Simple logging plugin

v3/examples/plugins/main.go

@@ -5,7 +5,8 @@ import (
 	"github.com/wailsapp/wails/v3/pkg/application"
 	"github.com/wailsapp/wails/v3/plugins/browser"
 	"github.com/wailsapp/wails/v3/plugins/kvstore"
-	"log"
+	"github.com/wailsapp/wails/v3/plugins/log"
+	"os"
 	"plugin_demo/plugins/hashes"
 	//"plugin_demo/plugins/hashes"
 )
@@ -24,6 +25,7 @@ func main() {
 		Plugins: map[string]application.Plugin{
 			"hashes":  hashes.NewPlugin(),
 			"browser": browser.NewPlugin(),
+			"log":     log.NewPlugin(),
 			"kvstore": kvstore.NewPlugin(&kvstore.Config{
 				Filename: "store.json",
 				AutoSave: true,
@@ -40,6 +42,7 @@ func main() {
 	err := app.Run()
 
 	if err != nil {
-		log.Fatal(err.Error())
+		println(err.Error())
+		os.Exit(1)
 	}
 }

v3/plugins/log/README.md

@@ -0,0 +1,38 @@
+# log Plugin
+
+This example plugin provides a way to generate hashes of strings.
+
+## Installation
+
+Add the plugin to the `Plugins` option in the Applications options:
+
+```go
+    Plugins: map[string]application.Plugin{
+        "log": log.NewPlugin(),
+    },
+```
+
+## Usage
+
+You can then call the methods from the frontend:
+
+```js
+    wails.Plugin("log","All","hello world").then((result) => console.log(result))
+```
+
+This method returns a struct with the following fields:
+
+```typescript
+    interface Hashes {
+        MD5: string;
+        SHA1: string;
+        SHA256: string;
+    }
+```
+
+A TypeScript definition file is provided for this interface.
+
+## Support
+
+If you find a bug in this plugin, please raise a ticket [here](https://github.com/plugin/repository). 
+Please do not contact the Wails team for support.

v3/plugins/log/plugin.go

@@ -0,0 +1,138 @@
+package log
+
+import (
+	"fmt"
+	"github.com/wailsapp/wails/v3/pkg/application"
+	"io"
+	"os"
+)
+
+// ---------------- 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
+
+const (
+	Trace LogLevel = iota + 1
+	Debug
+	Info
+	Warning
+	Error
+	Fatal
+)
+
+type Config struct {
+	// Where the logs are written to. Defaults to os.Stderr
+	// If you want to write to a file, use os.OpenFile()
+	// e.g. os.OpenFile("mylog.log", os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
+	// Closes the writer when the app shuts down
+	Writer io.WriteCloser
+
+	// The initial log level. Defaults to Debug
+	Level LogLevel
+
+	// Disables the log level prefixes
+	DisablePrefix bool
+
+	// Handles errors that occur when writing to the log
+	ErrorHandler func(err error)
+}
+
+type Plugin struct {
+	config *Config
+	app    *application.App
+	level  LogLevel
+}
+
+func NewPluginWithConfig(config *Config) *Plugin {
+	if config.Level == 0 {
+		config.Level = Debug
+	}
+	if config.Writer == nil {
+		config.Writer = os.Stderr
+	}
+	return &Plugin{
+		config: config,
+	}
+}
+
+func NewPlugin() *Plugin {
+	return NewPluginWithConfig(&Config{})
+}
+
+// Shutdown is called when the app is shutting down
+// You can use this to clean up any resources you have allocated
+func (p *Plugin) Shutdown() {
+	p.config.Writer.Close()
+}
+
+// Name returns the name of the plugin.
+// You should use the go module format e.g. github.com/myuser/myplugin
+func (p *Plugin) Name() string {
+	return "github.com/wailsapp/wails/v3/plugins/log"
+}
+
+func (p *Plugin) Init(app *application.App) error {
+	p.app = app
+	return nil
+}
+
+// CallableByJS returns a list of methods that can be called from the frontend
+func (p *Plugin) CallableByJS() []string {
+	return []string{
+		"Trace",
+		"Debug",
+		"Info",
+		"Warning",
+		"Error",
+		"Fatal",
+	}
+}
+
+// ---------------- 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).
+// You can also return any type that is JSON serializable.
+// 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 !p.config.DisablePrefix {
+			message = prefix + " " + message
+		}
+		_, err := fmt.Fprintln(p.config.Writer, fmt.Sprintf(message, args...))
+		if err != nil && p.config.ErrorHandler != nil {
+			p.config.ErrorHandler(err)
+		}
+	}
+}
+
+func (p *Plugin) Trace(message string, args ...any) {
+	p.write("[Trace]", Trace, message, args...)
+}
+
+func (p *Plugin) Debug(message string, args ...any) {
+	p.write("[Debug]", Debug, message, args...)
+}
+
+func (p *Plugin) Info(message string, args ...any) {
+	p.write("[Info]", Info, message, args...)
+}
+
+func (p *Plugin) Warning(message string, args ...any) {
+	p.write("[Warning]", Warning, message, args...)
+}
+
+func (p *Plugin) Error(message string, args ...any) {
+	p.write("[Error]", Error, message, args...)
+}
+
+func (p *Plugin) Fatal(message string, args ...any) {
+	p.write("[FATAL]", Fatal, message, args...)
+}
+
+func (p *Plugin) SetLevel(newLevel LogLevel) {
+	p.level = newLevel
+}

