Calling variables outside couchdb function?

Question

I'm having alot of trouble getting couchdb's response handlers to do anything useful with node.js and now.js. My aim is to call back to a client or group with certain information that's been found and also sent from a client.

everyone.now.login = function(){
var username = this.now.lusername;
var password = this.now.lpassword;
var test;
db.get(this.now.lusername, function (err, doc, test, username) {
    if (err) {
        console.log(+ username + " doesn't exist!");

    } else  {
        console.log('Found user!');
        console.log(doc);
        test = 1;
   }
    });
    console.log(test);
}

I'm using test as an example here. I declare it outside db.get, assign a value inside to feed back but when console.log is run outside it doesn't have a value.

Am I simply not getting it or is something wrong?

(I do release I can use doc.(whatever value) but there is a particular variable i wanted to pass on back to the client outside of this call)

score 2 · Accepted Answer · answered Apr 17 '12 at 20:00

The test variable will not have a value in the console.log because the CouchDB response has not arrived yet. Your login function executes the following steps.

Set some variables (username, password, and test is undefined)
Begin a CouchDB fetch (for this.now.lusername) with a function assigned to run when it is complete
Run console.log(test) which is still undefined
The CouchDB response completes, and your function from step 2 runs

What I do for things like this is use function calls.

everyone.now.login = function(){
  var username = this.now.lusername;
  var password = this.now.lpassword;

  db.get(this.now.lusername, function (err, doc, test, username) {
    if (err) {
        console.log(+ username + " doesn't exist!");

    } else  {
        console.log('Found user!');
        console.log(doc);
        login_complete(doc);
   }
  });

  function login_complete(doc) {
    console.log('The login finished! Doc is ' + doc)
  }
}

This way the code still looks correct (the "story" of the code mostly flows from top to bottom), but it also executes correctly (the login_complete() function runs only after the login is actually complete).

Calling variables outside couchdb function?

1 Answers1