This is my code:
package main
import (
"context"
"log"
"fmt"
"github.com/chromedp/chromedp"
)
func main() {
queries := [3]string{"Object.keys(window);", "window.CSS", "window.Array"}
// create context
ctx, cancel := chromedp.NewContext(context.Background())
defer cancel()
// run task list
var res []byte
err := chromedp.Run(ctx,
chromedp.Navigate(`https://www.google.com/`),
chromedp.ActionFunc(func(ctx context.Context) error {
for _, query := range queries {
err2 := chromedp.Evaluate(query, &res)
if err2 != nil {
fmt.Printf("error in ActionFunc: %s\n", err2)
}
fmt.Printf("Query %s outputs: %v\n", query, res)
}
return nil
}),
)
if err != nil {
log.Fatal(err)
}
}
What i am trying to do is to navigate to url
to Evaluate and get values for a big list of queries
(I reduced the array to 3 queries for the example).
and then it should just outputs the values from those queries.
But what i get is these errors for every iteration:
error in ActionFunc: %!s(chromedp.ActionFunc=0x7f25a0)
Query Object.keys(window); outputs: []
error in ActionFunc: %!s(chromedp.ActionFunc=0x7f25a0)
Query window.CSS outputs: []
error in ActionFunc: %!s(chromedp.ActionFunc=0x7f25a0)
Query window.Array outputs: []
chromedp.Evaluate does not return error. It returns EvaluateAction. It has Do func which accepts context. So you can try this;
queries := [3]string{"Object.keys(window);", "window.CSS", "window.Array"}
// create context
ctx, cancel := chromedp.NewContext(context.Background())
defer cancel()
// run task list
var res []byte
err := chromedp.Run(ctx,
chromedp.Navigate(`https://www.google.com/`),
chromedp.WaitReady("body"),
//chromedp.Evaluate("Object.keys(window)", &res),
chromedp.ActionFunc(func(ctx context.Context) error {
for _, query := range queries {
chromedp.Evaluate(query, &res).Do(ctx)
fmt.Printf("Query %s outputs: %+v\n", query, string(res))
}
return nil
}),
)
if err != nil {
log.Fatal(err)
}