migrated alchemy vision node from alchemy sdk to node sdk

Author: chughts

package.json

@@ -10,6 +10,7 @@
     "request": "~2.53.0",
     "temp": "^0.8.3",
     "qs": "6.x",
+	  "image-type": "^2.0.2",
     "watson-developer-cloud": "^1.2.4"
   },
   "repository": {

services/alchemy_vision/v1.html

@@ -30,6 +30,7 @@
             <option value="imageFaces">Faces</option>
             <option value="imageLink">URLs</option>
             <option value="imageKeywords">Content Tags</option>
+            <option value="imageText">Text</option>            
         </select>
     </div>
     <div class="form-row">
@@ -42,14 +43,17 @@
     <p>Using the Image Analysis node, you can use the Alchemy APIs to analyse images for face detection, content tags and links.</p>
     <p>The following features are available for analysis:</p>
     <ul>
-        <li><b>Faces</b>, discover human faces within the images.</li>
-        <li><b>URLs</b>, discover URLs within the images.</li>
+        <li><b>Faces</b>, discover human faces within the image.</li>
+        <li><b>URLs</b>, extract images from a URL webpage.</li>
         <li><b>Content Tags</b>, extract content tags from the image.</li>
+        <li><b>Text</b>, extract text from the image.</li>        
     </ul>
     <p>For full details on the feature details and response values, please see the <a href="http://www.alchemyapi.com/api">Alchemy API documentation</a></p>
     <p>The content to be analysed should be passed in on <code>msg.payload</code>.</p>
     <p>Valid <code>msg.payload</code> types: URL or Buffer containing raw image bytes.</p>
-    <p>If you need to send custom parameters along with each feature, set those parameters as children of the <code>msg.alchemy_options</code> object.</p>
+    <p>If you need to send custom parameters along with each feature, set those parameters as children of the <code>msg.alchemy_options</code> object.
+       eg. <code>msg.alchemy_options = {knowledgeGraph: 1}</code>
+    </p>
     <br>
     <p>Results from the Alchemy API service will made available at <code>msg.result</code>.</p>
 </script>

services/alchemy_vision/v1.js

@@ -1,5 +1,5 @@
 /**
- * Copyright 2013,2015 IBM Corp.
+ * Copyright 2013,2015, 2016 IBM Corp.
  *
  * Licensed under the Apache License, Version 2.0 (the 'License');
  * you may not use this file except in compliance with the License.
@@ -14,64 +14,171 @@
  * limitations under the License.
  **/
 
+// AlchemyAPI Image Analysis functions supported by this node
 var FEATURE_RESPONSES = {
   imageFaces: 'imageFaces',
   imageLink: "image",
-  imageKeywords: "imageKeywords"
+  imageKeywords: "imageKeywords",
+  imageText: "sceneTextLines"
 };
 
+
 module.exports = function (RED) {
-  var cfenv = require('cfenv'),
-    AlchemyAPI = require('alchemy-api');
+  var cfenv = require('cfenv');
+  var watson = require('watson-developer-cloud');
+
+  var imageType = require('image-type');
+  var url = require('url');
+  var temp = require('temp');
+  var fileType = require('file-type');
+  var fs = require('fs');
+
+  // temp is being used for file streaming to allow the file to arrive so it can be processed. 
+  temp.track();
+
+  // Require the Cloud Foundry Module to pull credentials from bound service 
+  // If they are found then the api key is stored in the variable s_apikey. 
+  //
+  // This separation between s_apikey and apikey is to allow 
+  // the end user to modify the key  redentials when the service is not bound.
+  // Otherwise, once set apikey is never reset, resulting in a frustrated
+  // user who, when he errenously enters bad credentials, can't figure out why
+  // the edited ones are not being taken.
 
-  var services = cfenv.getAppEnv().services,
-    service;
+  // Taking this line out as codacy was complaining about it. 
+  // var services = cfenv.getAppEnv().services,
 
-  var apikey;
+  var apikey, s_apikey;
 
   var service = cfenv.getAppEnv().getServiceCreds(/alchemy/i);
 
   if (service) {
-    apikey = service.apikey;
+    s_apikey = service.apikey;
   }
 
   RED.httpAdmin.get('/alchemy-image-analysis/vcap', function (req, res) {
     res.json(service ? {bound_service: true} : null);
   });
 
