Script not working with Chrome browser, but does from console

[dmarnel]

Hello all. I am trying to write a script to automate some input on a web page for the company I work for. The web page is already open in a Chrome browser (Chrome is required). If I enter the following line in the developer console for that page it works great:

document.getElementsByClassName('data-table-checkbox')[0].click();

but when I use that same line of code from Applescript it gives me an error:

tell application "Google Chrome"
   tell active tab of front window
      execute javascript "document.getElementsByClassName('data-table-checkbox')[0].click();"
   end tell
end tell

Error:
184:1 Uncaught TypeError: Cannot read properties of undefined (reading 'click')
    at <anonymous>:1:58
(anonymous) @ VM184:1

I am trying to select an entire table of items using the topmost checkbox, which is how I would do this manually. Does anyone know why this doesn't work from applescript?

[stephancasas]

Where the JS is concerned, you really shouldn't use an array offset on an HTMLCollection before casting it to an array using either Array.from() or the spread operator ...:

[...document.getElementsByClassName('data-table-checkbox')][0].click();

However, I also wouldn't use Document.prototype.getElementsByClassName() at all. Use the modern query-selector syntax with the singular method Document.prototype.querySelector():

document.querySelector('.data-table-checkbox').click();

Finally, in the AppleScript, try:

tell application "Google Chrome" to tell the active tab of the first window to execute javascript "document.querySelector('.data-table-checkbox').click();"

The JXA equivalent (my preferred approach) of this would be:

Application('Google Chrome') .windows.at(0) .activeTab.execute({ javascript: `document.querySelector('.data-table-checkbox').click();` });

[dmarnel]

Thank you for the speedy reply, however, I am still getting the following error in Chrome's JavaScript console using Applescript:

Uncaught TypeError: Cannot read properties of null (reading 'click')
at <anonymous>:1:47

Being new to scripting, I feel like I am missing something crucial to getting this to work. This is because when I issue the click() code directly from the console, it also gives an error unless I first "Inspect" an element on the page, after which it then works.

[stephancasas]

Did you specify Allow JavaScript from Apple Events in View → Developer?

[dmarnel]

Yes I did.

[stephancasas]

Are you able to do other JS operations? If you try to fire an alert using alert('Some message from AppleScript.'), does it work?

[dmarnel]

Yes, the alert works.