Reorder startup sequence

Add plugin scripts to asset server
Add InjectJS support in plugins

v2/pkg/assetserver/assetserver.go

@@ -2,8 +2,11 @@ package assetserver
 
 import (
 	"bytes"
+	"fmt"
+	"math/rand"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 
 	"golang.org/x/net/html"
 
@@ -42,6 +45,9 @@ type AssetServer struct {
 	// Use http based runtime
 	runtimeHandler RuntimeHandler
 
+	// plugin scripts
+	pluginScripts map[string]string
+
 	assetServerWebView
 }
 
@@ -89,6 +95,16 @@ func (d *AssetServer) UseRuntimeHandler(handler RuntimeHandler) {
 	d.runtimeHandler = handler
 }
 
+func (d *AssetServer) AddPluginScript(pluginName string, script string) {
+	if d.pluginScripts == nil {
+		d.pluginScripts = make(map[string]string)
+	}
+	pluginName = strings.ReplaceAll(pluginName, "/", "_")
+	pluginName = html.EscapeString(pluginName)
+	pluginScriptName := fmt.Sprintf("/plugin_%s_%d.js", pluginName, rand.Intn(100000))
+	d.pluginScripts[pluginScriptName] = script
+}
+
 func (d *AssetServer) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	if isWebSocket(req) {
 		// Forward WebSockets to the distinct websocket handler if it exists
@@ -149,6 +165,11 @@ func (d *AssetServer) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 		d.writeBlob(rw, path, content)
 
 	default:
+		// Check if this is a plugin script
+		if script, ok := d.pluginScripts[path]; ok {
+			d.writeBlob(rw, path, []byte(script))
+			return
+		}
 		d.handler.ServeHTTP(rw, req)
 	}
 }
@@ -174,6 +195,13 @@ func (d *AssetServer) processIndexHTML(indexHTML []byte) ([]byte, error) {
 		return nil, err
 	}
 
+	// Inject plugins
+	for scriptName := range d.pluginScripts {
+		if err := insertScriptInHead(htmlNode, scriptName); err != nil {
+			return nil, err
+		}
+	}
+
 	var buffer bytes.Buffer
 	err = html.Render(&buffer, htmlNode)
 	if err != nil {

