[FEATURE]

- Added Utils class
- Added function to transform object from one format to another based on template

Author: Akash Porwal

.gitignore

@@ -31,3 +31,5 @@ node_modules
 
 # Optional REPL history
 .node_repl_history
+
+.idea/

README.md

@@ -1,2 +1,160 @@
-# JSON-Mapper
-Node package for mapping(transforming) one JSON object into another based on a specified template
+JSON-Mapper
+=========
+
+A Node package for mapping(transforming) one JSON object into another based on a specified template
+
+## Installation
+
+  npm install json-mapper --save
+
+## Usage
+
+    var JSONMapper = require('json-mapper');
+    var input = {
+      "id" : 101,
+      "content" : "My first npm package",
+      "latitude" : 28.7123,
+      "longitude" : 78.72346,
+      "user" : {
+        "id" : 201,
+        "name" : "Codeslayer",
+        "interests": [
+          {
+            "id": 301,
+            "tag_id": 401,
+            "tag": "Food",
+            "types": {
+              "id" : 501,
+              "name": "Fast foods",
+              "description": "Unhealthy",
+              "contents": [
+                {
+                  "id" : 601,
+                  "name" : "Pizza"
+                },
+                {
+                  "id" : 602,
+                  "name" : "Chicken Rice"
+                }
+              ]
+            },
+            "createdAt": "2016-03-12T14:59:33.000Z",
+            "updatedAt": "2016-03-12T14:59:33.000Z"
+          },
+          {
+            "id": 302,
+            "tag_id": 402,
+            "tag": "Movie",
+            "types": {
+              "id" : 502,
+              "name": "Comedy",
+              "description": "Fun to watch",
+              "contents": [
+                {
+                  "id" : 603,
+                  "name" : "Scary Movie"
+                },
+                {
+                  "id" : 604,
+                  "name" : "Jumanji"
+                }
+              ]
+            },
+            "createdAt": "2016-03-12T14:59:33.000Z",
+            "updatedAt": "2016-03-12T14:59:33.000Z"
+          }
+        ]
+      }
+    };
+    
+    var template = {
+      "id" : "user_id",
+      "content" : "content",
+      "latitude" : "latitude",
+      "user" : {
+        "desiredKey": "userDetails",
+        "desiredData": {
+          "id": "id",
+          "name": "first_name",
+          "interests": {
+            "desiredKey": "interests",
+            "desiredData": [{
+                "id": "id",
+                "tag": "tag",
+                "types": {
+                  "desiredKey": "mappedTypes",
+                  "desiredData": {
+                    "id" : "type_id",
+                    "name": "type_name",
+                    "description": "type_description",
+                    "contents": {
+                      "desiredKey": "mappedContents",
+                      "desiredData": [{
+                          "id" : "id",
+                          "name" : "name"
+                        }]
+                    }
+                  }
+                }
+              }]
+          }
+        }
+      }
+    };
+
+    var result = JSONMapper.map(input, template);
+    
+##### Result  
+    {
+      "user_id": 101,
+      "content": "My first npm package",
+      "latitude": 28.7123,
+      "userDetails": {
+        "id": 201,
+        "first_name": "Codeslayer",
+        "interests": [
+          {
+            "id": 301,
+            "tag": "Food",
+            "mappedTypes": {
+              "type_id": 501,
+              "type_name": "Fast foods",
+              "type_description": "Unhealthy",
+              "mappedContents": [
+                {
+                  "id": 601,
+                  "name": "Pizza"
+                },
+                {
+                  "id": 602,
+                  "name": "Chicken Rice"
+                }
+              ]
+            }
+          },
+          {
+            "id": 302,
+            "tag": "Movie",
+            "mappedTypes": {
+              "type_id": 502,
+              "type_name": "Comedy",
+              "type_description": "Fun to watch",
+              "mappedContents": [
+                {
+                  "id": 603,
+                  "name": "Scary Movie"
+                },
+                {
+                  "id": 604,
+                  "name": "Jumanji"
+                }
+              ]
+            }
+          }
+        ]
+      }
+    }
+
+## Release History
+
+* 0.1.0 Initial release

