add Page.Wait method

page.go

@@ -249,6 +249,26 @@ func (p *Page) HTML() (string, error) {
  return html, nil
 }
 
+//Wait method will cause the browser to spend up to timeout seconds
+//waiting for the element described by the selector to appear.
+//Method for testing or crawling Javascript-modified web pages (eg Ajax)
+// Simple example:
+// page.Wait(`//*[@id="ajax-loaded"]`, 30)
+// fmt.Println(page.HTML())
+func (p *Page) Wait(selector string, timeout int64) *Selection {
+ start := time.Now().Unix()
+ for {
+ if time.Now().Unix()-start > timeout {
+ return nil
+ }
+ node := p.FindByXPath(selector)
+ if num, err := node.Count(); err == nil && num > 0 {
+ return node
+ }
+ time.Sleep(100 * time.Millisecond)
+ }
+}
+
 // RunScript runs the JavaScript provided in the body. Any keys present in
 // the arguments map will be available as variables in the body.
 // Values provided in arguments are converted into javascript objects.