CODEWITHSUNDEEP
javascriptnode.jscallback
Cyph
Cyph

Reputation: 631

callback is not a function: what am i doing wrong?

I'm doing an async call to Redis and trying to use a callback to notify async.js the query has completed. I keep encountering an error stating "callback is not a function".

What am I doing wrong here? 

            "check": function (redisListItem, dataElement, callback) {
                let lookupKey = redisListItem.table + dataElement;
                let virtualField = redisListItem.virtualName;

                client.get(lookupKey, function (err, reply) {
                        if (err) {
                            return callback(err)
                        }
                        else {
                            session.virtual[virtualField] = reply;
                            callback(session);
                        }

                });
            }

The call to "check" is being done as follows:

    "condition": function(R) {
        var self = this;
        async.series([
            function(R){

/////////THE CALL TO CHECK ////////
                R.check(List.redisTables.List.negEmail, self.customer.email)

            }.bind(this,R),
            function(R) {
                R.when(this.virtual.negEmail === "true")
            }.bind(this,R)
        ])
    }

Upvotes: 0

Views: 3116

Answers (1)

adeneo
adeneo

Reputation: 318162

R.check(List.redisTables.List.negEmail, self.customer.email) only has two arguments, the third argument, that should be a function, is missing, i.e. it's undefined

R.check(List.redisTables.List.negEmail, self.customer.email, function(session) {
    // do something when "check()" has completed
})

As a sidenote, you should stick with Node conventions, and pass an error and data

client.get(lookupKey, function (err, reply) {
      if (err) {
           return callback(err, null)
      } else {
           session.virtual[virtualField] = reply;
           callback(null, session);
      }
});

that way you can actually check for errors

R.check(List.redisTables.List.negEmail, self.customer.email, function(err, session) {

    if (err) throw new Error('fail')

    // do something when "check()" has completed
})

Upvotes: 6

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