CODEWITHSUNDEEP
node.jsibm-watson
Octav Zlatior
Octav Zlatior

Reputation: 451

Error in Watson Classifier API reference nodejs example: source.on is not a function

I'm trying to use Watson Classifier from node. I've started by implementing the example in the API reference, found at https://www.ibm.com/watson/developercloud/natural-language-classifier/api/v1/node.html?node#create-classifier

My code (sensitive information replaced with stars):

 58     create: function(args, cb) {
 59         var params = {
 60             metadata: {  
 61                 language: 'en',
 62                 name: '*********************'
 63             }, 
 64             training_data: fs.createReadStream(config.data.prepared.training)
 65         };
 66 
 67         params.training_data.on("readable", function () {
 68             nlc.createClassifier(params, function(err, response) {
 69                 if (err)
 70                     return cb(err);
 71                 console.log(JSON.stringify(response, null, 2));
 72                 cb();
 73             });
 74         });
 75     },

The file I am trying to make a stream from exists. The stream works (I've managed to read from it on "readable"). I've placed the on("readable") part because it made sense for me to do all of this once the stream becomes available, and also because I wanted to be able to check that I can read from it. It does not change the outcome, however.

nlc is the natural_langauge_classifier instance.

I'm getting this:

octav@****************:~/watsonnlu$ node nlc.js create
/home/octav/watsonnlu/node_modules/delayed-stream/lib/delayed_stream.js:33
  source.on('error', function() {});
         ^

TypeError: source.on is not a function
    at Function.DelayedStream.create (/home/octav/watsonnlu/node_modules/delayed-stream/lib/delayed_stream.js:33:10)
    at FormData.CombinedStream.append (/home/octav/watsonnlu/node_modules/combined-stream/lib/combined_stream.js:44:37)
    at FormData.append (/home/octav/watsonnlu/node_modules/form-data/lib/form_data.js:74:3)
    at appendFormValue (/home/octav/watsonnlu/node_modules/request/request.js:321:21)
    at Request.init (/home/octav/watsonnlu/node_modules/request/request.js:334:11)
    at new Request (/home/octav/watsonnlu/node_modules/request/request.js:128:8)
    at request (/home/octav/watsonnlu/node_modules/request/index.js:53:10)
    at Object.createRequest (/home/octav/watsonnlu/node_modules/watson-developer-cloud/lib/requestwrapper.js:208:12)
    at NaturalLanguageClassifierV1.createClassifier (/home/octav/watsonnlu/node_modules/watson-developer-cloud/natural-language-classifier/v1-generated.js:143:33)
    at ReadStream.<anonymous> (/home/octav/watsonnlu/nlc.js:68:8)

I tried debugging it myself for a while, but I'm not sure what this source is actually supposed to be. It's just an object composed of the metadata I put in and the "emit" function if I print it before the offending line in delayed-stream.js.

{ language: 'en',
  name: '*******************',
  emit: [Function] }

This is my package.json file:

  1 {
  2     "name": "watsonnlu",
  3     "version": "0.0.1",
  4     "dependencies": {
  5         "csv-parse": "2.0.0",
  6         "watson-developer-cloud": "3.2.1"
  7     }
  8 }

Any ideas how to make the example work?

Cheers!

Octav

Upvotes: 1

Views: 441

Answers (1)

Octav Zlatior
Octav Zlatior

Reputation: 451

I got the answer in the meantime thanks to the good people at IBM. It seems you have to send the metadata as a stringified JSON:

 59         var params = {
 60             metadata: JSON.stringify({  
 61                 language: 'en',
 62                 name: '*********************'
 63             }), 
 64             training_data: fs.createReadStream(config.data.prepared.training)
 65         };

Upvotes: 1

Related Questions