使用npm安装watson-developer-cloud时出错

Question

I'm following the 'Watson Quickstart for Node.js' found here , but I'm having trouble installing the Watson Developer Cloud Node.js wrapper package using the npm command they provide.

Here's the output: cmd output after npm command

Afterwards, no files appear in the directory in which the command was run. Does anyone have any advice on how to install the Watson Developer Cloud wrapper to begin developing Watson apps with Node.js through Bluemix?

Answer 1

Peter,

The version of the page you're referring to was rewritten entirely more than three months ago. The rewrite should address the issues you've encountered. It appears to be available at the same URL:

http://www.ibm.com/smarterplanet/us/en/ibmwatson/developercloud/doc/getting_started/gs-quick-nodejs.shtml

I'm not sure why you're seeing such an old version of that page. Perhaps it's a stale version from your cache? Please try refreshing the page and see whether that helps.

Answer 2

Ok, so there are a host of problems with the documentation page. I list them below along with the solutions. I was able to get the example working after working around the below shortcomings.

• Machine Translation service does not exist - In the new scheme of things the Machine Translation service is now Language translation service.
• Service credentials are for an incorrect version of the API - The service credential object that you obtained are for the v2 version of the API and not v1 as mentioned within the example source code.

• The source code in the example uses completely outdated request parameters - Refer to the updated source code below.

  var watson = require('watson-developer-cloud');

   var machine_translation = watson.language_translation({ username: 'user_name', password: 'password', version: 'v2' }); //the attributes from and to in the example provided are actually replaced by source and target machine_translation.translate({ text: 'A sentence must have a verb', source : 'enus', target: 'eses' }, function (err, response) { if (err) console.log('error:', err); else console.log(JSON.stringify(response, null, 2)); }); 

Hopefully this solves your problem. Of course, the code shown in the example is only a starter code - in case you want to develop a sophisticated application then you would need to introduce other dependencies such as expressjs, jade etc and then implement these explicitly.

In case you want to refer to the Github repository example for this service visit this link.

Answer 3

Peter,

The npm command should have created a nodes_module in that directory that contains the Watson wrapper APIs. You still need to write a main Node.js file to call the API. The example below is a Node.js file that uses the Language Translation Watson service:

var express = require('express');
var app = express();

app.get('/', function (req, res) {
  res.send('Hello World!');
});

var watson = require('watson-developer-cloud');

var language_translation = watson.language_translation({
  username: '<username>',
  password: '<password>',
  version: 'v2'
});

language_translation.translate({
  text: 'A sentence must have a verb', source : 'en', target: 'es' },
  function (err, translation) {
    if (err)
      console.log('error:', err);
    else
      console.log(JSON.stringify(translation, null, 2));
});

language_translation.identify({
  text: 'The language translation service takes text input and identifies the language used.' },
  function (err, language) {
    if (err)
      console.log('error:', err);
    else
      console.log(JSON.stringify(language, null, 2));
});


var server = app.listen(3000, function () {
  var host = server.address().address;
  var port = server.address().port;

  console.log('Example app listening at http://%s:%s', host, port);
});

It requires express, so you have to first install express and run the Node.js application (assuming you save the file above as app.js, also you need to enter the Watson service username and password as explained in the article you are following):

npm install express
node app.js 

The output is similar to this:

