Rework reader usage and fix loading dropped file

README.md

@@ -20,7 +20,7 @@ JSON Viewer is a desktop app for browsing large JSON files. It runs on Linux, Wi
 - Single executable file, no installation required
 - Desktop app that runs on Windows, Linux and macOS (experimental)
 - Automatic dark and light mode
-- Open JSON files from disk or clipboard
+- JSON files can be opened via file dialog, from clipboard or drag-and-drop
 
 ## Screenshots
 

internal/jsondocument/helper.go

@@ -0,0 +1,24 @@
+package jsondocument
+
+import (
+	"fmt"
+	"io"
+
+	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/storage"
+)
+
+// Creates and returns an URIReadCloser from a reader.
+func MakeURIReadCloser(r io.Reader, name string) uriReadCloser {
+	return uriReadCloser{io.NopCloser(r), name}
+}
+
+type uriReadCloser struct {
+	io.ReadCloser
+	name string
+}
+
+func (u uriReadCloser) URI() fyne.URI {
+	uri, _ := storage.ParseURI(fmt.Sprintf("dummy://dummy/%s", u.name))
+	return uri
+}

internal/jsondocument/helper_test.go

@@ -0,0 +1,15 @@
+package jsondocument_test
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/ErikKalkoken/jsonviewer/internal/jsondocument"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestHelper(t *testing.T) {
+	r := strings.NewReader("test")
+	r2 := jsondocument.MakeURIReadCloser(r, "alpha")
+	assert.Equal(t, "alpha", r2.URI().Name())
+}

internal/jsondocument/jsondocument.go

@@ -10,6 +10,7 @@ import (
 	"strconv"
 	"sync"
 
+	"fyne.io/fyne/v2"
 	"fyne.io/fyne/v2/data/binding"
 	"fyne.io/fyne/v2/widget"
 )
@@ -128,7 +129,8 @@ func (t *JSONDocument) Value(uid widget.TreeNodeID) Node {
 
 // Load loads JSON data from a reader and builds a new JSON document from it.
 // It reports it's current progress to the caller via updates to progressInfo.
-func (t *JSONDocument) Load(reader io.Reader, progressInfo binding.Untyped) error {
+func (t *JSONDocument) Load(reader fyne.URIReadCloser, progressInfo binding.Untyped) error {
+	defer reader.Close()
 	t.progressInfo = progressInfo
 	byt, err := t.loadFile(reader)
 	if err != nil {
@@ -291,15 +293,15 @@ func (t *JSONDocument) setProgressInfo(info ProgressInfo) error {
 	return nil
 }
 
-func (t *JSONDocument) loadFile(reader io.Reader) ([]byte, error) {
+func (t *JSONDocument) loadFile(reader fyne.URIReadCloser) ([]byte, error) {
 	if err := t.setProgressInfo(ProgressInfo{CurrentStep: 1}); err != nil {
 		return nil, err
 	}
 	dat, err := io.ReadAll(reader)
 	if err != nil {
-		return nil, fmt.Errorf("failed to read file: %s", err)
+		return nil, fmt.Errorf("failed to read file %s: %s", reader.URI(), err)
 	}
-	slog.Info("Read file")
+	slog.Info("Read file", "uri", reader.URI())
 	return dat, nil
 }
 
@@ -309,9 +311,9 @@ func (t *JSONDocument) parseFile(dat []byte) (any, error) {
 	}
 	var data any
 	if err := json.Unmarshal(dat, &data); err != nil {
-		return nil, fmt.Errorf("failed to unmarshal JSON: %s", err)
+		return nil, fmt.Errorf("failed to unmarshal data: %s", err)
 	}
-	slog.Info("Unmarshaled JSON file")
+	slog.Info("Completed un-marshaling data")
 	return data, nil
 }
 

internal/jsondocument/jsondocument_internal_test.go

@@ -18,7 +18,7 @@ func TestLoadFile(t *testing.T) {
 		if err != nil {
 			t.Fatal(err)
 		}
-		r := bytes.NewReader(dat)
+		r := MakeURIReadCloser(bytes.NewReader(dat), "test")
 		// when
 		byt, err := j.loadFile(r)
 		if assert.NoError(t, err) {
@@ -31,7 +31,7 @@ func TestLoadFile(t *testing.T) {
 	})
 	t.Run("should return error when stream can not be unmarshaled", func(t *testing.T) {
 		// given
-		r := strings.NewReader("invalid JSON")
+		r := MakeURIReadCloser(strings.NewReader("invalid JSON"), "test")
 		// when
 		byt, err := j.loadFile(r)
 		if assert.NoError(t, err) {

internal/jsondocument/jsondocument_test.go

@@ -3,9 +3,9 @@ package jsondocument_test
 import (
 	"bytes"
 	"encoding/json"
-	"io"
 	"testing"
 
+	"fyne.io/fyne/v2"
 	"fyne.io/fyne/v2/data/binding"
 	"fyne.io/fyne/v2/widget"
 	"github.com/ErikKalkoken/jsonviewer/internal/jsondocument"
@@ -131,12 +131,11 @@ func TestJsonDocumentLoad(t *testing.T) {
 	})
 }
 
