDatabase interface {
 	DisplayName() string
 	DriverName() string
 	RootElement() *vcl.TTreeNode
-	RenderForNav(f *TMainForm, ndata *navData)
+	RenderForNav(f *TMainForm, ndata *navData) error
 	ApplyChanges(f *TMainForm, ndata *navData) error
 	ExecQuery(query string, resultArea *vcl.TStringGrid) error
 	NavChildren(ndata *navData) ([]string, error)

main.go

@@ -507,7 +507,10 @@ func (f *TMainForm) OnNavContextPopup(sender vcl.IObject, mousePos types.TPoint,
 			mnuAction.SetCaption(action.Name)
 			cb := action.Callback // Copy to avoid reuse of loop variable
 			mnuAction.SetOnClick(func(sender vcl.IObject) {
-				cb(ndata)
+				err = cb(ndata)
+				if err != nil {
+					vcl.ShowMessage(err.Error())
+				}
 				f.OnNavContextRefresh(curItem, ndata)
 			})
 			mnu.Items().Add(mnuAction)
@@ -779,7 +782,13 @@ func (f *TMainForm) OnNavChange(sender vcl.IObject, node *vcl.TTreeNode) {
 	f.propertiesBox.Clear()
 	vcl_stringgrid_clear(f.contentBox)
 
-	ld.RenderForNav(f, ndata) // Handover to the database type's own renderer function
+	err := ld.RenderForNav(f, ndata) // Handover to the database type's own renderer function
+	if err != nil {
+		vcl.ShowMessage(err.Error())
+
+		// Ensure elements are disabled
+		f.contentBox.SetEnabled(false)
+	}
 
 	// We're in charge of common status bar text updates
 	f.StatusBar.SetSimpleText(ld.DisplayName() + " | " + ld.DriverName())