WebLoop
Scriptable, headless WebKit with a Go API. Like PhantomJS, but for Go. Render static HTML versions of dynamic JavaScript applications, automate browsing, run arbitrary JavaScript in a browser window context, etc., all from Go or the command line.
Requirements
- Go >= 1.2rc1 (due to #3250)
- WebKitGTK+ >= 2.0.0
- go-webkit2
For instructions on installing these dependencies, see the go-webkit2
README.
To install WebLoop, run: go get github.com/sourcegraph/webloop/...
Usage
Static HTML rendering reverse proxy
The included command static-reverse-proxy proxies a dynamic JavaScript application and serves an equivalent statically rendered HTML website to clients. Run it with:
$ go install github.com/sourcegraph/webloop/...
$ static-reverse-proxy
For example, to proxy a dynamic application at http://example.com and serve an
equivalent statically rendered HTML website on http://localhost:13000, run:
$ static-reverse-proxy -target=http://example.com -http=:13000
Run with -h to see more information.
Rendering static HTML from a dynamic, single-page AngularJS app
StaticRenderer is an HTTP handler that serves a static HTML version of a
dynamic web application. Use it like:
staticHandler := &webloop.StaticRenderer{
TargetBaseURL: "http://dynamic-app.example.com",
WaitTimeout: time.Second * 3,
ReturnUnfinishedPages: true
}
http.Handle("/", staticHandler)
See the examples/angular-static-seo/ directory for example code. Run the included binary with:
$ go run examples/angular-static-seo/server.go
Instructions will be printed for accessing the 2 local demo HTTP servers. Run
with -h to see more information.
Operating a headless WebKit and running arbitrary JavaScript in the page
package webloop_test
import (
"fmt"
"os"
"runtime"
"github.com/gotk3/gotk3/gtk"
"github.com/sourcegraph/webloop"
)
func Example() {
gtk.Init(nil)
go func() {
runtime.LockOSThread()
gtk.Main()
}()
ctx := webloop.New()
view := ctx.NewView()
defer view.Close()
view.Open("http://google.com")
err := view.Wait()
if err != nil {
fmt.Fprintf(os.Stderr, "Failed to load URL: %s", err)
os.Exit(1)
}
res, err := view.EvaluateJavaScript("document.title")
if err != nil {
fmt.Fprintf(os.Stderr, "Failed to run JavaScript: %s", err)
os.Exit(1)
}
fmt.Printf("JavaScript returned: %q\n", res)
// output:
// JavaScript returned: "Google"
}
See webloop_test.go for more examples.
TODO
- Set up CI testing. This
is difficult because all of the popular CI services run older versions of
Ubuntu that make it difficult to install WebKitGTK+ >= 2.0.0. - Add the ability for JavaScript code to send messages to WebLoop, similar to
[PhantomJS's callPhantom]
(https://github.com/ariya/phantomjs/wiki/API-Reference-WebPage#oncallback)
mechanism.
Users
- WebLoop is used to render static HTML pages on Sourcegraph for search engine crawlers
Contributors
See the AUTHORS file for a list of contributors.
Submit contributions via GitHub pull request. Patches should include tests and
should pass golint.