HTML form to JSON form for auto submission

autoform.ts

/** An object with string keys and values */
type StringOBJ = { [x: string]: string };

/** Generate a JSON representation of a form */
function generateJSONForm(form: HTMLFormElement): StringOBJ {
    // Create empty object
    let object = {} as StringOBJ;

    // Loop through children
    for (let elem of form.children) {
        // Get the name of the element
        let name = elem.getAttribute("name");

        // Make sure the element has a name
        if (!name) continue;

        // Only send select, input or textarea
        if (elem instanceof HTMLSelectElement || elem instanceof HTMLInputElement || elem instanceof HTMLTextAreaElement) {
            // Check if the input is a radio button
            if (elem instanceof HTMLInputElement && elem.type === "radio") {
                if (elem.checked) {
                    // Assign value
                    object[name] = elem.value;
                }
            } else {
                // Assign value
                object[name] = elem.value;
            }
        }
    }

    // Return the completed object
    return object;
}