func Example() {
runtime.LockOSThread()
gtk.Init(nil)
webView := webkit2.NewWebView()
defer webView.Destroy()
webView.Connect("load-failed", func() {
fmt.Println("Load failed.")
})
webView.Connect("load-changed", func(_ *glib.Object, i int) {
loadEvent := webkit2.LoadEvent(i)
switch loadEvent {
case webkit2.LoadFinished:
fmt.Println("Load finished.")
fmt.Printf("Title: %q\n", webView.Title())
fmt.Printf("URI: %s\n", webView.URI())
webView.RunJavaScript("window.location.hostname", func(val *gojs.Value, err error) {
if err != nil {
fmt.Println("JavaScript error.")
} else {
fmt.Printf("Hostname (from JavaScript): %q\n", val)
}
gtk.MainQuit()
})
}
})
glib.IdleAdd(func() bool {
webView.LoadURI("https://www.google.com/")
return false
})
gtk.Main()
// output:
// Load finished.
// Title: "Google"
// URI: https://www.google.com/
// Hostname (from JavaScript): "www.google.com"
}
func main() {
flag.Usage = func() {
fmt.Fprintln(os.Stderr)
fmt.Fprintf(os.Stderr, "webkit-eval-js evaluates a JavaScript expression in the context of a web page\n")
fmt.Fprintf(os.Stderr, "running in a headless instance of the WebKit browser.\n\n")
fmt.Fprintf(os.Stderr, "Usage:\n\n")
fmt.Fprintf(os.Stderr, "\twebkit-eval-js url script-file\n\n")
fmt.Fprintf(os.Stderr, "url is the web page to execute the script in, and script-file is a local file\n")
fmt.Fprintf(os.Stderr, "with the JavaScript you want to evaluate. The result is printed to stdout as JSON.\n\n")
fmt.Fprintln(os.Stderr)
fmt.Fprintf(os.Stderr, "Example usage:\n\n")
fmt.Fprintf(os.Stderr, "\tTo return the value of `document.title` on https://google.com:\n")
fmt.Fprintf(os.Stderr, "\t $ echo document.title | webkit-eval-js https://google.com /dev/stdin\n")
fmt.Fprintf(os.Stderr, "\tPrints:\n")
fmt.Fprintf(os.Stderr, "\t \"Google\"\n\n")
fmt.Fprintf(os.Stderr, "Notes:\n\n")
fmt.Fprintf(os.Stderr, "\tBecause a headless WebKit instance is used, your $DISPLAY must be set. Use\n")
fmt.Fprintf(os.Stderr, "\tXvfb if you are running on a machine without an existing X server. See\n")
fmt.Fprintf(os.Stderr, "\thttps://sourcegraph.com/github.com/sourcegraph/go-webkit2/readme for more info.\n")
fmt.Fprintln(os.Stderr)
os.Exit(1)
}
flag.Parse()
if flag.NArg() != 2 {
flag.Usage()
os.Exit(1)
}
log := log.New(os.Stderr, "", 0)
pageURL := flag.Arg(0)
scriptFile := flag.Arg(1)
if _, err := url.Parse(pageURL); err != nil {
log.Fatalf("Failed to parse URL %q: %s", pageURL, err)
}
script, err := ioutil.ReadFile(scriptFile)
if err != nil {
log.Fatalf("Failed to open script file %q: %s", scriptFile, err)
}
runtime.LockOSThread()
gtk.Init(nil)
webView := webkit2.NewWebView()
defer webView.Destroy()
webView.Connect("load-failed", func() {
fmt.Println("Load failed.")
})
webView.Connect("load-changed", func(_ *glib.Object, loadEvent webkit2.LoadEvent) {
switch loadEvent {
case webkit2.LoadFinished:
webView.RunJavaScript(string(script), func(val *gojs.Value, err error) {
if err != nil {
log.Fatalf("JavaScript error: %s", err)
} else {
json, err := val.JSON()
if err != nil {
log.Fatal("JavaScript serialization error: %s", err)
}
fmt.Println(string(json))
}
gtk.MainQuit()
})
}
})
glib.IdleAdd(func() bool {
webView.LoadURI(pageURL)
return false
})
gtk.Main()
}