v3/plugins/log/plugin.js

@@ -0,0 +1,64 @@
+// plugin.js
+// This file should contain helper functions for the that can be used by the frontend.
+// Below are examples of how to use JSDoc to define the Hashes struct and the exported functions.
+
+/**
+ * Log at the Trace level.
+ * @param input {string} - The message in printf format.
+ * @param args {...any} - The arguments for the log message.
+ * @returns {Promise<void|Error>}
+ */
+export function Trace(input, ...args) {
+    return wails.Plugin("log", "Trace", input, ...args);
+}
+
+/**
+ * Log at the Debug level.
+ * @param input {string} - The message in printf format.
+ * @param args {...any} - The arguments for the log message.
+ * @returns {Promise<void|Error>}
+ */
+
+export function Debug(input, ...args) {
+    return wails.Plugin("log", "Debug", input, ...args);
+}
+
+/**
+ * Log at the Info level.
+ * @param input {string} - The message in printf format.
+ * @param args {...any} - The arguments for the log message.
+ * @returns {Promise<void|Error>}
+ */
+export function Info(input, ...args) {
+    return wails.Plugin("log", "Info", input, ...args);
+}
+
+/**
+ * Log at the Warning level.
+ * @param input {string} - The message in printf format.
+ * @param args {...any} - The arguments for the log message.
+ * @returns {Promise<void|Error>}
+ */
+export function Warning(input, ...args) {
+    return wails.Plugin("log", "Warning", input, ...args);
+}
+
+/**
+ * Log at the Error level.
+ * @param input {string} - The message in printf format.
+ * @param args {...any} - The arguments for the log message.
+ * @returns {Promise<void|Error>}
+ */
+export function Error(input, ...args) {
+    return wails.Plugin("log", "Error", input, ...args);
+}
+
+/**
+ * Log at the Fatal level.
+ * @param input {string} - The message in printf format.
+ * @param args {...any} - The arguments for the log message.
+ * @returns {Promise<void|Error>}
+ */
+export function Fatal(input, ...args) {
+    return wails.Plugin("log", "Fatal", input, ...args);
+}

v3/plugins/log/plugin.toml

@@ -0,0 +1,11 @@
+# This is the plugin definition file for the "log" plugin.
+
+Name = "log"
+Description = "A basic logger"
+Author = "Lea Anthony"
+Version = "v1.0.0"
+Website = "https://wails.io"
+Repository = "https://github.com/wailsapp/wails/v3/plugins/log"
+License = "MIT"
+
+