/doc/efun/notify_fail

SYNOPSIS

void notify_fail(string str, int priority)
void notify_fail(closure cl, int priority)

DESCRIPTION

Store str as the error message given instead of the default message ``What ?''.

If a closure is given, it is executed to return the error message string, but not before all attempts to execute the commandline failed (read: not at the time of the call to notify_fail()).

If notify_fail() is called more than once, only the last call will be used.

The idea of this function is to give better error messages instead of simply 'What ?'.

It is also better to use

		notify_fail(message); return 0;

instead of

		write(message); return 1;

Other objects will get the chance to evaluate the verb.

The 'priority' is a Nightfall-specific invention, it allows you to define how badly the command failed. Recognized are are the priorities defined in /sys/config.h

NOTIFY_NOT_CMD (-1):

The object does not support the command at all.

NOTIFY_NOT_OBJ ( 0):

The object supports the command in general, but is not the one meant in the actual command.

NOTIFY_ILL_ARG ( 1):

The object supports the command in general, but is either not the one meant with the actual command, or is given an invalid command (this is needed for commands which do not specifiy the object unambiguously).

NOTIFY_NOT_VALID ( 2)

The object supports the command and _is_ the one meant in the actual command, but can't complete its task due to some internal reason (like syntax errors in the command arguments).

NOTIFY_DO_ALL (max int)

Not a real failure message, this one allows the repeated execution of the same command for other objects (e.g. for a 'wear all').

EXAMPLE

To implement is a command 'foo <object> to <object>', which is available for wizards only, and may also be shortened to 'foo to <object>'.

	#define TP this_player()
	int foo(string arg) {
	  string str1, str2;
	  object obj1, obj2;
	  if (!IS_IMMORTAL(TP)) {
	    notify_fail("Nothing happens.\n", NOTIFY_NOT_CMD);
	    return 0;
	  }
	  // First check for the short form.
	  // Note the _ILL_ARG in case the specified object is not found.
	  if (1 == sscanf(arg, "to %s", str2)) { // Handle short form
	    if (!(obj2 = TP->Search(str2, SEARCH_ENV, SEARCH_OBJECT))) {
	      notify_fail("Foo to what?\n", NOTIFY_ILL_ARG);
	      return 0;
	    }
	    obj1 = this_object();
	  }
	  else { 
	    // Check the long form.
	    if (   2 != sscanf(arg, "%s to %s", str1, str2)
	        || !(obj1 = TP->Search(str1, SEARCH_ENV, SEARCH_OBJECT))
	        || obj1 != this_object()
               ) {
	      notify_fail("Foo what?\n", NOTIFY_NOT_OBJ);
	      return 0;
	    }
	    if (!(obj2 = TP->Search(str2, SEARCH_ENV, SEARCH_OBJECT))) {
	      notify_fail("Foo to what?\n", NOTIFY_NOT_VALID);
	      return 0;
	    }
	  }
	  if (obj2->QueryWeight() > 3000) {
	    notify_fail( "You need a lighter object to foo to.\n"
	               , NOTIFY_NOT_VALID);
	    return 0;
	  }
	  obj2->SetProp("FooedBy", this_object());
	  write("Well, you asked for it, you got it.\n");
	  return 1;
	}

SEE ALSO

add_action

query_verb

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