javascript - NodeJS async callback. How to return the list, from a async callback? -

so making database query, posts id, add them list, can return. list returned, before callback has finished.

how prevent being returned before callback has finished?

 exports.getblogentries = function(opid) {     var list12 =[];          entry.find({'opid' : opid}, function(err, entries) {              if(!err) {            console.log("adding");              entries.foreach( function(currententry){                   list12.push(currententry);                });              }              else {                 console.log("eeeerroor");             }              //else {console.log("err");}             });     console.log(list12);     return list12;     }; 

all callback asynchronous, don't have guarantee if run in order have leave them.

to fix , make process "synchronous" , guarantee order executation have two solutions:

• first: make process in nested list:

instead of this:

mymodel1.find({}, function(err, docsmodel1) {     callback(err, docsmodel1); });  mymodel2.find({}, function(err, docsmodel2) {     callback(err, docsmodel2); }); 

use this:

mymodel1.find({}, function(err, docsmodel1) {     mymodel2.find({}, function(err, docsmodel2) {         callback(err, docsmodel1, docsmodel2);     }); }); 

the last snippet above guarantee mymodel2 executed after mymodel1 executed.

• second: use framework async. framework awesome , have several helper functions execute code in series, parallels, whatever way want.

example:

async.series(     {         function1 : function(callback) {             //your first code here             //...             callback(null, 'some result here');         },         function2 : function(callback) {             //your second code here (called after first one)             callback(null, 'another result here');         }     },     function(err, results) {         //capture results function1 , function2         //if function1 raise error, function2 not called.          results.function1; // 'some result here'         results.function2; // 'another result here'          //do else...     } );