feat: add bind_opt and bind_opt_with_ctx (#30)

examples/project-structure/src/api.v

@@ -5,7 +5,7 @@ fn (mut app App) bind(w &Webview) {
  // The first string argument is the functions name in the JS frontend.
  // Use JS's `camelCase` convention or distinct identifiers if you prefer it.
  w.bind('get_settings', app.get_settings)
- w.bind_ctx('toggle_setting', toggle, app) // Alternatively use the ctx ptr to pass a struct.
+ w.bind_with_ctx('toggle_setting', toggle, app) // Alternatively use the ctx ptr to pass a struct.
  w.bind('login', login)
  w.bind('fetch_news', fetch_news)
 }
@@ -17,7 +17,7 @@ fn (app App) get_settings(_ &Event) Settings {
 }
 
 // Returns a value when it's called from JS.
-// This examples uses bind_ctx, adding the App struct as context argument.
+// This examples uses `bind_with_ctx` to add the App struct as context argument.
 fn toggle(_ &Event, mut app App) bool {
  app.settings.toggle = !app.settings.toggle
  dump(app.settings.toggle)

examples/v-js-interop-app/main.v

@@ -26,7 +26,7 @@ fn (app App) get_settings(_ &Event) Settings {
 }
 
 // Returns a value when it's called from JS.
-// This examples uses bind_ctx, adding the App struct as context argument.
+// This examples uses `bind_with_ctx` to add the App struct as context argument.
 fn toggle(_ &Event, mut app App) bool {
  app.settings.toggle = !app.settings.toggle
  dump(app.settings.toggle)
@@ -78,7 +78,7 @@ fn main() {
  // The first string argument is the functions name in the JS frontend.
  // Use JS's `camelCase` convention or distinct identifiers if you prefer it.
  w.bind('get_settings', app.get_settings)
- w.bind_ctx('toggle_setting', toggle, &app) // Alternatively use the ctx ptr to pass a struct.
+ w.bind_with_ctx('toggle_setting', toggle, &app) // Alternatively use the ctx ptr to pass a struct.
  w.bind('login', login)
  w.bind('fetch_news', fetch_news)
 

src/lib.v

@@ -31,16 +31,6 @@ pub struct CreateOptions {
  window voidptr
 }
 
-[params]
-pub struct ReturnParams {
- kind ReturnKind
-}
-
-pub enum ReturnKind {
- value
- error
-}
-
 // A Hint that is passed to the Webview 'set_size' method to determine the window sizing behavior.
 pub enum Hint {
  // Width and height are default size.
@@ -150,28 +140,71 @@ pub fn (w &Webview) eval(code string) {
  C.webview_eval(w, &char(code.str))
 }
 
-// bind binds a callback so that it will appear under the given name as a
-// global JavaScript function. Internally it uses webview_init().
-// The callback receives an `&Event` pointer.
+// bind binds a V callback to a global JavaScript function that will appear under the given name.
+// The callback receives an `&Event` argument. Internally it uses webview_init().
 pub fn (w &Webview) bind[T](name string, func fn (&Event) T) {
  C.webview_bind(w, &char(name.str), fn [w, func] [T](event_id &char, args &char, ctx voidptr) {
  e := unsafe { &Event{w, event_id, args} }
  spawn fn [func] [T](e &Event) {
  result := func(e)
- e.@return(result)
+ e.@return(result, .value)
+ }(e.async())
+ }, 0)
+}
+
+// bind_opt binds a V callback with a result return type to a global JavaScript function that will
+// appear under the given name. The callback receives an `&Event` argument. The callback can return an
+// error to the calling JavaScript function. Internally it uses webview_init().
+pub fn (w &Webview) bind_opt[T](name string, func fn (&Event) !T) {
+ C.webview_bind(w, &char(name.str), fn [w, func] [T](event_id &char, args &char, ctx voidptr) {
+ e := unsafe { &Event{w, event_id, args} }
+ spawn fn [func] [T](e &Event) {
+ if result := func(e) {
+ e.@return(result, .value)
+ } else {
+ e.@return(err.str(), .error)
+ }
  }(e.async())
  }, 0)
 }
 
