/
example_test.go
750 lines (648 loc) · 17.6 KB
/
example_test.go
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package chromedp_test
import (
"bytes"
"context"
"fmt"
"io"
"log"
"net/http"
"net/http/httptest"
"os"
"path/filepath"
"strings"
"time"
"github.com/chromedp/chromedp"
"github.com/chromedp/chromedp/device"
"github.com/chromedp/cdproto/cdp"
"github.com/chromedp/cdproto/dom"
"github.com/chromedp/cdproto/page"
"github.com/chromedp/cdproto/runtime"
"github.com/chromedp/cdproto/target"
)
func writeHTML(content string) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "text/html")
io.WriteString(w, strings.TrimSpace(content))
})
}
func ExampleTitle() {
ctx, cancel := chromedp.NewContext(context.Background())
defer cancel()
ts := httptest.NewServer(writeHTML(`
<head>
<title>fancy website title</title>
</head>
<body>
<div id="content"></div>
</body>
`))
defer ts.Close()
var title string
if err := chromedp.Run(ctx,
chromedp.Navigate(ts.URL),
chromedp.Title(&title),
); err != nil {
log.Fatal(err)
}
fmt.Println(title)
// Output:
// fancy website title
}
func ExampleRunResponse() {
ctx, cancel := chromedp.NewContext(context.Background())
defer cancel()
// This server simply shows the URL path as the page title, and contains
// a link that points to /foo.
ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "text/html")
fmt.Fprintf(w, `
<head><title>%s</title></head>
<body><a id="foo" href="/foo">foo</a></body>
`, r.URL.Path)
}))
defer ts.Close()
// The Navigate action already waits until a page loads, so Title runs
// once the page is ready.
var firstTitle string
if err := chromedp.Run(ctx,
chromedp.Navigate(ts.URL),
chromedp.Title(&firstTitle),
); err != nil {
log.Fatal(err)
}
fmt.Println("first title:", firstTitle)
// However, actions like Click don't always trigger a page navigation,
// so they don't wait for a page load directly. Wrapping them with
// RunResponse does that waiting, and also obtains the HTTP response.
resp, err := chromedp.RunResponse(ctx, chromedp.Click("#foo", chromedp.ByID))
if err != nil {
log.Fatal(err)
}
fmt.Println("second status code:", resp.Status)
// Grabbing the title again should work, as the page has finished
// loading once more.
var secondTitle string
if err := chromedp.Run(ctx, chromedp.Title(&secondTitle)); err != nil {
log.Fatal(err)
}
fmt.Println("second title:", secondTitle)
// Finally, it's always possible to wrap Navigate with RunResponse, if
// one wants the response information for that case too.
resp, err = chromedp.RunResponse(ctx, chromedp.Navigate(ts.URL+"/bar"))
if err != nil {
log.Fatal(err)
}
fmt.Println("third status code:", resp.Status)
// Output:
// first title: /
// second status code: 200
// second title: /foo
// third status code: 200
}
func ExampleExecAllocator() {
dir, err := os.MkdirTemp("", "chromedp-example")
if err != nil {
log.Fatal(err)
}
defer os.RemoveAll(dir)
opts := append(chromedp.DefaultExecAllocatorOptions[:],
chromedp.DisableGPU,
chromedp.UserDataDir(dir),
)
allocCtx, cancel := chromedp.NewExecAllocator(context.Background(), opts...)
defer cancel()
// also set up a custom logger
taskCtx, cancel := chromedp.NewContext(allocCtx, chromedp.WithLogf(log.Printf))
defer cancel()
// ensure that the browser process is started
if err := chromedp.Run(taskCtx); err != nil {
log.Fatal(err)
}
path := filepath.Join(dir, "DevToolsActivePort")
bs, err := os.ReadFile(path)
if err != nil {
log.Fatal(err)
}
lines := bytes.Split(bs, []byte("\n"))
fmt.Printf("DevToolsActivePort has %d lines\n", len(lines))
// Output:
// DevToolsActivePort has 2 lines
}
func ExampleNewContext_reuseBrowser() {
ts := httptest.NewServer(writeHTML(`
<body>
<script>
// Show the current cookies.
