textvalue(section_id) {
		let cval = this.cfgvalue(section_id);

		if (cval == null)
			cval = this.default;

		if (Array.isArray(cval))
			cval = cval.join(' ');

		return (cval != null) ? '%h'.format(cval) : null;
	}
Obtain a textual input representation.

The default implementation of this method returns the HTML-escaped
current input value of the underlying
[LuCI.ui]{@link LuCI.ui.AbstractElement} widget. User code or specific
option element implementations may override this function to apply a
different logic, e.g. to return `Yes` or `No` depending on the checked
state of checkbox elements.

@param {string} section_id
The configuration section ID

@throws {TypeError}
Throws a `TypeError` exception when no `section_id` was specified.

@returns {string}
Returns the text representation of the current input value.