Example app listening at http://:::3000
{
  "translations": [
    {
      "translation": "Una sentencia debe tener un verbo"
    }
  ],
  "word_count": 6,
  "character_count": 27
}
{
  "languages": [
    {
      "language": "en",
      "confidence": 0.913647
    },
    {
      "language": "id",
      "confidence": 0.0323458
    },
    {
      "language": "sv",
      "confidence": 0.0156442
    },
    {
      "language": "fi",
      "confidence": 0.011028
    },
    {
      "language": "is",
      "confidence": 0.00709899
    },
    {
      "language": "nn",
      "confidence": 0.00553699
    },
    {
      "language": "ht",
      "confidence": 0.00408621
    },
    {
      "language": "et",
      "confidence": 0.00119016
    },
    {
      "language": "lv",
      "confidence": 0.00115617
    },
    {
      "language": "de",
      "confidence": 0.00114441
    },
    {
      "language": "tr",
      "confidence": 0.00111117
    },
    {
      "language": "ro",
      "confidence": 0.000802137
    },
    {
      "language": "lt",
      "confidence": 0.000801177
    },
    {
      "language": "cs",
      "confidence": 0.000613459
    },
    {
      "language": "sq",
      "confidence": 0.000474419
    },
    {
      "language": "ku",
      "confidence": 0.000468358
    },
    {
      "language": "bs",
      "confidence": 0.000452145
    },
    {
      "language": "sk",
      "confidence": 0.000396557
    },
    {
      "language": "nb",
      "confidence": 0.000324082
    },
    {
      "language": "hu",
      "confidence": 0.000292984
    },
    {
      "language": "fr",
      "confidence": 0.000289142
    },
    {
      "language": "da",
      "confidence": 0.000274609
    },
    {
      "language": "eo",
      "confidence": 0.000194707
    },
    {
      "language": "eu",
      "confidence": 0.000167031
    },
    {
      "language": "vi",
      "confidence": 0.000147763
    },
    {
      "language": "az",
      "confidence": 0.000121994
    },
    {
      "language": "af",
      "confidence": 0.000111069
    },
    {
      "language": "nl",
      "confidence": 0.0000278278
    },
    {
      "language": "pl",
      "confidence": 0.0000243381
    },
    {
      "language": "pt",
      "confidence": 0.0000127483
    },
    {
      "language": "es",
      "confidence": 0.0000112067
    },
    {
      "language": "ja",
      "confidence": 0.0000018683
    },
    {
      "language": "it",
      "confidence": 5.87651e-7
    },
    {
      "language": "ko",
      "confidence": 4.27166e-7
    },
    {
      "language": "zh",
      "confidence": 1.33964e-7
    },
    {
      "language": "zh-TW",
      "confidence": 6.36584e-8
    },
    {
      "language": "el",
      "confidence": 3.10395e-8
    },
    {
      "language": "hi",
      "confidence": 1.61209e-8
    },
    {
      "language": "ur",
      "confidence": 3.72468e-9
    },
    {
      "language": "mn",
      "confidence": 3.26788e-9
    },
    {
      "language": "ru",
      "confidence": 2.58127e-9
    },
    {
      "language": "he",
      "confidence": 1.91823e-9
    },
    {
      "language": "km",
      "confidence": 1.60638e-9
    },
    {
      "language": "ar",
      "confidence": 1.18306e-9
    },
    {
      "language": "pa",
      "confidence": 1.16591e-9
    },
    {
      "language": "bn",
      "confidence": 9.64752e-10
    },
    {
      "language": "so",
      "confidence": 9.41827e-10
    },
    {
      "language": "ka",
      "confidence": 7.88174e-10
    },
    {
      "language": "uk",
      "confidence": 5.64222e-10
    },
    {
      "language": "ps",
      "confidence": 3.55452e-10
    },
    {
      "language": "ky",
      "confidence": 3.32569e-10
    },
    {
      "language": "fa",
      "confidence": 2.74777e-10
    },
    {
      "language": "ta",
      "confidence": 2.7293e-10
    },
    {
      "language": "be",
      "confidence": 2.71734e-10
    },
    {
      "language": "bg",
      "confidence": 2.33392e-10
    },
    {
      "language": "te",
      "confidence": 2.0307e-10
    },
    {
      "language": "ml",
      "confidence": 1.92155e-10
    },
    {
      "language": "kk",
      "confidence": 1.67796e-10
    },
    {
      "language": "hy",
      "confidence": 1.42515e-10
    },
    {
      "language": "gu",
      "confidence": 1.21276e-10
    },
    {
      "language": "ba",
      "confidence": 6.74764e-11
    },
    {
      "language": "cv",
      "confidence": 4.22054e-11
    }
  ]
}