com.igormaznitsa.jcp.cmdline.GlobalVariableHandler Maven / Gradle / Ivy

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/*
 * Copyright 2002-2019 Igor Maznitsa (http://www.igormaznitsa.com)
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 com.igormaznitsa.jcp.cmdline;

import com.igormaznitsa.jcp.context.PreprocessorContext;
import com.igormaznitsa.jcp.expression.Expression;
import com.igormaznitsa.jcp.expression.Value;
import com.igormaznitsa.jcp.utils.PreprocessorUtils;
import java.util.Locale;

/**
 * The handler for global variables, it adds met global variables into the
 * inside storage
 *
 * @author Igor Maznitsa ([email protected])
 */
public class GlobalVariableHandler implements CommandLineHandler {

  private static final String ARG_NAME = "/P:";

  @Override
  public String getDescription() {
    return "define global variable, for instance /P:DEBUG=true (in command line use $ instead \" char)";
  }

  @Override
  public boolean processCommandLineKey(final String key, final PreprocessorContext context) {
    boolean result = false;

    if (!key.isEmpty() && key.toUpperCase(Locale.ENGLISH).startsWith(ARG_NAME)) {

      final String nameAndExpression = PreprocessorUtils.extractTrimmedTail(ARG_NAME, key);

      if (!nameAndExpression.isEmpty()) {

        final String[] split = PreprocessorUtils.splitForEqualChar(nameAndExpression);
        if (split.length != 2) {
          throw context.makeException(
              "Illegal expression for directive '" + ARG_NAME + "' [" + nameAndExpression + ']',
              null);
        }

        final String value = split[0];
        final String expression = split[1];

        if (context.containsGlobalVariable(value)) {
          throw context.makeException("Duplicated global definition [" + value + ']', null);
        }

        final Value resultVal = Expression.evalExpression(expression, context);
        context.setGlobalVariable(value, resultVal);
        result = true;
      }
    }
    return result;
  }

  @Override
  public String getKeyName() {
    return ARG_NAME;
  }
}