com.eyeq.pivot4j.ui.condition.ExpressionCondition.java Source code

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Here is the source code for com.eyeq.pivot4j.ui.condition.ExpressionCondition.java

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/*
 * ====================================================================
 * This software is subject to the terms of the Common Public License
 * Agreement, available at the following URL:
 *   http://www.opensource.org/licenses/cpl.html .
 * You must accept the terms of that agreement to use this software.
 * ====================================================================
 */
package com.eyeq.pivot4j.ui.condition;

import java.io.Serializable;

import org.apache.commons.configuration.HierarchicalConfiguration;

import com.eyeq.pivot4j.el.ExpressionEvaluator;
import com.eyeq.pivot4j.ui.RenderContext;

public class ExpressionCondition extends AbstractCondition {

    public static final String NAME = "expression";

    private String expression;

    /**
     * @param conditionFactory
     */
    public ExpressionCondition(ConditionFactory conditionFactory) {
        super(conditionFactory);
    }

    /**
     * @param conditionFactory
     * @param expression
     */
    public ExpressionCondition(ConditionFactory conditionFactory, String expression) {
        super(conditionFactory);

        this.expression = expression;
    }

    /**
     * @see com.eyeq.kona.equation.AbstractCondition#getName()
     */
    public String getName() {
        return NAME;
    }

    /**
     * @return the expression
     */
    public String getExpression() {
        return expression;
    }

    /**
     * @param expression
     *            the expression to set
     */
    public void setExpression(String expression) {
        this.expression = expression;
    }

    /**
     * @see com.eyeq.pivot4j.ui.condition.Condition#matches(com.eyeq.pivot4j.ui.RenderContext)
     */
    @Override
    public boolean matches(RenderContext context) {
        if (expression == null) {
            throw new IllegalStateException("Missing expression statement.");
        }

        ExpressionEvaluator evaluator = context.getExpressionEvaluator();

        Object result = evaluator.evaluate(expression, context.getExpressionContext());

        if (result != null) {
            return "true".equalsIgnoreCase(result.toString().trim());
        } else {
            return false;
        }
    }

    /**
     * @see com.eyeq.pivot4j.state.Bookmarkable#saveState()
     */
    @Override
    public Serializable saveState() {
        return expression;
    }

    /**
     * @see com.eyeq.pivot4j.state.Bookmarkable#restoreState(java.io.Serializable)
     */
    @Override
    public void restoreState(Serializable state) {
        if (state == null) {
            this.expression = null;
        } else {
            this.expression = (String) state;
        }
    }

    /**
     * @see com.eyeq.pivot4j.ui.condition.AbstractCondition#saveSettings(org.apache.commons.configuration.HierarchicalConfiguration)
     */
    @Override
    public void saveSettings(HierarchicalConfiguration configuration) {
        super.saveSettings(configuration);

        if (expression == null) {
            return;
        }

        configuration.addProperty("expression", expression);
    }

    /**
     * @see com.eyeq.pivot4j.state.Configurable#restoreSettings(org.apache.commons.configuration.HierarchicalConfiguration)
     */
    @Override
    public void restoreSettings(HierarchicalConfiguration configuration) {
        this.expression = configuration.getString("expression");
    }

    /**
     * @see com.eyeq.pivot4j.ui.condition.AbstractCondition#toString()
     */
    @Override
    public String toString() {
        StringBuilder builder = new StringBuilder();
        builder.append("eval(");

        if (expression != null) {
            builder.append(expression);
        }

        builder.append(")");

        return builder.toString();
    }
}