QtWebEnginePage.runJavaScript

[Rolln]

https://doc.qt.io/qtforpython/PySide2/QtWebEngineWidgets/QWebEnginePage.html#PySide2.QtWebEngineWidgets.PySide2.QtWebEngineWidgets.QWebEnginePage.runJavaScript

In the C++ class you can use a callback to get the value returned from the javascript but it doesn't appear that you can get a return value/object with PySide2. Any suggestions would be great.

[Rolln]

Here is a basic example...
When using QT, temp = None.
When the same script is run using Selenium, temp = 5.

import sys
import time
from PySide2 import QtCore, QtGui, QtWidgets
from PySide2 import QtWebEngineWidgets
from PySide2.QtWebEngineWidgets import QWebEngineView

app = QtWidgets.QApplication(sys.argv)
view = QtWebEngineWidgets.QWebEngineView()
view.setUrl(QtCore.QUrl("https://google.com"))
view.show()
temp = view.page().runJavaScript('return 1+4')
print(temp)

import sys
import time
from selenium import webdriver

browser_options = webdriver.FirefoxOptions()
browser_options.add_argument('-headless')
browser = webdriver.Firefox(firefox_options=browser_options)
browser.get('https://google.com')
temp = browser.execute_script('return 1+4')
print(temp)
browser.close()
browser.quit()

[skidooman]

I found the answer here:

https://stackoverflow.com/questions/41780435/return-value-from-javascript-to-pyqt5

I faced the same issue, but in PySide. Back in PySide (1) I could do this:

self.page().mainFrame().evaluateJavaScript("getHits()")

but now, there is no more evaluateJavaScript() but a runJavaScript. This function can take only one or two params. Since it is asynchronous, you apparently have to pass a function as the second parameter. When the script finishes execution, it will call that second function and you will then get the data.

[skidooman]

Argh... seems PYQT5 can do this, but not PySide2.

https://bugreports.qt.io/browse/PYSIDE-643

Too bad since doing this was easy in PySide.

[JonB]

@skidooman
We convered this recently in https://forum.qt.io/topic/110659/q_arg-missing-in-python-how-to-use-invokemethod.
A couple of posts there claim workarounds, I didn't look at them but you might want to....