scrapeGmailDotTrix for so_q_74946967

## for https://stackoverflow.com/q/74946967/6146136
## to scrape JavaScript-generated output from https://gmail.inputekno.com/
############################## sample usage: ##############################
# scrapeGmailDotTrix('usr') # returns
# ['[email protected]', '[email protected]', '[email protected]', '[email protected]']
###########################################################################

## YOU MUST DOWNLOAD CHROMEDRIVER.EXE FOR THIS ##
## https://chromedriver.chromium.org/downloads ##

import sys ## [ just for printing line number in case of error ]
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

def scrapeGmailDotTrix(username: str, wait_start=10, wait_op=200):
    ## validating input arguments ##
    if not (isinstance(wait_start, int) and wait_start > 0): wait_start = 10
    if not (isinstance(wait_op, int)) and wait_op > 0: wait_op = 200

    ## [ XPaths cheatsheet at https://devhints.io/xpath ] ##
    x_inp = '//input[@id="username"][@type="text"]'  # input
    x_ctr = '//label[@id="counter"][@for="emails"]'  # counter
    x_ota = '//textarea[@id="emails"]'  # output textarea

    try:
        driver = webdriver.Chrome()  # no need for path because
        # I copied chromedriver.exe to the same folder as this py file

        ## [just to shorten lines] ##
        isVisible = EC.visibility_of_element_located
        valContains = EC.text_to_be_present_in_element_value
        wait_start = WebDriverWait(driver, wait_start)
        wait_op = WebDriverWait(driver, wait_op)
        findEl = driver.find_element

        ## go to site ##
        driver.get('https://gmail.inputekno.com/')

        ## wait to load input, output textarea and counter ##
        for x in [x_inp, x_ctr, x_ota]:
            try:
                wait_start.until(isVisible((By.XPATH, x)))
            except Exception as e1:
                print(f'Failed to load "{x}" - {type(e1)} Message: "{e1}"')

        ## enter username ##
        findEl(By.XPATH, x_inp).send_keys(str(username))

        ## wait to load {[email protected]} in output ##
        try:
            lastEm = '.'.join(str(username))
            wait_op.until(valContains((By.XPATH, x_ota), lastEm))
        except Exception as e1:
            print(f'Failed to load output - {type(e1)} Message: "{e1}"')

        ## get output value ##
        genEm = findEl(By.XPATH, x_ota).get_attribute('value')

        driver.quit() # close browser
        del driver  # just in case

        ######## split lines and trim whitespace ########
        return [em.strip() for em in genEm.splitlines()]
        ############ list of emails returned ############
        #################################################
    except Exception as e:
        ## in case of error ##
        errMsg = f'{type(e)} on UNKNOWN_LINE - Message: "{str(e)}"'
        try:
            et, em, tb = sys.exc_info() ## get line number ##
            errMsg = f'{et} on line {tb.tb_lineno} - Message: "{em}"'
        except Exception as e2:
            print(f'failed to get errorline  -', str(e2))
        print(f'Error generating emails for "{username}":', errMsg)
        return [] ## return empty list after printing error ##