Does htmlNode only extend certain document object functions?

[psheehymn]

I am attempting to update the font size of all the table cells using a particular class, so I tried to use the document object method .getElementsByClassName() so I could loop over all the cells. Obviously substituting htmlNode for document, I got the following error from the panel:

Error executing onInit
htmlNode.getElementsByClassName is not a function

Does htmlNode only support a subset of the document object methods?

[ZuperZee]

htmlNode is a ShadowRoot https://developer.mozilla.org/en-US/docs/Web/API/ShadowRoot
It inherets DocumentFragment https://developer.mozilla.org/en-US/docs/Web/API/DocumentFragment

To get classNames from the htmlNode you can use querySelectorAll from the DocumentFragment https://developer.mozilla.org/en-US/docs/Web/API/DocumentFragment/querySelectorAll

htmlNode.querySelectorAll(".class-name")

Or use a child element that has the getElementsByClassName function https://developer.mozilla.org/en-US/docs/Web/API/Element/getElementsByClassName.

htmlNode.lastChild.getElementsByClassName("class-name")

[psheehymn]

htmlNode.querySelectorAll(".class-name") worked perfectly. I also now have a better understanding of where to look for supporting information. Thanks for both!