how to substitute variables within triggers

[igabo johnson]

I've read the tf docs over and over, and I just can't figure out how to do this.

I've got a trigger

/def -mregexp -t"^%{leader} -- 'target (.+)'" leaderTarget = /set target %P1

but it doesn't work.  I know this trigger works because I've manually substituted names for %{leader}, and the target variable gets set.

Can someone please help me out?

[igabo johnson]

Oh yes, and I'm sure the leader variable is set, I checked with /set leader

[Abby Edwards]

I use something like this;

/def follow = /def -mregexp -t"^%{*} leaves ([a-z]*)\\\\.$$" dyn_follow_trig = /send %%P1
/def break_follow = /undef dyn_follow_trig

Then, if I want to follow something that's roaming about, I use /follow <name>, e.g. follow soldier.

This first argument (soldier in this case) is passed to the follow alias, then substituted for the %{*} variable.

The resulting expression is evaluated to generate a second definition, a trigger this time that takes the first parameterized value in the regular expression and sends that verbatim to the connected world; in this case it would be a direction in which to move.

The macro body above uses extra backslashes and dollar signs because of the number of times the expression gets passed over for evaluation; when you call /follow soldier, the macro body gets evaluated and becomes:

/def -mregexp -t"^soldier leaves ([a-z]*)\\.$" dyn_follow_trig = /send %%P1

Does this make sense?  The real key to take away here is that I define an alias that defines a trigger by substituting parameters for %{*}.  You can also use another trigger to call this alias with a parameter to make it dynamic; just make a trigger that calls '/follow <param>'

[Abby Edwards]

I made a mistake above in describing what the macro body becomes.

If I started with:
/def follow = /def -mregexp -t"^%{*} leaves ([a-z]*)\\\\.$$" dyn_follow_trig = /send %%P1

and issued "/follow Soldier", I'd get:
/def -mregexp -t"^Soldier leaves ([a-z]*)\\.$" dyn_follow_trig = /send %P1

(e.g. not %%P1 in the end, but %P1)

So in your case, I'd try this:
/def updateLeader = /set leader %{*} %; /def -mregexp -t"^%{*} -- 'target (.+)'" leaderTarget = /set target %%P1

You'll still have the leader variable set, but it will also redefine your leaderTarget trigger everytime your leader changes.  The %%P1 tells it to not substitute the first parameter when calling updateLeader, but strip one % off and evaluate the new subexpression.  The %P1 then gets replaced with the first parenthetical expression in the regex.

You just call updateLeader when you change leaders.

Hopefully that helps.

[igabo johnson]

That worked like a charm, thanks.  What you said makes sense too; it's just a bit weird since I expected \ to escape the characters, not repeating the special character again (that IS what is happening right?)

Is there any reason why variable substitution isn't allowed in a trigger?  Security related reasons (like injection?)

Also, if I want to use this leader variable for more triggers, can I just %; the end of updateLeader and add it on?  I'm going to test it myself when I get the opportunity, but maybe you can give me an answer before I get to try it out.

Thanks again!

[Ovidiu Androne]

how can i check if a variable is set in an if block? This doesn't work
if (%{first}) \

this neither

if (first) \