regex - Ignoring words in an express route -

i have following routes:

app.get('/blah/query.json', dosomething); app.get('/blah/:id.:format', dosomethingelse); 

currently both routes continue on route 1 (query.json) called , route 2 called (:id.:format). how can exclude call route 2 if route 1 called. tried this:

app.get('/blah^\/(?!query)(:id.:format)$', dosomethingelse); 

but this, , several variations of this, didn't seem work. found post references express code here. looking @ code , trying different things still having trouble getting "if not query" expression work.

any thoughts?

what if set semaphore following?:

var sempahore_execute_second = true;  app.get('/blah/query.json', function(req,res,next){     sempahore_execute_second = false; });  app.get('/blah/:id.:format', function(req,res,next){     if (sempahore_execute_second) {         // execute code here.     }; }));  // or better: app.get('/blah/:id.:format', function(req,res,next){     if (sempahore_execute_second) return next();      // execute code here. })); 

i know bit messy , should forward solution, maybe can @ moment.