我需要帮助来确定watson-developer-cloud Node.js函数的正确语法，以将文档插入Watson的Discovery服务

Question

I'm trying to insert JSON documents into a Discovery collection using the Node.js watson-developer-cloud JDK. This is the relevant code:

var DiscoveryV1=require('watson-developer-cloud/discovery/v1');
var discovery=new DiscoveryV1(credentials);

let doc=aSmallValidJsonObject;
let parms={
  environment_id: envID,
  collection_id: collID,
  configuration_id: confID,
  file: {
        value: new Buffer(JSON.stringify(doc)),
        options:{
          contentType:'application/json',
          "Content-Type":'application/json' //just to be sure
        }
     }
  };
discovery.addDocument(parms,
  function(err,results)
    {
    if (err) {...

The error being returned from this call is

"Error: Request must specify either a "metadata" or "file" part"

I have also tried making parms this way:

let parms={
  environment_id: envID,
  collection_id: collID,
  configuration_id: confID,
  metadata:{"Content-Type":"application/json"},
  file:new Buffer(JSON.stringify(doc))
  };

The error I get in this case is

[TypeError: source.on is not a function]

(I traced this error down to line 33 in the library delayed_stream.js )

If I make the metadata field a string (ie, enclose the value in single quotes) in the above parms, I get this error:

Error: The Media Type [application/octet-stream] of the input document is not supported. Auto correction was attempted, but the auto detected media type [text/plain] is also not supported. Supported Media Types are: application/json, application/msword, application/vnd.openxmlformats-officedocument.wordprocessingml.document, application/pdf, text/html, application/xhtml+xml

Can someone tell me what the correct syntax is for this function?

Answer 1

I had the same problem with the watson-developer-cloud SDK and when posting directly to the API without the SDK. The only way I could make it work was ignoring the file and sending my document content as part of the metadata directly to the API (example using request package).

var options = {
    uri:'https://gateway.watsonplatform.net/discovery/api/v1/environments/'+process.env.DISCOVERY_ENVIRONMENT_ID+'/collections/'+process.env.DISCOVERY_COLLECTION_ID+'/documents?version=2016-12-01&configuration_id='+process.env.DISCOVERY_CONFIGURATION_ID,
    method: 'POST',
    formData: {
        metadata: {
            doc: JSON.stringify(doc)
        }
    },
    auth: {
       user: process.env.DISCOVERY_USERNAME,
       pass: process.env.DISCOVERY_PASSWORD
    },
};

request(options, function(err, httpResponse, body){
    if(err){
      console.log(err);
    }
    console.dir(body);
});

You then need to configure your collection to use the document in the metadata for any enrichments and remember to query against the metadata.

Answer 2

Require the FileSystem ( fs ) library to send the document correctly, if you want to send one doc inside your Computer HD. The error seems like the header inside your options isn't recognize. Try the official example or my example:

The Official API Reference show one example to addDocument like:

var DiscoveryV1 = require('watson-developer-cloud/discovery/v1');
var fs = require('fs');

var discovery = new DiscoveryV1({
  username: '{username}',
  password: '{password}',
  version_date: '2017-06-25'
});

var file = fs.readFileSync('{/path/to/file}');

discovery.addDocument(('{environment_id}', '{collection_id}', file),
function(error, data) {
  console.log(JSON.stringify(data, null, 2));
});

With your example:

discovery.addDocument({
    environment_id: yourEnvId,
    collection_id: yourCollId,
    metadata:'{"Content-Type":"application/json"}',
    file: Buffer.from(doc)
}, function(err, data) {
    if (err) {
        return next(err);
    } else {
        return res.json(data)
      }
});