Add 'B' binary/buffer type. resolves totemstech#64

lib/ddb.js

@@ -757,9 +757,9 @@ var ddb = function(spec, my) {
 
 
   /**
-   * converts a string, string array, number or number array (scalar)
-   * JSON object to an amazon DynamoDB compatible JSON object
-   * @param json the JSON scalar object
+   * converts a string, string array, number, number array or Buffer (scalar)
+   * JS object to an amazon DynamoDB compatible JSON object
+   * @param json the JS scalar object
    * @throws an error if input object is not compatible
    * @return res the converted object
    */
@@ -785,13 +785,16 @@ var ddb = function(spec, my) {
       }
       return isSS ? {"SS": arr} : {"NS": arr};
     }
-    throw new Error('Non Compatible Field [not string|number|string array|number array]: ' + value);
+    if (value instanceof Buffer) {
+      return { "B": value.toString('base64') };
+    }
+    throw new Error('Non Compatible Field [not string|number|string array|number array|Buffer]: ' + value);
   }
 
 
   /**
    * converts a DynamoDB compatible JSON object into
-   * a native JSON object
+   * a native JS object
    * @param ddb the ddb JSON object
    * @throws an error if input object is not compatible
    * @return res the converted object
@@ -812,6 +815,8 @@ var ddb = function(spec, my) {
             for(var j = 0; j < ddb[i]['NS'].length; j ++) {
               res[i][j] = parseFloat(ddb[i]['NS'][j]);
             }
+          } else if(ddb[i]['B']) {
+            res[i] = new Buffer(ddb[i]['B'], 'base64');
           } else if(ddb[i]['L']) {
             res[i] = [];
             ddb[i]['L'].forEach(function(item) {
@@ -822,7 +827,7 @@ var ddb = function(spec, my) {
             res[i] = objFromDDB(ddb[i]['M']);
           }
           else
-            throw new Error('Non Compatible Field [not "S"|"N"|"NS"|"SS"]: ' + i);
+            throw new Error('Non Compatible Field [not "S"|"N"|"NS"|"SS"|"B"]: ' + i);
         }
       }
       return res;