no_levels_with_route.cpp

This usage:

• There are no levels
• There is only one logger
• The logger has multiple destinations
• We use a custom route

A custom route means you don't want to first run all formatters, and then write to all destinations. Depending on the destination, you'll want a certain formatting of the message

In our example:

to cout:        [idx] [time] message [enter]
to dbg_window:  [time] message [enter]
to file:        [idx] message [enter]

We will use an apply_format_and_write class that caches the formatting, so that it'll format faster (more specifically, the boost::logging::format_and_write::use_cache, together with boost::logging::optimize::cache_string_several_str).

The output will be similar to this:

The debug window

12:15.12 this is so cool 1
12:15.12 hello, world
12:15.12 good to be back ;) 2

The file:

[1] this is so cool 1
[2] hello, world
[3] good to be back ;) 2

The console:

[1] 12:15.12 this is so cool 1
[2] 12:15.12 hello, world
[3] 12:15.12 good to be back ;) 2

#include <boost/logging/format_fwd.hpp>

BOOST_LOG_FORMAT_MSG( optimize::cache_string_several_str<> )

#include <boost/logging/format.hpp>

using namespace boost::logging;


typedef logger_format_write< > logger_type;

BOOST_DECLARE_LOG_FILTER(g_log_filter, filter::no_ts ) 
BOOST_DECLARE_LOG(g_l, logger_type) 

#define L_ BOOST_LOG_USE_LOG_IF_FILTER(g_l(), g_log_filter()->is_enabled() )

BOOST_DEFINE_LOG_FILTER(g_log_filter, filter::no_ts ) 
BOOST_DEFINE_LOG(g_l, logger_type)

void no_levels_with_route_example() {
    //         add formatters and destinations
    //         That is, how the message is to be formatted...
    g_l()->writer().add_formatter( formatter::idx(), "[%] "  );
    g_l()->writer().add_formatter( formatter::time("$hh:$mm.$ss ") );
    g_l()->writer().add_formatter( formatter::append_newline() );

    //        ... and where should it be written to
    g_l()->writer().add_destination( destination::cout() );
    g_l()->writer().add_destination( destination::dbg_window() );
    g_l()->writer().add_destination( destination::file("out.txt") );

    // Now, specify the route
    g_l()->writer().router().set_route()
        .fmt( formatter::time("$hh:$mm.$ss ") ) 
        .fmt( formatter::append_newline() )
        /* 
        Not like this: .fmt( formatter::idx() )

        This is because 
        add_formatter( formatter::idx(), "[%] "  );
        has surrounded formatter::idx() in a spacer - see formatter::spacer
        */
        .fmt( formatter::spacer( formatter::idx(), "[%] ") )
        .clear()
        .fmt( formatter::time("$hh:$mm.$ss ") ) 
        .fmt( formatter::append_newline() )
        .dest( destination::dbg_window() )
        .clear()
        .fmt( formatter::spacer( formatter::idx(), "[%] ") )
        .fmt( formatter::time("$hh:$mm.$ss ") ) 
        .fmt( formatter::append_newline() )
        .dest( destination::cout() )
        .clear()
        .fmt( formatter::spacer( formatter::idx(), "[%] ") )
        .fmt( formatter::append_newline() )
        .dest( destination::file("out.txt") );

    g_l()->mark_as_initialized();

    int i = 1;
    L_ << "this is so cool " << i++;

    std::string hello = "hello", world = "world";
    L_ << hello << ", " << world;

    g_log_filter()->set_enabled(false);
    L_ << "this will not be written anywhere";
    L_ << "this won't be written anywhere either";

    g_log_filter()->set_enabled(true);
    L_ << "good to be back ;) " << i++;
}




int main() {
    no_levels_with_route_example();
}


// End of file

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Copyright John Torjo © 2007
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