QWebEngineView - Javascript Callback

Question

What I am ultimately trying to accomplish is to capture the username and password that the user enters into a website. For example, if the user enters "test@example.com" as the email address into Facebook's login, then clicks submit, I want to store that email address in my PyQt Application.

The closest I've come to achieving this has been using a series of JavaScript commands to place a listener on the "Login Button" that returns the current value of the user parameter. My problem is that the callback that PyQt provides is for when the runJavaScript function is completed, not the javascript event listener. I'm wondering if there is any way to capture the callback function from the JavaScript function, or if there is a better way altogether for me to do this.

import os
import sys
from PyQt5.QtWidgets import QApplication, QVBoxLayout, QWidget
from PyQt5.QtCore import QUrl, QEventLoop
from PyQt5.QtWebEngineWidgets import QWebEngineView

class WebPage(QWebEngineView):
    def __init__(self):
        QWebEngineView.__init__(self)
        self.load(QUrl("https://facebook.com"))
        self.loadFinished.connect(self._on_load_finished)
        #self.page().runJavaScript("document.getElementById("myBtn").addEventListener("click", displayDate)", print)

    def _on_load_finished(self):
        print("Finished Loading")
        cmds = ["btn=document.getElementById('u_0_r')",  # Login Button
                "user=document.getElementsByName('email')[0]",
                "function get_username(){return user.value}",
                "btn.addEventListener('click', get_username)"]
        self.page().runJavaScript("; ".join(cmds), lambda x: print("test: %s"  % x))

if __name__ == "__main__":
    app = QApplication(sys.argv)
    web = WebPage()
    web.show()
    sys.exit(app.exec_())  # only need one app, one running event loop

Yes, the example just shows username/email because (correct me if I'm wrong) the principles should be the same — aoh, Jul 21 '17 at 18:39
But you appear to be trying to steal the users' passwords... — ekhumoro, Jul 21 '17 at 18:41
@ekhumoro Less about stealing and more about remembering / auto-filling the user's password each time they enter the browser. Think dashlane/lastpass/chrome-autofill. Happy to take other suggestions if you have them — aoh, Jul 22 '17 at 00:05

score 2 · Accepted Answer · answered Jul 25 '17 at 19:40

I found a work around using the "urlChanged" signal that seems to work so far for my applications

import os
import sys
from PyQt5.QtWidgets import QApplication, QVBoxLayout, QWidget
from PyQt5.QtCore import QUrl, QEventLoop
from PyQt5.QtWebEngineWidgets import QWebEngineView
from PyQt5.QtWebEngineCore import QWebEngineUrlRequestInterceptor

class WebPage(QWebEngineView):
    def __init__(self):
        QWebEngineView.__init__(self)
        self.current_url = ''
        self.load(QUrl("https://facebook.com"))
        self.loadFinished.connect(self._on_load_finished)
        self.urlChanged.connect(self._on_url_change)

    def _on_load_finished(self):
        self.current_url = self.url().toString()

    def _on_url_change(self):
        self.page().runJavaScript("document.getElementsByName('email')[0].value", self.store_value)

    def store_value(self, param):
        self.value = param
        print("Param: " +str(param))

if __name__ == "__main__":
    app = QApplication(sys.argv)
    web = WebPage()
    web.show()
    sys.exit(app.exec_())  # only need one app, one running event loop

QWebEngineView - Javascript Callback

1 Answers1

Linked