var p = document.createElement("p")
p.innerText = document.cookie
p.setAttribute("id", "cookies")
document.body.appendChild(p)
// Override the cookies.
document.cookie = "foo=bar"
</script>
</body>
`))
defer ts.Close()
// create a new browser
ctx, cancel := chromedp.NewContext(context.Background())
defer cancel()
// start the browser without a timeout
if err := chromedp.Run(ctx); err != nil {
log.Fatal(err)
}
for i := 0; i < 2; i++ {
func() {
ctx, cancel := context.WithTimeout(ctx, time.Second)
defer cancel()
ctx, cancel = chromedp.NewContext(ctx)
defer cancel()
var cookies string
if err := chromedp.Run(ctx,
chromedp.Navigate(ts.URL),
chromedp.Text("#cookies", &cookies),
); err != nil {
log.Fatal(err)
}
fmt.Printf("Cookies at i=%d: %q\n", i, cookies)
}()
}
// Output:
// Cookies at i=0: ""
// Cookies at i=1: "foo=bar"
}
func ExampleNewContext_manyTabs() {
// new browser, first tab
ctx1, cancel := chromedp.NewContext(context.Background())
defer cancel()
// ensure the first tab is created
if err := chromedp.Run(ctx1); err != nil {
log.Fatal(err)
}
// same browser, second tab
ctx2, _ := chromedp.NewContext(ctx1)
// ensure the second tab is created
if err := chromedp.Run(ctx2); err != nil {
log.Fatal(err)
}
c1 := chromedp.FromContext(ctx1)
c2 := chromedp.FromContext(ctx2)
fmt.Printf("Same browser: %t\n", c1.Browser == c2.Browser)
fmt.Printf("Same tab: %t\n", c1.Target == c2.Target)
// Output:
// Same browser: true
// Same tab: false
}
func ExampleListenTarget_consoleLog() {
ctx, cancel := chromedp.NewContext(context.Background())
defer cancel()
ts := httptest.NewServer(writeHTML(`
<body>
<script>
console.log("hello js world")
console.warn("scary warning", 123)
null.throwsException
</script>
</body>
`))
defer ts.Close()
gotException := make(chan bool, 1)
chromedp.ListenTarget(ctx, func(ev interface{}) {
switch ev := ev.(type) {
case *runtime.EventConsoleAPICalled:
fmt.Printf("* console.%s call:\n", ev.Type)
for _, arg := range ev.Args {
fmt.Printf("%s - %s\n", arg.Type, arg.Value)
}
case *runtime.EventExceptionThrown:
// Since ts.URL uses a random port, replace it.
s := ev.ExceptionDetails.Error()
s = strings.ReplaceAll(s, ts.URL, "<server>")
// V8 has changed the error messages for property access on null/undefined in version 9.3.310.
// see: https://chromium.googlesource.com/v8/v8/+/c0fd89c3c089e888c4f4e8582e56db7066fa779b
// https://github.com/chromium/chromium/commit/1735cbf94c98c70ff7554a1e9e01bb9a4f91beb6
// The message is normalized to make it compatible with the versions before this change.
s = strings.ReplaceAll(s, "Cannot read property 'throwsException' of null", "Cannot read properties of null (reading 'throwsException')")
fmt.Printf("* %s\n", s)
gotException <- true
}
})
if err := chromedp.Run(ctx, chromedp.Navigate(ts.URL)); err != nil {
log.Fatal(err)
}
<-gotException
// Output:
// * console.log call:
// string - "hello js world"
// * console.warning call:
// string - "scary warning"
// number - 123
// * exception "Uncaught" (4:6): TypeError: Cannot read properties of null (reading 'throwsException')
// at <server>/:5:7
}
func ExampleWaitNewTarget() {
ctx, cancel := chromedp.NewContext(context.Background())
defer cancel()
mux := http.NewServeMux()
mux.Handle("/first", writeHTML(`
<input id='newtab' type='button' value='open' onclick='window.open("/second", "_blank");'/>
`))
mux.Handle("/second", writeHTML(``))
ts := httptest.NewServer(mux)
defer ts.Close()
// Grab the first spawned tab that isn't blank.