Utils.js

@@ -0,0 +1,58 @@
+/**
+ * Created by codeslayer on 3/13/16.
+ */
+
+module.exports = {
+
+  /**
+   * This function checks for empty/null variable/object
+   *
+   * @param obj
+   * @return boolean
+   */
+  isEmpty:function (obj) {
+    // Speed up calls to hasOwnProperty
+    var hasOwnProperty = Object.prototype.hasOwnProperty;
+    // null and undefined are "empty"
+    if (obj == null) return true;
+
+    // Assume if it has a length property with a non-zero value
+    // that that property is correct.
+    if (obj.length && obj.length > 0) return false;
+    if (obj.length === 0)  return true;
+
+    if(obj.toString())
+    // Otherwise, does it have any properties of its own?
+    // Note that this doesn't handle
+    // toString and valueOf enumeration bugs in IE < 9
+      for (var key in obj) {
+        if (hasOwnProperty.call(obj, key)) return false;
+      }
+    if (!isNaN(obj)) {
+      if (obj.toString().length > 0)  return false;
+    }
+
+    return true;
+  },
+
+  /**
+   * Function to check if the variable is an array
+   *
+   * @param a
+   * @return boolean
+   */
+  isArray: function(a) {
+    return (!!a) && (a.constructor === Array);
+  },
+
+  /**
+   * Function to check if the variable is an object
+   *
+   * @param a
+   * @return boolean
+   */
+  isObject: function(a) {
+    return (!!a) && (a.constructor === Object);
+  }
+
+};

index.js

@@ -0,0 +1,75 @@
+/**
+ * Created by codeslayer on 3/13/16.
+ */
+
+var JSONMapper = {
+
+  /**
+   * Routes request to mapObject function after sanitation checks in input/mapping
+   *
+   * @param {JSON} input, {JSON} mapping
+   * @return {JSON}
+   */
+  map: function(input, mapping){
+    if(Utils.isEmpty(input) || Utils.isEmpty(mapping)){
+      return null
+    }
+
+    return JSONMapper.mapObject(input,mapping);
+  },
+
+  /**
+   * This function iterates the specified mapping and populates the desired keys from the input
+   *
+   * @param {JSON} input, {JSON} mapping
+   * @return {JSON}
+   */
+  mapObject: function(input, mapping){
+    var mappedObject = {};
+
+    for(var actualKey in mapping){
+      /*
+       -> if an object or array needs to be mapped, we take the desired key name and data to be mapped inside an object,
+        and parse all the keys in data one by one and set the mapped output against the desired key name
+       -> if a single variable needs to be mapped, we set the desired value against the desired key
+       */
+      if(Utils.isObject(mapping[actualKey])){
+        var desiredKeyName = mapping[actualKey]['desiredKey'];
+        var desiredDataMapping = mapping[actualKey]['desiredData'];
+
+        if(Utils.isObject(desiredDataMapping)){
+          mappedObject[desiredKeyName] = JSONMapper.mapObject(input[actualKey],desiredDataMapping);
+        }
+        else if(Utils.isArray(desiredDataMapping)){
+          mappedObject[desiredKeyName] = JSONMapper.mapArray(input[actualKey],desiredDataMapping[0]);
+        }
+      }
+      else{
+        var desiredKeyName = mapping[actualKey];
+        mappedObject[desiredKeyName] = input[actualKey];
+      }
+    }
+
+    return mappedObject;
+  },
+
+  /**
+   * This function iterates an array and maps each object of the array one by one
+   *
+   * @param {JSON} input, {JSON} mapping
+   * @return {JSON Array}
+   */
+  mapArray: function(input, mapping){
+    var mappedArray = [];
+    for(var index in input){
+      var inputObject = input[index];
+      var mappedObject = JSONMapper.mapObject(inputObject,mapping);
+      mappedArray.push(mappedObject);
+    }
+
+    return mappedArray;
+  }
+
+};
+
+module.exports = JSONMapper;

package.json

@@ -0,0 +1,26 @@
+{
+  "name": "json-mapper",
+  "version": "0.1.0",
+  "description": "Node package for mapping(transforming) one JSON object into another based on a specified template",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/codeslayer1/JSON-Mapper.git"
+  },
+  "keywords": [
+    "json",
+    "mapping",
+    "mapper",
+    "transform",
+    "convert"
+  ],
+  "author": "codeslayer1",
+  "license": "ISC",
+  "bugs": {
+    "url": "https://github.com/codeslayer1/JSON-Mapper/issues"
+  },
+  "homepage": "https://github.com/codeslayer1/JSON-Mapper#readme"
+}