v3/V3 Changes.md

@@ -108,3 +108,75 @@ This attribute specifies which javascript event should trigger the action. The d
 <button data-wml-event="hover-box" data-wml-trigger="mouseover">Hover over me!</button>
 ```
 
+## Plugins
+
+Plugins are a way to extend the functionality of your Wails application.
+
+### Creating a plugin
+
+Plugins are standard Go structure that adhere to the following interface:
+
+```go
+type Plugin interface {
+    Name() string
+    Init(*application.App) error
+    Shutdown() 
+    CallableByJS() []string
+    InjectJS() string
+}
+```
+
+The `Name()` method returns the name of the plugin. This is used for logging purposes.
+
+The `Init(*application.App) error` method is called when the plugin is loaded. The `*application.App`
+parameter is the application that the plugin is being loaded into. Any errors will prevent
+the application from starting.
+
+The `Shutdown()` method is called when the application is shutting down.
+
+The `CallableByJS()` method returns a list of exported functions that can be called from
+the frontend. These method names must exactly match the names of the methods exported
+by the plugin.
+
+The `InjectJS()` method returns JavaScript that should be injected into all windows as they are created. This is useful for adding custom JavaScript functions that complement the plugin.
+
+### Tips
+
+#### Enums
+
+In Go, enums are often defined as a type and a set of constants. For example:
+
+```go
+type MyEnum int
+
+const (
+    MyEnumOne MyEnum = iota
+    MyEnumTwo
+    MyEnumThree
+)
+```
+
+Due to incompatibility between Go and JavaScript, custom types cannot be used in this way. The best strategy is to use a type alias for float64:
+
+```go
+type MyEnum = float64
+
+const (
+    MyEnumOne MyEnum = iota
+    MyEnumTwo
+    MyEnumThree
+)
+```
+
+In Javascript, you can then use the following:
+
+```js
+const MyEnum = {
+    MyEnumOne: 0,
+    MyEnumTwo: 1,
+    MyEnumThree: 2
+}
+```
+
+- Why use `float64`? Can't we use `int`? 
+  - Because JavaScript doesn't have a concept of `int`. Everything is a `number`, which translates to `float64` in Go. There are also restrictions on casting types in Go's reflection package, which means using `int` doesn't work. 

v3/examples/plugins/plugins/hashes/plugin.go

@@ -5,6 +5,7 @@ import (
 	"crypto/sha1"
 	"crypto/sha256"
 	"encoding/hex"
+
 	"github.com/wailsapp/wails/v3/pkg/application"
 )
 
@@ -32,6 +33,10 @@ func (r *Plugin) CallableByJS() []string {
 	}
 }
 
+func (r *Plugin) InjectJS() string {
+	return ""
+}
+
 // ---------------- Plugin Methods ----------------
 
 type Hashes struct {

v3/pkg/application/application.go

@@ -38,6 +38,7 @@ func New(appOptions Options) *App {
 		log:                       logger.New(appOptions.Logger.CustomLoggers...),
 		contextMenus:              make(map[string]*Menu),
 	}
+	globalApplication = result
 
 	if !appOptions.Logger.Silent {
 		result.log.AddOutput(&logger.Console{})
@@ -60,7 +61,24 @@ func New(appOptions Options) *App {
 	srv.UseRuntimeHandler(NewMessageProcessor())
 	result.assets = srv
 
-	globalApplication = result
+	result.bindings, err = NewBindings(appOptions.Bind)
+	if err != nil {
+		println("Fatal error in application initialisation: ", err.Error())
+		os.Exit(1)
+	}
+	err = result.bindings.AddPlugins(appOptions.Plugins)
+	if err != nil {
+		println("Fatal error in application initialisation: ", err.Error())
+		os.Exit(1)
+	}
+
+	result.plugins = NewPluginManager(appOptions.Plugins, srv)
+	err = result.plugins.Init()
+	if err != nil {
+		println("Fatal error in application initialisation: ", err.Error())
+		os.Exit(1)
+	}
+
 	return result
 }
 
@@ -318,20 +336,6 @@ func (a *App) Run() error {
 		}
 	}()
 
-	var err error
-	a.bindings, err = NewBindings(a.options.Bind)
-	if err != nil {
-		return err
-	}
-
-	a.plugins = NewPluginManager(a.options.Plugins)
-	err = a.plugins.Init()
-	if err != nil {
-		return err
-	}
-
-	a.bindings.AddPlugins(a.options.Plugins)
-
 	// run windows
 	for _, window := range a.windows {
 		go window.run()
@@ -348,7 +352,7 @@ func (a *App) Run() error {
 	// set the application Icon
