LogicalFormatParser.java

/*
** Module   : LogicalFormatParser.java
** Abstract : Parse format for OE logical values.
**
** Copyright (c) 2021, Golden Code Development Corporation.
**
** -#- -I- --Date-- ---------------------------------Description---------------------------------
** 001 VVT 20210428 Created initial version.
*/
/*
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU Affero General Public License as
** published by the Free Software Foundation, either version 3 of the
** License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU Affero General Public License for more details.
**
** You may find a copy of the GNU Affero GPL version 3 at the following
** location: https://www.gnu.org/licenses/agpl-3.0.en.html
**
** Additional terms under GNU Affero GPL version 3 section 7:
**
**   Under Section 7 of the GNU Affero GPL version 3, the following additional
**   terms apply to the works covered under the License.  These additional terms
**   are non-permissive additional terms allowed under Section 7 of the GNU
**   Affero GPL version 3 and may not be removed by you.
**
**   0. Attribution Requirement.
**
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**     work or Appropriate Legal Notices displayed by works containing the covered
**     work.  You may not remove from the covered work any author or developer
**     credit already included within the covered work.
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**   1. No License To Use Trademarks.
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**     This license does not grant any license or rights to use the trademarks
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*/
package com.goldencode.p2j.util;

import com.goldencode.p2j.ui.client.format.DisplayFormat;

/**
 * Parse format for OE logical values.
 */
public class LogicalFormatParser
{
   /**
    * The "true" section of format spec was parsed.
    * <p>
    * The default implementation of this method does nothing.
    *  
    * @param startIdx
    *        the section start index in format string, zero-based, inclusive
    * @param endIdx
    *        the section end index in format string, zero-based, exclusive
    */
   protected void visitTrue(final int startIdx, final int endIdx)
   {
      // no-op
   }
   
   /**
    * The "false" section of format spec was parsed.
    * <p>
    * The default implementation of this method does nothing.
    *  
    * @param startIdx
    *        the section start index in format string, zero-based, inclusive
    * @param endIdx
    *        the section end index in format string, zero-based, exclusive
    */
   protected void visitFalse(final int startIdx, final int endIdx)
   {
      // no-op
   }
   
   /**
    * Parse a format string suitable to format {@link logical} values.
    * Call the {@link #visitTrue(int, int)} and {@link #visitFalse(int, int)}
    * after the corresponding format component is parsed.
    * 
    * @param fmt
    *        the format string to parse
    * @throws ErrorConditionException
    *         if the provided string is not a valid logical format.
    */
   public void parse(final String fmt)
   throws ErrorConditionException
   {
      // the empty string or the "/" are problems
      final int len = fmt.length();
      if (len == 0 || fmt.equals("/"))
      {
         DisplayFormat.genValueCannotBeDisplayedError("", fmt);
         return;
      }

      // usually, format strings must have 2 non-empty parts separated by a
      // '/' so let's look for that char
      final int split = fmt.indexOf('/');
      if (split < 0)
      {
         // edge case where there is no '/' at all, use the whole format as the
         // true value
         visitTrue(0, len);
         visitTrue(len, len);
         return;
      }

      /**
       * It is an error in OE if format has more than one slash character. 
       */
      final int secondSlashIndex = fmt.indexOf('/', split + 1);
      if (secondSlashIndex > 0)
      {
         ErrorManager.genInvalidCharError(secondSlashIndex, fmt);
         return;
      }

      visitTrue(0, split);
      visitTrue(split + 1, len);
   }
}