Call classify for Visual Recognition v3 using the fetch API

visual-recognition-fetch.js

// When testing in node you will have to install `form-data` and `node-fetch`. You don't need them in React Native.
// const fetch = require('node-fetch');
// const FormData = require('form-data');

const VISUAL_RECOGNITION_API = 'https://gateway-a.watsonplatform.net/visual-recognition/api';
const CLASSIFY_ENDPOINT = '/v3/classify';
const apiKey = 'API_KEY_HERE'; // replace with a valid API Key

/**
 * Classifies an image using the Visual Recognition service
 * @param {object} params - The parameters
 * @param {Array} [params.classifier_ids] - The array with classifiers ids
 * @param {object} [params.image] - The image to classify
 * @param {string} [params.api_key] - The Visual Recognition api key
 */
const classifyImage = params => {
  const formData = new FormData();

  formData.append('classifier_ids', params.classifier_ids.join(','));
  if (params.image) {
    formData.append('images_file', {
      uri: params.image.uri,
      type: params.image.type,
      name: '_',
    });
  }

  if (params.url) {
    formData.append('url', params.url);
  }

  return fetch(
    `${VISUAL_RECOGNITION_API}${CLASSIFY_ENDPOINT}?api_key=${params.api_key}&version=2016-05-20`,
    {
      method: 'POST',
      body: formData,
    }
  );
};

// Classify a url in node
classifyImage({
  api_key: apiKey,
  classifier_ids: ['windshields_1975276866', 'default'],
  url: 'https://visual-recognition-demo.ng.bluemix.net/images/samples/1.jpg',
// Uncomment the 3 lines below to classify an image in React Native
//   image: {
//     uri:'content://media/external/images/media/15',
//     type: 'image/jpg',
//   },
})
  .then(res => res.json())
  .catch(error => console.error('Error:', error))
  .then(response => console.log('Success:', JSON.stringify(response, null, 2)));

z.out

[germana:~/visual-recognition]$ node fetch.js
Success: {
  "images": [
    {
      "classifiers": [
        {
          "classifier_id": "windshields_1975276866",
          "name": "windshields",
          "classes": [
            {
              "class": "Repair",
              "score": 0.728
            }
          ]
        },
        {
          "classifier_id": "default",
          "name": "default",
          "classes": [
            {
              "class": "autoclave",
              "score": 0.602
            },
            {
              "class": "rocket engine",
              "score": 0.602,
              "type_hierarchy": "/machine/motor/engine/jet engine/rocket engine"
            },
            {
              "class": "jet engine",
              "score": 0.723
            },
            {
              "class": "engine",
              "score": 0.724
            },
            {
              "class": "motor",
              "score": 0.724
            },
            {
              "class": "machine",
              "score": 0.725
            },
            {
              "class": "spacecraft",
              "score": 0.578,
              "type_hierarchy": "/vehicle/craft/spacecraft"
            },
            {
              "class": "craft",
              "score": 0.578
            },
            {
              "class": "vehicle",
              "score": 0.578
            },
            {
              "class": "turbojet engine",
              "score": 0.527,
              "type_hierarchy": "/machine/motor/engine/jet engine/turbojet engine"
            },
            {
              "class": "furnace",
              "score": 0.5,
              "type_hierarchy": "/enclosure/furnace"
            },
            {
              "class": "enclosure",
              "score": 0.5
            },
            {
              "class": "instrument",
              "score": 0.597
            },
            {
              "class": "equipment",
              "score": 0.599
            },
            {
              "class": "coal black color",
              "score": 0.657
            },
            {
              "class": "reddish orange color",
              "score": 0.641
            }
          ]
        }
      ],
      "source_url": "https://visual-recognition-demo.ng.bluemix.net/images/samples/1.jpg",
      "resolved_url": "https://visual-recognition-demo.ng.bluemix.net/images/samples/1.jpg"
    }
  ],
  "images_processed": 1,
  "custom_classes": 2
}