-func makeDataReader(data any) io.Reader {
+func makeDataReader(data any) fyne.URIReadCloser {
 	x, err := json.Marshal(data)
 	if err != nil {
 		panic(err)
 	}
 	r := bytes.NewReader(x)
-	return r
-
+	return jsondocument.MakeURIReadCloser(r, "test")
 }

internal/ui/menu.go

@@ -31,31 +31,27 @@ func (u *UI) makeMenu() *fyne.MainMenu {
 				if reader == nil {
 					return
 				}
-				defer reader.Close()
-				if err := u.loadDocument(reader); err != nil {
-					u.showErrorDialog("Failed to load document", err)
-					return
-				}
+				u.loadDocument(reader)
 			}, u.window)
 			dialogOpen.Show()
 		}),
 		recentItem,
 		fyne.NewMenuItem("Open From Clipboard", func() {
 			r := strings.NewReader(u.window.Clipboard().Content())
-			reader := makeURIReadCloser(r)
-			if err := u.loadDocument(reader); err != nil {
-				u.showErrorDialog("Failed to load JSON document from clipboard", err)
-				return
-			}
+			reader := jsondocument.MakeURIReadCloser(r, "CLIPBOARD")
+			u.loadDocument(reader)
 		}),
 		fyne.NewMenuItemSeparator(),
 		fyne.NewMenuItem("Reload", func() {
 			if u.currentFile == nil {
 				return
 			}
-			if err := u.loadURI(u.currentFile); err != nil {
+			reader, err := storage.Reader(u.currentFile)
+			if err != nil {
 				u.showErrorDialog("Failed to reload file", err)
+				return
 			}
+			u.loadDocument(reader)
 		}),
 	)
 	viewMenu := fyne.NewMenu("View",
@@ -122,30 +118,16 @@ func (u *UI) updateRecentFilesMenu() {
 				dialog.ShowError(err, u.window)
 				return
 			}
-			defer reader.Close()
-			if err := u.loadDocument(reader); err != nil {
-				dialog.ShowError(err, u.window)
-				return
-			}
+			u.loadDocument(reader)
 		})
 	}
 	u.fileMenu.Items[1].ChildMenu.Items = items
 	u.fileMenu.Refresh()
 }
 
-func (u *UI) loadURI(uri fyne.URI) error {
-	reader, err := storage.Reader(uri)
-	if err != nil {
-		return err
-	}
-	if err := u.loadDocument(reader); err != nil {
-		return err
-	}
-	return nil
-}
-
-func (u *UI) loadDocument(reader fyne.URIReadCloser) error {
-	defer reader.Close()
+// loadDocument loads a JSON file
+// Shows a loader modal while loading
+func (u *UI) loadDocument(reader fyne.URIReadCloser) {
 	infoText := widget.NewLabel("")
 	pb1 := widget.NewProgressBarInfinite()
 	pb2 := widget.NewProgressBar()
@@ -187,25 +169,25 @@ func (u *UI) loadDocument(reader fyne.URIReadCloser) error {
 	c := container.NewVBox(infoText, container.NewStack(pb1, pb2))
 	d2 := dialog.NewCustomWithoutButtons("Loading", c, u.window)
 	d2.Show()
-	defer d2.Hide()
-	if err := u.document.Load(reader, progressInfo); err != nil {
-		return err
-	}
-	p := message.NewPrinter(language.English)
-	out := p.Sprintf("%d elements", u.document.Size())
-	u.statusTreeSize.SetText(out)
-	u.welcomeMessage.Hide()
-	u.treeWidget.Refresh()
-	u.detailCopyValue.Show()
-	x := reader.URI()
-	if x != nil {
-		u.setTitle(x.Name())
-		u.addRecentFile(x)
-	} else {
-		u.setTitle("CLIPBOARD")
-	}
-	u.currentFile = x
-	return nil
+	go func() {
+		defer d2.Hide()
+		if err := u.document.Load(reader, progressInfo); err != nil {
+			u.showErrorDialog("Failed to load document", err)
+			return
+		}
+		p := message.NewPrinter(language.English)
+		out := p.Sprintf("%d elements", u.document.Size())
+		u.statusTreeSize.SetText(out)
+		u.welcomeMessage.Hide()
+		u.treeWidget.Refresh()
+		u.detailCopyValue.Show()
+		uri := reader.URI()
+		if uri.Scheme() == "file" {
+			u.addRecentFile(uri)
+		}
+		u.setTitle(uri.Name())
+		u.currentFile = uri
+	}()
 }
 
 func (u *UI) showAboutDialog() {

internal/ui/ui.go

@@ -104,20 +104,18 @@ func NewUI() (*UI, error) {
 	u.window.SetMainMenu(u.makeMenu())
 	u.updateRecentFilesMenu()
 	u.window.SetMaster()
-	u.window.SetOnDropped(func(p fyne.Position, uri []fyne.URI) {
-		if len(uri) < 1 {
+	u.window.SetOnDropped(func(p fyne.Position, uris []fyne.URI) {
+		if len(uris) < 1 {
 			return
 		}
-		x := uri[0].String()
-		x2, err := storage.ParseURI(x)
+		uri := uris[0]
+		slog.Info("Loading dropped file", "uri", uri)
+		reader, err := storage.Reader(uri)
 		if err != nil {
-			slog.Error("Failed to identify dropped file", "err", err)
+			u.showErrorDialog(fmt.Sprintf("Failed to load file: %s", uri), err)
 			return
 		}
-		slog.Info("Loading dropped file", "uri", x2)
-		if err := u.loadURI(x2); err != nil {
-			u.showErrorDialog("Failed to load file", err)
-		}
+		u.loadDocument(reader)
 	})
 	s := fyne.Size{
 		Width:  float32(a.Preferences().FloatWithFallback(settingWindowWidth, 800)),

main.go

@@ -37,6 +37,7 @@ func main() {
 	levelFlag := logLevelFlag{value: slog.LevelWarn}
 	flag.Var(&levelFlag, "loglevel", "set log level")
 	flag.Parse()
+	log.SetFlags(log.LstdFlags | log.Llongfile)
 	slog.SetLogLoggerLevel(levelFlag.value)
 	u, err := ui.NewUI()
 	if err != nil {