ch := chromedp.WaitNewTarget(ctx, func(info *target.Info) bool {
return info.URL != ""
})
if err := chromedp.Run(ctx,
chromedp.Navigate(ts.URL+"/first"),
chromedp.Click("#newtab", chromedp.ByID),
); err != nil {
log.Fatal(err)
}
newCtx, cancel := chromedp.NewContext(ctx, chromedp.WithTargetID(<-ch))
defer cancel()
var urlstr string
if err := chromedp.Run(newCtx, chromedp.Location(&urlstr)); err != nil {
log.Fatal(err)
}
fmt.Println("new tab's path:", strings.TrimPrefix(urlstr, ts.URL))
// Output:
// new tab's path: /second
}
func ExampleListenTarget_acceptAlert() {
ctx, cancel := chromedp.NewContext(context.Background())
defer cancel()
mux := http.NewServeMux()
mux.Handle("/second", writeHTML(``))
ts := httptest.NewServer(writeHTML(`
<input id='alert' type='button' value='alert' onclick='alert("alert text");'/>
`))
defer ts.Close()
chromedp.ListenTarget(ctx, func(ev interface{}) {
if ev, ok := ev.(*page.EventJavascriptDialogOpening); ok {
fmt.Println("closing alert:", ev.Message)
go func() {
if err := chromedp.Run(ctx,
page.HandleJavaScriptDialog(true),
); err != nil {
log.Fatal(err)
}
}()
}
})
if err := chromedp.Run(ctx,
chromedp.Navigate(ts.URL),
chromedp.Click("#alert", chromedp.ByID),
); err != nil {
log.Fatal(err)
}
// Output:
// closing alert: alert text
}
func Example_retrieveHTML() {
ctx, cancel := chromedp.NewContext(context.Background())
defer cancel()
ts := httptest.NewServer(writeHTML(`
<body>
<p id="content" onclick="changeText()">Original content.</p>
<script>
function changeText() {
document.getElementById("content").textContent = "New content!"
}
</script>
</body>
`))
defer ts.Close()
var outerBefore, outerAfter string
if err := chromedp.Run(ctx,
chromedp.Navigate(ts.URL),
chromedp.OuterHTML("#content", &outerBefore, chromedp.ByQuery),
chromedp.Click("#content", chromedp.ByQuery),
chromedp.OuterHTML("#content", &outerAfter, chromedp.ByQuery),
); err != nil {
log.Fatal(err)
}
fmt.Println("OuterHTML before clicking:")
fmt.Println(outerBefore)
fmt.Println("OuterHTML after clicking:")
fmt.Println(outerAfter)
// Output:
// OuterHTML before clicking:
// <p id="content" onclick="changeText()">Original content.</p>
// OuterHTML after clicking:
// <p id="content" onclick="changeText()">New content!</p>
}
func ExampleEmulate() {
ctx, cancel := chromedp.NewContext(context.Background())
defer cancel()
var buf []byte
if err := chromedp.Run(ctx,
chromedp.Emulate(device.IPhone7),
chromedp.Navigate(`https://duckduckgo.com/`),
chromedp.SendKeys(`input[name=q]`, "what's my user agent?\n"),
chromedp.WaitVisible(`#zci-answer`, chromedp.ByID),
chromedp.CaptureScreenshot(&buf),
); err != nil {
log.Fatal(err)
}
if err := os.WriteFile("iphone7-ua.png", buf, 0o644); err != nil {
log.Fatal(err)
}
// Output:
}
func ExamplePrintToPDF() {
ctx, cancel := chromedp.NewContext(context.Background())
defer cancel()
var buf []byte
if err := chromedp.Run(ctx,
chromedp.Navigate(`https://pkg.go.dev/github.com/chromedp/chromedp`),
chromedp.ActionFunc(func(ctx context.Context) error {
var err error
buf, _, err = page.PrintToPDF().
