NAME

       WebCommon::incomingExists - Checks a key exists in user-supplied data

SYNOPSIS

       Bool incomingExists( String key, DataSource ds )

ARGUMENTS

       key The key to check

       ds The source for user-supplied data

DESCRIPTION

       Returns true if the key exists in the data source, and false otherwise.

    // GET /example.cgi?a=1;b=3;b=5;z=;z;z
    val = incomingExists("a",DataGet);
    // val = true
    val = incomingExists("b",DataGet);
    // val = true
    val = incomingExists("c",DataGet);
    // val = false
    val = incomingExists("z",DataGet);
    // val = true

       This  is  useful  for  avoiding  Exceptions  when  using WebCommon.incomingData (3kaya) or
       WebCommon.incomingValue (3kaya) , or for checking if a checkbox has been selected.

AUTHORS

       Kaya standard library by Edwin Brady, Chris Morris  and  others  (kaya@kayalang.org).  For
       further information see http://kayalang.org/

LICENSE

       The Kaya standard library is free software; you can redistribute it and/or modify it under
       the terms of the GNU Lesser General Public License (version 2.1 or any later  version)  as
       published by the Free Software Foundation.

RELATED

       WebCommon.DataSource (3kaya)
       WebCommon.incomingData (3kaya)
       WebCommon.incomingKeys (3kaya)
       WebCommon.incomingValue (3kaya)