tapestry/tapestry-framework/src/java/org/apache/tapestry/script/SetToken.java

// Copyright 2004, 2005 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package org.apache.tapestry.script;

import org.apache.hivemind.Location;

/**
 * Like {@link org.apache.tapestry.script.LetToken}, but sets the value from an
 * expression attribute, rather than a body of full content.
 * 
 * @author Howard Lewis Ship
 * @since 2.2
 */

class SetToken extends AbstractToken
{

    private String _key;
    private String _expression;

    SetToken(String key, String expression, Location location)
    {
        super(location);
        _key = key;
        _expression = expression;
    }

    /**
     * Doesn't <em>write</em>, it evaluates the expression and assigns the
     * result back to the key.
     */

    public void write(StringBuffer buffer, ScriptSession session)
    {

        Object value = evaluate(_expression, session);

        session.getSymbols().put(_key, value);
    }

}