WithDisplayHeaderFooter(false).
WithLandscape(true).
Do(ctx)
return err
}),
); err != nil {
log.Fatal(err)
}
if err := os.WriteFile("page.pdf", buf, 0o644); err != nil {
log.Fatal(err)
}
// Output:
}
func ExampleByJSPath() {
ctx, cancel := chromedp.NewContext(context.Background())
defer cancel()
ts := httptest.NewServer(writeHTML(`
<body>
<div id="content">cool content</div>
</body>
`))
defer ts.Close()
var ids []cdp.NodeID
var html string
if err := chromedp.Run(ctx,
chromedp.Navigate(ts.URL),
chromedp.NodeIDs(`document`, &ids, chromedp.ByJSPath),
chromedp.ActionFunc(func(ctx context.Context) error {
var err error
html, err = dom.GetOuterHTML().WithNodeID(ids[0]).Do(ctx)
return err
}),
); err != nil {
log.Fatal(err)
}
fmt.Println("Outer HTML:")
fmt.Println(html)
// Output:
// Outer HTML:
// <html><head></head><body>
// <div id="content">cool content</div>
// </body></html>
}
func ExampleFromNode() {
ctx, cancel := chromedp.NewContext(context.Background())
defer cancel()
ts := httptest.NewServer(writeHTML(`
<body>
<p class="content">outer content</p>
<div id="section"><p class="content">inner content</p></div>
</body>
`))
defer ts.Close()
var nodes []*cdp.Node
if err := chromedp.Run(ctx,
chromedp.Navigate(ts.URL),
chromedp.Nodes("#section", &nodes, chromedp.ByQuery),
); err != nil {
log.Fatal(err)
}
sectionNode := nodes[0]
var queryRoot, queryFromNode, queryNestedSelector string
if err := chromedp.Run(ctx,
// Queries run from the document root by default, so Text will
// pick the first node it finds.
chromedp.Text(".content", &queryRoot, chromedp.ByQuery),
// We can specify a different node to run the query from; in
// this case, we can tailor the search within #section.
chromedp.Text(".content", &queryFromNode, chromedp.ByQuery, chromedp.FromNode(sectionNode)),
// A CSS selector like "#section > .content" achieves the same
// here, but FromNode allows us to use a node obtained by an
// entirely separate step, allowing for custom logic.
chromedp.Text("#section > .content", &queryNestedSelector, chromedp.ByQuery),
); err != nil {
log.Fatal(err)
}
fmt.Println("Simple query from the document root:", queryRoot)
fmt.Println("Simple query from the section node:", queryFromNode)
fmt.Println("Nested query from the document root:", queryNestedSelector)
// Output:
// Simple query from the document root: outer content
// Simple query from the section node: inner content
// Nested query from the document root: inner content
}
func Example_dump() {
ctx, cancel := chromedp.NewContext(context.Background())
defer cancel()
ts := httptest.NewServer(writeHTML(`<!doctype html>
<html>
<body>
<div id="content" style="display:block;">the content</div>
</body>
</html>`))
defer ts.Close()
const expr = `(function(d, id, v) {
var b = d.querySelector('body');
var el = d.createElement('div');
el.id = id;
el.innerText = v;
b.insertBefore(el, b.childNodes[0]);
})(document, %q, %q);`
s := fmt.Sprintf(expr, "thing", "a new thing!")
var buf bytes.Buffer
if err := chromedp.Run(ctx,
chromedp.Navigate(ts.URL),
chromedp.WaitVisible(`#content`),
chromedp.Evaluate(s, nil),
chromedp.WaitVisible(`#thing`),
chromedp.Dump(`document`, &buf, chromedp.ByJSPath),
); err != nil {
log.Fatal(err)
}
fmt.Println("Document tree:")
fmt.Print(buf.String())
// Output:
// Document tree:
// #document <Document>
// html <DocumentType>
// html
// head
// body
// div#thing
// #text "a new thing!"
