"TypeError: 'null' is not an object" when first time execute code

Question

Ghost is giving me this error when I execute fallowing code:

    from ghost import Ghost
    from bs4 import BeautifulSoup

    url = "https://wyszukiwarkaregon.stat.gov.pl/appBIR/index.aspx"
    ghost = Ghost()

    page, resources = ghost.open(url)
    page, resources = ghost.evaluate(
         "document.getElementById('btnNowaCaptcha').click();")
    soup = BeautifulSoup(ghost.content)
    capcha = soup.find(id='imgCaptch')

But when I use pdb and execute once more last two lines everything is fine. Is anyone know why?

Could it be that it is is too fast? You're evaluating too soon — Antti Haapala -- Слава Україні, Feb 19 '15 at 19:04
Although my gut-feeling would be that the `gost` methods return `null` for some conditions, and you're not checking for that before trying to operate on the returned objects. — aruisdante, Feb 19 '15 at 19:05
Bah, I've been jumping between languages way too much lately. Of course you're correct. — aruisdante, Feb 19 '15 at 19:07

Antti Haapala -- Слава Україні · Answer 1 · 2015-02-19T19:13:38.137

3

I guess the page did not load fully yet, thus document.getElementById('btnNowaCaptcha') would return null; you should add

ghost.wait_for_page_loaded()  # and/or
ghost.wait_for_selector("#btnNowaCaptcha")

before the ghost.evaluate to make sure that the page is fully loaded.

edited Feb 19 '15 at 19:13

answered Feb 19 '15 at 19:06

Antti Haapala -- Слава Україні

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Unfortunately I have still the same error. `(Pdb) 2015-02-19T21:05:04.1424376304 Ghost(): https://wyszukiwarkaregon.stat.gov.pl/appBIR/scripts/appbir.js(1500): TypeError: 'null' is not an object (evaluating 'document.getElementById(widocznaKarta).style')` – Paweł Babicz Feb 19 '15 at 20:08
So does this give a Python traceback? this just means that the scripts on that page are buggy – Antti Haapala -- Слава Україні Feb 20 '15 at 05:07

"TypeError: 'null' is not an object" when first time execute code

1 Answers1