WASM: Store User Files in localStorage

* In WASM build, user levels and doodads are written to localStorage
  using their userdir path as keys (".config/levels/test.level")
* LoadFile() and WriteFile() for both Levels and Doodads interact with
  the localStorage for WASM build instead of filesystem for desktop.
* userdir.ListLevels() and ListDoodads() for WASM scan the localStorage
  keys for file names.
* userdir.ResolvePath() now works for WASM (previously was dummied out),
  checks for the file in localStorage.

.gitignore

@@ -6,6 +6,7 @@ dist/
 wasm/assets/
 *.wasm
 *.doodad
+*.level
 docker/ubuntu
 docker/debian
 docker/fedora

pkg/config.go

@@ -43,12 +43,8 @@ func (d *Doodle) EditFile(filename string) error {
 			return d.EditDrawing(filename)
 		}
 
-		// WASM: no filesystem access, can go no further.
-		if runtime.GOOS == "js" {
-			return fmt.Errorf("EditFile(%s): not found for WASM and can go no further", filename)
-		}
-
-		// Check the user's levels directory.
+		// Check the user's levels directory. In WASM this will check in
+		// localStorage.
 		if foundFilename := userdir.ResolvePath(filename, extension, false); foundFilename != "" {
 			log.Info("EditFile: resolved name '%s' to path %s", filename, foundFilename)
 			absPath = foundFilename

pkg/doodads/fmt_readwrite.go

@@ -68,6 +68,14 @@ func LoadFile(filename string) (*Doodad, error) {
 
 	// WASM: try the file over HTTP ajax request.
 	if runtime.GOOS == "js" {
+		if result, ok := wasm.GetSession(filename); ok {
+			log.Info("recall doodad data from localStorage")
+			return FromJSON(filename, []byte(result))
+		}
+
+		// TODO: ajax load for doodads might not work, filesystem.FindFile returns
+		// the base file for WASM but for now force it to system doodads path
+		filename = "assets/doodads/" + filename
 		jsonData, err := wasm.HTTPGet(filename)
 		if err != nil {
 			return nil, err
@@ -90,13 +98,19 @@ func (d *Doodad) WriteFile(filename string) error {
 	d.Version = 1
 	d.GameVersion = branding.Version
 
-	// bin, err := m.ToBinary()
 	bin, err := d.ToJSON()
 	if err != nil {
 		return err
 	}
 
-	// Save it to their profile directory.
+	// WASM: place in localStorage.
+	if runtime.GOOS == "js" {
+		log.Info("wasm: write %s to localStorage", filename)
+		wasm.SetSession(filename, string(bin))
+		return nil
+	}
+
+	// Desktop: write to disk.
 	filename = userdir.DoodadPath(filename)
 	log.Info("Write Doodad: %s", filename)
 	err = ioutil.WriteFile(filename, bin, 0644)

pkg/filesystem/filesystem.go

@@ -105,7 +105,7 @@ func FindFile(filename string) (string, error) {
 		// WASM: can't check the filesystem. Let the caller go ahead and try
 		// loading via ajax request.
 		if runtime.GOOS == "js" {
-			return candidate, nil
+			return filename, nil
 		}
 
 		// external system level?
@@ -133,7 +133,7 @@ func FindFile(filename string) (string, error) {
 		// WASM: can't check the filesystem. Let the caller go ahead and try
 		// loading via ajax request.
 		if runtime.GOOS == "js" {
-			return candidate, nil
+			return filename, nil
 		}
 
 		// external system doodad?

pkg/level/fmt_readwrite.go

@@ -61,8 +61,14 @@ func LoadFile(filename string) (*Level, error) {
 		return FromJSON(filename, jsonData)
 	}
 
-	// WASM: try the file over HTTP ajax request.
+	// WASM: try the file from localStorage or HTTP ajax request.
 	if runtime.GOOS == "js" {
+		if result, ok := wasm.GetSession(filename); ok {
+			log.Info("recall level data from localStorage")
+			return FromJSON(filename, []byte(result))
+		}
+
+		// Ajax request.
 		jsonData, err := wasm.HTTPGet(filename)
 		if err != nil {
 			return nil, err
@@ -98,7 +104,6 @@ func (m *Level) WriteFile(filename string) error {
 	m.Version = 1
 	m.GameVersion = branding.Version
 
