PushContext.java

/**
 * MVEL 2.0
 * Copyright (C) 2007 The Codehaus
 * Mike Brock, Dhanji Prasanna, John Graham, Mark Proctor
 *
 * 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.mvel2.sh.command.basic;

import org.mvel2.MVEL;
import org.mvel2.sh.Command;
import org.mvel2.sh.ShellSession;

public class PushContext implements Command {

  public Object execute(ShellSession session, String[] args) {
    boolean changed = false;
    Object ctx;

    if (args.length == 0) {
      changed = session.pushCtxObject(null);
    }
    else {
      try {
        ctx = MVEL.eval(String.join(" ", args), session.getCtxObject(), session.getVariables());
        if (ctx != null) {
          changed = session.pushCtxObject(ctx);
        }
      }
      catch (Exception ex) {
        System.err.println(ex.getMessage());
      }
    }
    ctx = session.getCtxObject();
    if (changed) {
      System.out.println("Pushed context to " + ctx);
    }
    return ctx;
  }

  public String getDescription() {
    return "pushes the given variable to the current context";
  }

  public String getHelp() {
    return null;
  }
}