IfToken.java

package com.floreysoft.jmte.token;

import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import com.floreysoft.jmte.TemplateContext;
import com.floreysoft.jmte.util.Util;

public class IfToken extends ExpressionToken {
	public static final String IF = "if";

	protected final boolean negated;

	public IfToken(String expression, boolean negated) {
		super(expression);
		this.negated = negated;
	}

	public IfToken(List<String> segments, String expression, boolean negated) {
		super(segments, expression);
		this.negated = negated;
	}

	@Override
	public String getText() {
		if (text == null) {
			text = IF + " " + getExpression();
		}
		return text;
	}

	public boolean isNegated() {
		return negated;
	}

	@Override
	@SuppressWarnings("unchecked")
	public Object evaluate(TemplateContext context) {
		final Object value = evaluatePlain(context);

		final boolean condition;
		if (value == null || value.toString().equals("")
				|| value.toString().equalsIgnoreCase("false")) {
			condition = false;
		} else if (value instanceof Boolean) {
			condition = (Boolean) value;
		} else if (value instanceof Map) {
			condition = !((Map) value).isEmpty();
		} else if (value instanceof Collection) {
			condition = !((Collection) value).isEmpty();
		} else if (value instanceof Iterable) {
			Iterator iterator = ((Iterable) value).iterator();
			condition = iterator.hasNext();
		} else {
			List list = Util.arrayAsList(value);
			// XXX looks strange, but is ok: list will be null if is
			// is not an array which results to true
			condition = list == null || !list.isEmpty();
		}
		boolean evaluated = negated ? !condition : condition;

		return evaluated;
	}

	@Override
	public String emit() {
		return getText();
	}
}