打字稿错误：类型“元素”上不存在属性“包含”。

Question

Hi I am listening on a focus event on html dialog and try to check if the current focused element is part of my "dialog" class. see the code below.

$(document).ready(() => {
    document.addEventListener("focus", (event) => {
        var dialog = document.getElementsByClassName("dialog table-storage-dialog");
        var dialogOpen: boolean = true;
        var currentElement: any = event.target;
        if (dialogOpen && !dialog[0].contains(a)) {
            event.stopPropagation();
             $("#dialog table-storage-dialog").focus();
        }
    }, true);
});

but this code throws compilation error "Property 'contains' does not exist on type 'Element'". Any idea what is wrong with this code ?

This code makes sure that when you keep pressing tab when the html dialog is open, focus don't go out of the dialog to background window. it stays within the dialog

Answer 1

A DOM element doesn't have a contains method, just like the error says. I'm thinking you meant to use jQuery instead.

Change this line:

var dialog = document.getElementsByClassName("dialog table-storage-dialog");

to this:

var dialog = $(".dialog, .table-storage-dialog");