/*
 * PatternLayout.hh
 *
 * Copyright 2001, Glen Scott. All rights reserved.
 *
 * See the COPYING file for the terms of usage and distribution.
 */

#ifndef _LOG4CPP_PATTERNLAYOUT_HH
#define _LOG4CPP_PATTERNLAYOUT_HH

#include <log4cpp/Portability.hh>
#include <log4cpp/Layout.hh>

namespace log4cpp {

    /**
     * PatternLayout is a simple fixed format Layout implementation. 
     **/
    class LOG4CPP_EXPORT PatternLayout : public Layout {
        public:
        PatternLayout();
        virtual ~PatternLayout();
        
        // NOTE: All double percentage signs ('%%') followed by a character
        //       in the following comments should actually be a single char.
        //       The doubles are included so that doxygen will print them correctly.
        /**
         * Formats the LoggingEvent in the style set by
		 * the setConversionPattern call. By default, set
		 * to "%%m%%n"
         **/
        virtual std::string format(const LoggingEvent& event);

        /**
         * Sets the format of log lines handled by this
         * PatternLayout. By default, set to "%%m%%n".<br>
         * Format characters are as follows:<br>
         * <li><b>%%</b> - a single percent sign</li>
         * <li><b>%%c</b> - the category</li>
         * <li><b>%%d</b> - the date\n
         *  Date format: The date format character may be followed by a date format 
         *  specifier enclosed between braces. For example, %%d{%%H:%%M:%%S,%%l} or %%d{%%d %%m %%Y %%H:%%M:%%S,%%l}.
         *  If no date format specifier is given then the following format is used:
         *  "Wed Jan 02 02:03:55 1980". The date format specifier admits the same syntax 
         *  as the ANSI C function strftime, with 1 addition. The addition is the specifier
         *  %%l for milliseconds, padded with zeros to make 3 digits.</li>
         * <li><b>%%D</b> - seconds since 1970</li>
         * <li><b>%%m</b> - the message</li>
         * <li><b>%%n</b> - the platform specific line separator</li>
         * <li><b>%%p</b> - the priority</li>
         * <li><b>%%r</b> - milliseconds since this layout was created.</li>
         * <li><b>%%R</b> - seconds since Jan 1, 1970</li>
         * <li><b>%%u</b> - clock ticks since process start</li>
         * <li><b>%%x</b> - the NDC</li>
         * @param conversionPattern the conversion pattern
         * @return true if conversionPattern is a valid
         * conversion pattern, false if it's invalid
         **/
        bool setConversionPattern(std::string conversionPattern);

        private:
        std::string convPatn;	// The conversion pattern set for this layout
        /**
         * Method to format with current conversion pattern, success
         * returned as false if invalid format string (and empty string
         * returned), success returned true and string returned containing
         * message converted according to conversion pattern.
         * The reason for this method is to avoid having to have 
         * "checkValidityOfConversionPattern" code and also
         * "convertUsingConversionPattern" code. With this method,
         * the "setConversionPattern" can call doFormat with a fake
         * LoggingEvent to see if the conversionPattern is valid.
         */
        std::string doFormat(const LoggingEvent& event, 
                             std::string conversionPattern,
                             bool *success);        
    };        
}

#endif // _LOG4CPP_PATTERNLAYOUT_HH