-	// bin, err := m.ToBinary()
 	bin, err := m.ToJSON()
 	if err != nil {
 		return err
@@ -107,6 +112,15 @@ func (m *Level) WriteFile(filename string) error {
 	// Save it to their profile directory.
 	filename = userdir.LevelPath(filename)
 	log.Info("Write Level: %s", filename)
+
+	// WASM: place in localStorage.
+	if runtime.GOOS == "js" {
+		log.Info("wasm: write %s to localStorage", filename)
+		wasm.SetSession(filename, string(bin))
+		return nil
+	}
+
+	// Desktop: write to disk.
 	err = ioutil.WriteFile(filename, bin, 0644)
 	if err != nil {
 		return fmt.Errorf("level.WriteFile: %s", err)

pkg/userdir/userdir.go

@@ -7,7 +7,7 @@ import (
 	"runtime"
 	"strings"
 
-	"git.kirsle.net/apps/doodle/pkg/log"
+	"git.kirsle.net/apps/doodle/pkg/wasm"
 	"github.com/kirsle/configdir"
 )
 
@@ -77,6 +77,11 @@ func CacheFilename(filename ...string) string {
 func ListDoodads() ([]string, error) {
 	var names []string
 
+	// WASM: list from localStorage.
+	if runtime.GOOS == "js" {
+		return wasm.StorageKeys(DoodadDirectory + "/"), nil
+	}
+
 	files, err := ioutil.ReadDir(DoodadDirectory)
 	if err != nil {
 		return names, err
@@ -96,6 +101,11 @@ func ListDoodads() ([]string, error) {
 func ListLevels() ([]string, error) {
 	var names []string
 
+	// WASM: list from localStorage.
+	if runtime.GOOS == "js" {
+		return wasm.StorageKeys(LevelDirectory + "/"), nil
+	}
+
 	files, err := ioutil.ReadDir(LevelDirectory)
 	if err != nil {
 		return names, err
@@ -133,15 +143,11 @@ func resolvePath(directory, filename, extension string) string {
 // existed. So the filename should have a ".level" or ".doodad" extension and
 // then this path will resolve the ProfileDirectory of the file.
 func ResolvePath(filename, extension string, one bool) string {
-	// WASM has no file system.
-	if runtime.GOOS == "js" {
-		log.Error("userdir.ResolvePath: not supported in WASM build")
-		return ""
-	}
-
 	// If the filename exists outright, return it.
-	if _, err := os.Stat(filename); !os.IsNotExist(err) {
-		return filename
+	if !(runtime.GOOS == "js") {
+		if _, err := os.Stat(filename); !os.IsNotExist(err) {
+			return filename
+		}
 	}
 
 	var paths []string
@@ -157,6 +163,15 @@ func ResolvePath(filename, extension string, one bool) string {
 	}
 
 	for _, test := range paths {
+		// WASM: check the path in localStorage.
+		if runtime.GOOS == "js" {
+			if _, ok := wasm.GetSession(test); ok {
+				return test
+			}
+			continue
+		}
+
+		// Desktop: test the filesystem.
 		if _, err := os.Stat(test); os.IsNotExist(err) {
 			continue
 		}

pkg/wasm/localstorage.go

@@ -2,6 +2,12 @@
 
 package wasm
 
+// StorageKeys returns the list of localStorage keys matching a prefix.
+// This is a no-op when not in wasm.
+func StorageKeys(prefix string) []string {
+	return []string{}
+}
+
 // SetSession sets a binary value on sessionStorage.
 // This is a no-op when not in wasm.
 func SetSession(key string, value string) {

pkg/wasm/localstorage_js.go

@@ -3,20 +3,37 @@
 package wasm
 
 import (
+	"strings"
 	"syscall/js"
+
+	"git.kirsle.net/apps/doodle/pkg/log"
 )
 
+// StorageKeys returns the list of localStorage keys matching a prefix.
+func StorageKeys(prefix string) []string {
+	keys := js.Global().Get("Object").Call("keys", js.Global().Get("localStorage"))
+
+	var result []string
+	for i := 0; i < keys.Length(); i++ {
+		value := keys.Index(i).String()
+		if strings.HasPrefix(value, prefix) {
+			result = append(result,
+				strings.TrimPrefix(keys.Index(i).String(), prefix),
+			)
+		}
+	}
+	log.Info("LS KEYS: %+v", result)
+	return result
+}
+
 // SetSession sets a text value on sessionStorage.
 func SetSession(key string, value string) {
-	// b64 := base64.StdEncoding.EncodeToString(value)
-	panic("SesSession: " + key)
-	js.Global().Get("sessionStorage").Call("setItem", key, value)
+	js.Global().Get("localStorage").Call("setItem", key, value)
 }
 
 // GetSession retrieves a text value from sessionStorage.
 func GetSession(key string) (string, bool) {
-	panic("GetSession: " + key)
 	var value js.Value
-	value = js.Global().Get("sessionStorage").Call("getItem", key)
+	value = js.Global().Get("localStorage").Call("getItem", key)
 	return value.String(), value.Type() == js.TypeString
 }