Added api to find keywordValue

apiroutes.js

@@ -130,4 +130,60 @@ function findKeyword(req, res, next) {
   );
 }
 
+/**
+ * Accepts a Keyword Value parameter and returns full keyword objects for it from the full filter cache
+ * /keyword?kwv=x&kwv=y 
+ */
+router.get(
+  '/keywordValue',
+  findKeywordValue
+);
+
+/**
+ * Finds keyword objects using the full filter cache based on a filter value
+ * NOTE: this makes use of the Promise form of the fs module.
+ * where the APIs are generated by promisyfing fs using bluebird.
+ * @param {object} req 
+ * @param {object} res 
+ * @param {object} next 
+ */
+function findKeywordValue(req, res, next) {
+  const keywordValue = coerceIntoArray(req.query.kwv) ;
+
+  fs.openAsync(filtercache.getCacheFile(), 'r').then(
+    function(fd) {
+      fs.readFileAsync(filtercache.getCacheFile(), 'utf8')
+        .then(
+        function(contents) {
+          let filterObj = JSON.parse(contents);
+          apputils.fsClose(fs, fd);
+          let kwObjs = filterObj.filter.find(
+            filter => filter.name === 'keywords'
+          );
+          let found = [];
+          keywordValue.map( 
+                (value) => {
+                  let filterVal = kwObjs.keyword.find( 
+                      (filter) => filter.value === value
+                    );
+                  if (filterVal !== undefined) {
+                    found.push(filterVal);
+                  }
+                }
+          );
+          res.json({found: found}); 
+        }
+      ).catch(
+        function (error) {
+            winston.log(" error in findKeywordValue " + error.message);
+        }
+      ); 
+    }
+  );
+
+}
+
+const coerceIntoArray = (obj) => 
+    Array.isArray(obj) ? obj : [obj] || [];
+
 module.exports = router;