[v2] New -debounce flag to configure debounce time of dev server

v2/cmd/wails/internal/commands/dev/dev.go

@@ -93,6 +93,9 @@ func AddSubcommand(app *clir.Cli, w io.Writer) error {
 	forceBuild := false
 	command.BoolFlag("f", "Force build application", &forceBuild)
 
+	debounceMS := 100
+	command.IntFlag("debounce", "The amount of time to wait to trigger a reload on change", &debounceMS)
+
 	command.Action(func() error {
 
 		// Create logger
@@ -249,10 +252,26 @@ func AddSubcommand(app *clir.Cli, w io.Writer) error {
 			}
 		})
 
+		if debounceMS == 100 && projectConfig.DebounceMS != 100 {
+			if projectConfig.DebounceMS == 0 {
+				projectConfig.DebounceMS = 100
+			}
+			debounceMS = projectConfig.DebounceMS
+		}
+
+		if debounceMS != projectConfig.DebounceMS {
+			projectConfig.DebounceMS = debounceMS
+			err := projectConfig.Save()
+			if err != nil {
+				return err
+			}
+		}
+
+		LogGreen("Using reload debounce setting of %d milliseconds", debounceMS)
+
 		// Main Loop
 		quit := false
-		// Use 100ms debounce
-		interval := 100 * time.Millisecond
+		interval := time.Duration(debounceMS) * time.Millisecond
 		timer := time.NewTimer(interval)
 		rebuild := false
 		reload := false

v2/internal/project/project.go

@@ -46,6 +46,9 @@ type Project struct {
 
 	// Fully qualified filename
 	filename string
+
+	// The debounce time for hot-reload of the built-in dev server
+	DebounceMS int `json:"debounceMS"`
 }
 
 func (p *Project) Save() error {

website/docs/guides/application-development.mdx

@@ -161,11 +161,20 @@ The second, if given, will be executed in the `frontend` directory to build the
 
 If these 2 keys aren't given, then Wails does absolutely nothing with the frontend. It is only expecting that `embed.FS`.
 
-## Live Reloading
+## Built in Dev Server
 
-Running `wails dev` will start a file watcher in your project directory. By default, if any file changes, wails checks
-if it was an application file (default: `.go`, configurable with `-e` flag). If it was, then it will rebuild your
-application and relaunch it. If the changed file was in the `assetdir` directory, it will issue a reload.
+Running `wails dev` will start the built in dev server which will start a file watcher in your project directory. By
+default, if any file changes, wails checks if it was an application file (default: `.go`, configurable with `-e` flag).
+If it was, then it will rebuild your application and relaunch it. If the changed file was in the `assetdir` directory,
+it will issue a reload after a short amount of time.
+
+The dev server uses a technique called "debouncing" which means it doesn't reload straight away,
+as there may be multiple files changed in a short amount of time. When a trigger occurs, it waits for a set amount of time
+before issuing a reload. If another trigger happens, it resets to the wait time again. By default this value is `100ms`.
+If this value doesn't work for your project, it can be configured using the `-debounce` flag. If used, this value will
+be saved to your project config and become the default.
+
+## External Dev Server
 
 Some frameworks come with their own live-reloading server, however they will not be able to take advantage of the Wails
 Go bindings. In this scenario, it is best to run a watcher script that rebuilds the project into the build directory, which

website/docs/reference/cli.mdx

@@ -131,7 +131,8 @@ Your system is ready for Wails development!
 |  -loglevel "loglevel"| Loglevel to use - Trace, Debug, Info, Warning, Error | Debug         |
 |  -noreload           | Disable automatic reload when assets change | |
 |  -v                  | Verbosity level (0 - silent, 1 - standard, 2 - verbose)  | 1 |
-|  -wailsjsdir         | The directory to generate the generated Wails JS modules | Value store in `wails.json` |
+|  -wailsjsdir         | The directory to generate the generated Wails JS modules | Value in `wails.json` |
+|  -debounce         | The time to wait for reload after an asset change is detected  | 100 (milliseconds) |
 
 If the `-assetdir` or `-wailsjsdir` flags are provided on the command line, they are saved in `wails.json`, and become
 the defaults for subsequent invocations.

website/docs/reference/project-config.mdx

@@ -14,7 +14,8 @@ The project config resides in the `wails.json` file in the project directory. Th
 	"frontend:build": "[The command to build the assets, run in the frontend directory - often `npm run build`]",
     "wailsjsdir": "[Relative path to the directory that the auto-generated JS modules will be created]",
 	"version": "[Project config version]",
-	"outputfilename": "[The name of the binary]"
+	"outputfilename": "[The name of the binary]",
+	"debounceMS": 100, // The default time the dev server waits to reload when it detects a vhange in assets
 }
 ```