-// bind_ctx binds a callback so that it will appear under the given name as a
-// global JavaScript function. Internally it uses webview_init().
-// The callback receives an `7Event` pointer and a user-provided ctx pointer.
+// bind_ctx binds a V callback to a global JavaScript function that will appear under the given name.
+// The callback receives an `&Event` and a user-provided ctx pointer argument.
+[deprecated: 'will be removed with v0.7; use `bind_with_ctx` instead.']
 pub fn (w &Webview) bind_ctx[T](name string, func fn (e &Event, ctx voidptr) T, ctx voidptr) {
  C.webview_bind(w, &char(name.str), fn [w, func] [T](event_id &char, args &char, ctx voidptr) {
  e := unsafe { &Event{w, event_id, args} }
  spawn fn [func, ctx] [T](e &Event) {
  result := func(e, ctx)
- e.@return(result)
+ e.@return(result, .value)
+ }(e.async())
+ }, ctx)
+}
+
+// bind_with_ctx binds a V callback to a global JavaScript function that will appear under the given name.
+// The callback receives an `&Event` and a user-provided ctx pointer argument.
+pub fn (w &Webview) bind_with_ctx[T](name string, func fn (e &Event, ctx voidptr) T, ctx voidptr) {
+ C.webview_bind(w, &char(name.str), fn [w, func] [T](event_id &char, args &char, ctx voidptr) {
+ e := unsafe { &Event{w, event_id, args} }
+ spawn fn [func, ctx] [T](e &Event) {
+ result := func(e, ctx)
+ e.@return(result, .value)
+ }(e.async())
+ }, ctx)
+}
+
+// bind_opt_with_ctx binds a V callback with a result return type to a global JavaScript function that will
+// appear under the given name. The callback receives an `&Event` and a user-provided ctx pointer argument.
+// The callback can return an error to the calling JavaScript function. Internally it uses webview_init().
+pub fn (w &Webview) bind_opt_with_ctx[T](name string, func fn (e &Event, ctx voidptr) T, ctx voidptr) {
+ C.webview_bind(w, &char(name.str), fn [w, func] [T](event_id &char, args &char, ctx voidptr) {
+ e := unsafe { &Event{w, event_id, args} }
+ spawn fn [func, ctx] [T](e &Event) {
+ if result := func(e, ctx) {
+ e.@return(result, .value)
+ } else {
+ e.@return(err, .error)
+ }
  }(e.async())
  }, ctx)
 }
@@ -250,7 +283,7 @@ pub fn (e &Event) int_opt(idx usize) ?int {
  return e.args_json[int]() or { return none }[int(idx)] or { return none }
 }
 
-// bool_opt decodes and return the argument with the given index as boolean option.
+// bool_opt parses and return the argument with the given index as boolean option.
 [deprecated: 'will be removed with v0.7; use `get_arg[T](idx int) !T` instead. E.g: `e.get_arg[bool](0)!`']
 pub fn (e &Event) bool_opt(idx usize) ?bool {
  return e.args_json[bool]() or { return none }[int(idx)] or { return none }

src/utils.v

@@ -2,8 +2,13 @@ module webview
 
 import json
 
+enum ReturnKind {
+ value
+ error
+}
+
 // copy_char copies a C style string. The functions main use case is passing an `event_id &char`
-// to another thread. It helps to keep the event id available when executing `@return`
+// to another thread. It helps to keep the event id available when executing `@retrun`
 // from the spawned thread. Without copying the `event_id` might get obscured during garbage
 // collection and returning data to a calling JS function becomes error prone.
 fn copy_char(s &char) &char {
@@ -14,11 +19,11 @@ fn copy_char(s &char) &char {
 // be provided to allow the internal RPC engine to match the request and response.
 // If the status is zero - the result is expected to be a valid JSON value.
 // If the status is not zero - the result is an error JSON object.
-fn (e &Event) @return[T](result T, return_params ReturnParams) {
+fn (e &Event) @return[T](result T, kind ReturnKind) {
  $if result is voidptr {
- C.webview_return(e.instance, e.event_id, 0, &char(''.str))
+ C.webview_return(e.instance, e.event_id, int(kind), &char(''.str))
  } $else {
- C.webview_return(e.instance, e.event_id, 0, &char(json.encode(result).str))
+ C.webview_return(e.instance, e.event_id, int(kind), &char(json.encode(result).str))
  }
 }
 

tests/v_fn_call_test.v

@@ -1,5 +1,6 @@
 import webview
 import time
+import os
 
 struct Person {
  name string
@@ -149,3 +150,41 @@ fn test_return_value_from_threaded_task_to_js() {
  w.set_html(gen_html(@FN, script))
  w.run()
 }
+
+fn test_fn_call_with_error() {
+ w := webview.create(debug: true)
+ w.set_size(600, 400, .@none)
+ w.bind_opt('v_fn_with_custom_error', fn (e &webview.Event) !int {
+ return error('my error')
+ })
+ w.bind[voidptr]('assert_custom_error', fn (e &webview.Event) {
+ assert e.get_arg[string](0) or { '' } == 'my error'
+ })
+ w.bind_opt('v_fn_with_error_propagation', fn (e &webview.Event) !string {
+ return os.existing_path('my_inexistent_path/file.v')!
+ })
+ w.bind[voidptr]('assert_error_propagation', fn (e &webview.Event) {
+ assert e.get_arg[string](0) or { '' } == 'path does not exist'
+ })
+ w.bind[voidptr]('exit', fn [w] (_ &webview.Event) {
+ w.terminate()
+ })
+ script := '
+ setTimeout(async () => {
+ try {
+ await window.v_fn_with_custom_error();
+ } catch (err) {
+ console.log(err);
+ await window.assert_custom_error(err);
+ }
+ try {
+ await window.v_fn_with_error_propagation();
+ } catch (err) {
+ console.log(err);
+ await window.assert_error_propagation(err);
+ await window.exit();
+ }
+ }, 500)'
+ w.set_html(gen_html(@FN, script))
+ w.run()
+}