// div#content [style="display:block;"]
// #text "the content"
}
func Example_documentDump() {
ctx, cancel := chromedp.NewContext(context.Background())
defer cancel()
ts := httptest.NewServer(writeHTML(`<!doctype html>
<html>
<body>
<div id="content" style="display:block;">the content</div>
</body>
</html>`))
defer ts.Close()
const expr = `(function(d, id, v) {
var b = d.querySelector('body');
var el = d.createElement('div');
el.id = id;
el.innerText = v;
b.insertBefore(el, b.childNodes[0]);
})(document, %q, %q);`
s := fmt.Sprintf(expr, "thing", "a new thing!")
var nodes []*cdp.Node
if err := chromedp.Run(ctx,
chromedp.Navigate(ts.URL),
chromedp.Nodes(`document`, &nodes,
chromedp.ByJSPath, chromedp.Populate(-1, true)),
chromedp.WaitVisible(`#content`),
chromedp.Evaluate(s, nil),
chromedp.WaitVisible(`#thing`),
); err != nil {
log.Fatal(err)
}
fmt.Println("Document tree:")
fmt.Print(nodes[0].Dump(" ", " ", false))
// Output:
// Document tree:
// #document <Document>
// html <DocumentType>
// html
// head
// body
// div#thing
// #text "a new thing!"
// div#content [style="display:block;"]
// #text "the content"
}
func ExampleFullScreenshot() {
ctx, cancel := chromedp.NewContext(context.Background())
defer cancel()
var buf []byte
if err := chromedp.Run(ctx,
chromedp.Navigate(`https://google.com`),
chromedp.FullScreenshot(&buf, 90),
); err != nil {
log.Fatal(err)
}
if err := os.WriteFile("fullScreenshot.jpeg", buf, 0o644); err != nil {
log.Fatal(err)
}
fmt.Println("wrote fullScreenshot.jpeg")
// Output:
// wrote fullScreenshot.jpeg
}
func ExampleEvaluate() {
ctx, cancel := chromedp.NewContext(context.Background())
defer cancel()
// Ignore the result:
{
if err := chromedp.Run(ctx,
chromedp.Evaluate(`window.scrollTo(0, 100)`, nil),
); err != nil {
log.Fatal(err)
}
}
// Receive a primary value:
{
var sum int
if err := chromedp.Run(ctx,
chromedp.Evaluate(`1+2`, &sum),
); err != nil {
log.Fatal(err)
}
fmt.Println(sum)
}
// ErrJSUndefined:
{
var val int
if err := chromedp.Run(ctx,
chromedp.Evaluate(`undefined`, &val),
); err != nil {
fmt.Println(err)
}
}
// ErrJSNull:
{
var val int
if err := chromedp.Run(ctx,
chromedp.Evaluate(`null`, &val),
); err != nil {
fmt.Println(err)
}
}
// Accept undefined/null result:
{
var val *int
if err := chromedp.Run(ctx,
chromedp.Evaluate(`undefined`, &val),
); err != nil {
log.Fatal(err)
}
fmt.Println(val)
}
// Receive an array value:
{
var val []int
if err := chromedp.Run(ctx,
chromedp.Evaluate(`[1,2]`, &val),
); err != nil {
log.Fatal(err)
}
fmt.Println(val)
}
// Map and Slice accept undefined/null:
{
var val []int
if err := chromedp.Run(ctx,
chromedp.Evaluate(`null`, &val),
); err != nil {
log.Fatal(err)
}
fmt.Println("slice is nil:", val == nil)
}
// Receive the raw bytes:
{
var buf []byte
if err := chromedp.Run(ctx,
chromedp.Evaluate(`alert`, &buf),
); err != nil {
log.Fatal(err)
}
fmt.Printf("%s\n", buf)
}
// Receive the RemoteObject:
{
var res *runtime.RemoteObject
if err := chromedp.Run(ctx,
chromedp.Evaluate(`alert`, &res),
); err != nil {
log.Fatal(err)
}
if res.ObjectID != "" {
fmt.Println("objectId is present")
}
}
// Output:
// 3
// encountered an undefined value
// encountered a null value
// <nil>
// [1 2]
// slice is nil: true
// {}
// objectId is present
}