 	a.impl.setIcon(a.options.Icon)
 
-	err = a.impl.run()
+	err := a.impl.run()
 	if err != nil {
 		return err
 	}

v3/pkg/application/bindings.go

@@ -2,10 +2,11 @@ package application
 
 import (
 	"fmt"
-	"github.com/samber/lo"
 	"reflect"
 	"runtime"
 	"strings"
+
+	"github.com/samber/lo"
 )
 
 type CallOptions struct {
@@ -174,7 +175,7 @@ func (b *Bindings) getMethods(value interface{}) ([]*BoundMethod, error) {
 
 		if isFunction(value) {
 			name := runtime.FuncForPC(reflect.ValueOf(value).Pointer()).Name()
-			return nil, fmt.Errorf("%s is a function, not a pointer to a struct. Wails v2 has deprecated the binding of functions. Please wrap your functions up in a struct and bind a pointer to that struct.", name)
+			return nil, fmt.Errorf("%s is a function, not a pointer to a struct. Wails v2 has deprecated the binding of functions. Please wrap your functions up in a struct and bind a pointer to that struct", name)
 		}
 
 		return nil, fmt.Errorf("not a pointer to a struct")

v3/pkg/application/plugins.go

@@ -1,5 +1,7 @@
 package application
 
+import "github.com/wailsapp/wails/v2/pkg/assetserver"
+
 type Plugin interface {
 	Name() string
 	Init(app *App) error
@@ -10,13 +12,14 @@ type Plugin interface {
 
 type PluginManager struct {
 	plugins     map[string]Plugin
+	assetServer *assetserver.AssetServer
 }
 
-func NewPluginManager(plugins map[string]Plugin) *PluginManager {
+func NewPluginManager(plugins map[string]Plugin, assetServer *assetserver.AssetServer) *PluginManager {
 	result := &PluginManager{
 		plugins:     plugins,
+		assetServer: assetServer,
 	}
-	globalApplication.OnWindowCreation(result.onWindowCreation)
 	return result
 }
 
@@ -28,7 +31,7 @@ func (p *PluginManager) Init() error {
 		}
 		injectJS := plugin.InjectJS()
 		if injectJS != "" {
-
+			p.assetServer.AddPluginScript(plugin.Name(), injectJS)
 		}
 		globalApplication.info("Plugin '%s' initialised", plugin.Name())
 	}
@@ -41,12 +44,3 @@ func (p *PluginManager) Shutdown() {
 		globalApplication.info("Plugin '%s' shutdown", plugin.Name())
 	}
 }
-
-func (p *PluginManager) onWindowCreation(window *WebviewWindow) {
-	for _, plugin := range p.plugins {
-		injectJS := plugin.InjectJS()
-		if injectJS != "" {
-			window.ExecJS(injectJS)
-		}
-	}
-}

v3/plugins/README.md

@@ -1,29 +0,0 @@
-# Plugins
-
-Plugins are a way to extend the functionality of your Wails application.
-
-## Creating a plugin
-
-Plugins are standard Go structure that adhere to the following interface:
-
-```go
-type Plugin interface {
-    Name() string
-    Init(*application.App) error
-    Shutdown() 
-    CallableByJS() []string
-}
-```
-
-The `Name()` method returns the name of the plugin. This is used for logging purposes.
-
-The `Init(*application.App) error` method is called when the plugin is loaded. The `*application.App` 
-parameter is the application that the plugin is being loaded into. Any errors will prevent
-the application from starting.
-
-The `Shutdown()` method is called when the application is shutting down. 
-
-The `CallableByJS()` method returns a list of exported functions that can be called from 
-the frontend. These method names must exactly match the names of the methods exported 
-by the plugin.
-

v3/plugins/TODO.md

@@ -1,3 +0,0 @@
-# TODO
-
-- [ ] Add InjectCSS() to the plugin API?

v3/plugins/browser/plugin.go

@@ -33,6 +33,10 @@ func (p *Plugin) CallableByJS() []string {
 	}
 }
 
+func (p *Plugin) InjectJS() string {
+	return ""
+}
+
 // ---------------- Plugin Methods ----------------
 
 func (p *Plugin) OpenURL(url string) error {

v3/plugins/kvstore/kvstore.go

@@ -2,11 +2,12 @@ package kvstore
 
 import (
 	"encoding/json"
-	"github.com/wailsapp/wails/v3/pkg/application"
-	"github.com/wailsapp/wails/v3/pkg/logger"
 	"io"
 	"os"
 	"sync"
+
+	"github.com/wailsapp/wails/v3/pkg/application"
+	"github.com/wailsapp/wails/v3/pkg/logger"
 )
 
 type KeyValueStore struct {
@@ -18,6 +19,10 @@ type KeyValueStore struct {
 	app      *application.App
 }
 
+func (kvs *KeyValueStore) InjectJS() string {
+	return ""
+}
+
 type Config struct {
 	Filename string
 	AutoSave bool
@@ -67,6 +72,10 @@ func (kvs *KeyValueStore) CallableByJS() []string {
