public HtmlElementSingle(String expression) {
		super(expression);
		String[] secs = StringUtil.split(expression, SPLIT_KV_CHAR);

		String secs0 = secs[0];
		int splitIndex = secs0.indexOf(SPLIT_KI_CHAR);
		this.index = 0;
		if (splitIndex > 0) {
			this.key = secs0.substring(0, splitIndex);
			if (splitIndex < secs0.length() - 1) {
				this.index = Integer.parseInt(secs0.substring(splitIndex + 1));
			}
		} else {
			this.key = secs0;
		}

		this.value = (secs.length < 2 ? null : secs[1]);
	}