+  // Utility functions that check for image buffers, urls and stream data in
+ 
+  function imageCheck(data) {
+    return data instanceof Buffer && imageType(data) !== null;
+  };
+
+  function urlCheck(str) {
+    var parsed = url.parse(str)
+    return (!!parsed.hostname && !!parsed.protocol && str.indexOf(' ') < 0);
+  };
+
+  function stream_buffer(file, contents, cb) {
+    fs.writeFile(file, contents, function (err) {
+      if (err) throw err;
+      cb();
+    });
+  };
+
+  // Utility function that performs the alchemy vision call. 
+  // the cleanup removes the temp storage, and I am not sure whether 
+  // it should be called here or after alchemy returns and passed
+  // control back to cbdone.
+
+  function performAction(params, feature, cbdone, cbcleanup) {
+    var alchemy_vision = watson.alchemy_vision( { api_key: apikey } );
+
+    if (feature == 'imageFaces')
+    {
+      alchemy_vision.recognizeFaces(params, cbdone);
+    } else if (feature == 'imageLink') {
+      alchemy_vision.getImageLinks(params, cbdone);
+    } else if (feature == 'imageKeywords') {
+      alchemy_vision.getImageKeywords(params, cbdone);
+    } else if (feature == 'imageText') {
+      alchemy_vision.getImageSceneText(params, cbdone);
+    }    
+
+    if (cbcleanup) cbcleanup();
+  }
+
+
+  // This is the Alchemy Image Node
+
   function AlchemyImageAnalysisNode (config) {
     RED.nodes.createNode(this, config);
     var node = this;
 
     this.on('input', function (msg) {
       if (!msg.payload) {
+        this.status({fill:'red', shape:'ring', text:'missing payload'}); 
         var message = 'Missing property: msg.payload';
         node.error(message, msg);
         return;
       }
 
-      apikey = apikey || this.credentials.apikey;
+      // If it is present the newly provided user entered key takes precedence over the existing one. 
+      apikey = s_apikey || this.credentials.apikey;
+      this.status({}); 
 
       if (!apikey) {
+        this.status({fill:'red', shape:'ring', text:'missing credentials'});          
         var message ='Missing Alchemy API service credentials'; 
         node.error(message, msg);
         return;
       }
 
-      var alchemy = new AlchemyAPI(apikey);
-
+      // Check which single feature has been requested.
       var feature = config["image-feature"];
 
-      alchemy[feature](msg.payload, msg.alchemy_options || {}, function (err, response) {
-        if (err || response.status === "ERROR") { 
-          var message = 'Alchemy API request error: ' + (err ? err : response.statusInfo); 
-          node.error(message, msg);
-          return;
+      // Splice in the additional options from msg.alchemy_options
+      // eg. The user may have entered msg.alchemy_options = {knowledgeGraph: 1};     
+      var params = {};
+
+      for (var key in msg.alchemy_options) { params[key] = msg.alchemy_options[key]; }
+
+      // This is the callback after the call to the alchemy service.    
+      // Set up as a var within this scope, so it has access to node, msg etc. 
+      // in preparation for the Alchemy service action       
+      var actionComplete = function(err, keywords) {
+        if (err || keywords.status === 'ERROR') {
+          node.status({fill:'red', shape:'ring', text:'call to alchmeyapi vision service failed'}); 
+          console.log('Error:', msg, err);
+          node.error(err, msg);
         }
+        else {
+          msg.result = keywords[FEATURE_RESPONSES[feature]] || [];
+          msg.fullresult = {};
+          msg.fullresult['all'] = keywords;
+          node.send(msg); 
+        }        
+      }        
+      
+      // If the input is an image, need to stream the input in, giving time for the
+      // data to arrive, before invoking the service. 
+      if (imageCheck(msg.payload)) {
+        temp.open({suffix: '.' + fileType(msg.payload).ext}, function (err, info) {
+          if (err) {
+            this.status({fill:'red', shape:'ring', text:'unable to open image stream'});          
+            var message ='Node has been unable to open the image stream'; 
+            node.error(message, msg);
+            return;        
+          }  
+
+          stream_buffer(info.path, msg.payload, function () {
+            params['image'] = fs.createReadStream(info.path);
+            performAction(params, feature, actionComplete, temp.cleanup);        
+          });
+
+        });
+      } else if (urlCheck(msg.payload)) {
+        params['url'] = msg.payload;
+        performAction(params, feature, actionComplete);
+      } else {
+        this.status({fill:'red', shape:'ring', text:'payload is invalid'});          
+        var message ='Payload must be either an image buffer or a string representing a url'; 
+        node.error(message, msg);
+        return;        
+      }
 
-        msg.result = response[FEATURE_RESPONSES[feature]];
-        node.send(msg)
-      })
     });
   }