 	}
 }
 
+func (p *Plugin) InjectJS() string {
+	return ""
+}
+
 // ---------------- Plugin Methods ----------------
 
 func (kvs *KeyValueStore) open(filename string) (err error) {

v3/plugins/log/plugin.go

@@ -1,18 +1,23 @@
 package log
 
 import (
+	_ "embed"
 	"fmt"
-	"github.com/wailsapp/wails/v3/pkg/application"
 	"io"
 	"os"
+
+	"github.com/wailsapp/wails/v3/pkg/application"
 )
 
+//go:embed plugin.js
+var pluginJS string
+
 // ---------------- Plugin Setup ----------------
 // This is the main plugin struct. It can be named anything you like.
 // It must implement the application.Plugin interface.
 // Both the Init() and Shutdown() methods are called synchronously when the app starts and stops.
 
-type LogLevel int
+type LogLevel = float64
 
 const (
 	Trace LogLevel = iota + 1
@@ -55,6 +60,7 @@ func NewPluginWithConfig(config *Config) *Plugin {
 	}
 	return &Plugin{
 		config: config,
+		level:  config.Level,
 	}
 }
 
@@ -88,9 +94,14 @@ func (p *Plugin) CallableByJS() []string {
 		"Warning",
 		"Error",
 		"Fatal",
+		"SetLevel",
 	}
 }
 
+func (p *Plugin) InjectJS() string {
+	return pluginJS
+}
+
 // ---------------- Plugin Methods ----------------
 // Plugin methods are just normal Go methods. You can add as many as you like.
 // The only requirement is that they are exported (start with a capital letter).
@@ -98,7 +109,7 @@ func (p *Plugin) CallableByJS() []string {
 // See https://golang.org/pkg/encoding/json/#Marshal for more information.
 
 func (p *Plugin) write(prefix string, level LogLevel, message string, args ...any) {
-	if level >= p.config.Level {
+	if level >= p.level {
 		if !p.config.DisablePrefix {
 			message = prefix + " " + message
 		}
@@ -134,5 +145,8 @@ func (p *Plugin) Fatal(message string, args ...any) {
 }
 
 func (p *Plugin) SetLevel(newLevel LogLevel) {
+	if newLevel == 0 {
+		newLevel = Debug
+	}
 	p.level = newLevel
 }

v3/plugins/log/plugin.js

@@ -8,7 +8,7 @@
  * @param args {...any} - The arguments for the log message.
  * @returns {Promise<void|Error>}
  */
-export function Trace(input, ...args) {
+function Trace(input, ...args) {
     return wails.Plugin("log", "Trace", input, ...args);
 }
 
@@ -19,7 +19,7 @@ export function Trace(input, ...args) {
  * @returns {Promise<void|Error>}
  */
 
-export function Debug(input, ...args) {
+function Debug(input, ...args) {
     return wails.Plugin("log", "Debug", input, ...args);
 }
 
@@ -29,7 +29,7 @@ export function Debug(input, ...args) {
  * @param args {...any} - The arguments for the log message.
  * @returns {Promise<void|Error>}
  */
-export function Info(input, ...args) {
+function Info(input, ...args) {
     return wails.Plugin("log", "Info", input, ...args);
 }
 
@@ -39,7 +39,7 @@ export function Info(input, ...args) {
  * @param args {...any} - The arguments for the log message.
  * @returns {Promise<void|Error>}
  */
-export function Warning(input, ...args) {
+function Warning(input, ...args) {
     return wails.Plugin("log", "Warning", input, ...args);
 }
 
@@ -49,7 +49,7 @@ export function Warning(input, ...args) {
  * @param args {...any} - The arguments for the log message.
  * @returns {Promise<void|Error>}
  */
-export function Error(input, ...args) {
+function Error(input, ...args) {
     return wails.Plugin("log", "Error", input, ...args);
 }
 
@@ -59,6 +59,40 @@ export function Error(input, ...args) {
  * @param args {...any} - The arguments for the log message.
  * @returns {Promise<void|Error>}
  */
-export function Fatal(input, ...args) {
+function Fatal(input, ...args) {
     return wails.Plugin("log", "Fatal", input, ...args);
 }
+
+/**
+ * SetLevel sets the logging level
+ * @param level {Level} The log level to set
+ * @returns {Promise<void>}
+ */
+function SetLevel(level) {
+    return wails.Plugin("log", "SetLevel", level);
+}
+
+/**
+ * Log Level.
+ * @readonly
+ * @enum {number}
+ */
+let Level = {
+    Trace: 1,
+    Debug: 2,
+    Info: 3,
+    Warning: 4,
+    Error: 5,
+    Fatal: 6,
+};
+
+window.Logger = {
+    Trace,
+    Debug,
+    Info,
+    Warning,
+    Error,
+    Fatal,
+    SetLevel,
+    Level,
+}