javascript - How can I bind data to an event in node.js -

here boiled down version of sort of code i've written:

var cb_gen, item, list, label, token;  cb_gen = function (token_string) {     return function (data) {         var msg = "logout of [" + token_string + "] ";         msg += (typeof(data.error) == "undefined") ? "succeeded" : "failed";         console.log(msg);     }; };  (item in list) {     label = "api_" + item;     token = make_token(item);     app_resources.event.once(label, cb_gen(token)); } 

this has side effect of generating callback function each iteration of loop. i'd rather following:

var cb_gen, item, list, label, token;  callback = function (data, token_string) {     var msg = "logout of [" + token_string + "] ";     msg += (typeof(data.error) == "undefined") ? "succeeded" : "failed";     console.log(msg); };  (item in list) {     label = "api_" + item;     token = make_token(item);     app_resources.event.once(label, callback);     app_resources.event.add_bound_data(label, token); } 

of course not aware of such method "add_bound_data". first code listed above work , i'm not in dire need of solution second one. however, if loop gets large, second example nice. i'd appreciate insight in know able share.

• thanks