A Node.js package that converts json from one format to another.

First, install the package using npm:

npm install json-transformer-node --save

Then, require the package and use it like this:

var nodeJsonTransformer = require('json-transformer-node');

var data = {
    x : "xx",
    y : "yy"
}

var transformation = {
    mapping : {
        item : {
            a : "x",
            b : "y"
        }
    }
}

var output = nodeJsonTransformer.transform(data, transformation);
console.log(output);

Output : 
{
    a : "xx",
    b : "yy"
}

1. Object to Object Transformation

    var data = {
        x : "xx",
        y : {
            z: "zz"
        }
    }
    
    var transformation = {
        mapping : {
            item: {
                a : "x",
                b : "y.z" // dot separated path
            }
        }
    }
    
    var output = nodeJsonTransformer.transform(data, transformation);
    console.log(output);
    
    Output : 
    {
        a : "xx",
        b : "zz"
    }
   

2. Array to Array Transformation

        var data = {
            x : "xx",
            y : [{
                z: "z1"
                },
                {
                  z: "z2"
                }]
        }
        
        var transformation = {
            "mapping" :{ 
                "item":{
                    a : "x",
                    b : [{
                        "list" : "y",
                        "item" : {
                            "c" : "z"
                        }
                    }]
                }
            }
        }
        
        var output = nodeJsonTransformer.transform(data, transformation);
        console.log(output);
        
        Output : 
        {
            a : "xx",
            b : [{
                    "c" : "z1"
                },{
                    "c" : "z2"
                }]
        }
   

3. Using Hardcoded values

        var data = {
            x : "xx",
            y : "yy"
        }
        
        var transformation = {
            "mapping" : {
                "item":{
                    a : "x",
                    b : "y",
                    c : "$constantValue"
                }
            }
        }
        
        var output = nodeJsonTransformer.transform(data, transformation);
        console.log(output);
        
        Output : 
        {
            a : "xx",
            b : "yy",
            c : "constantValue"
        }
   

4. Array to Object Transformation

        var data = {
            x : {
                x1 : [{
                        z : "23"
                    },{
                        z : "45"
                    }]
                },
            y : "yy"
        }
        
        var transformation = {
                        "mapping" : {
                            "item":{
                                a : {
                                    "flat" : "x.x1#eq(1)",
                                    "item": {
                                        "c" : "z"
                                    }
                                },
                                b : "y"
                            }
                        }
                    }
        
        var output = nodeJsonTransformer.transform(data, transformation);
        console.log(output);
        
        Output : 
        {
            a : {
                c : "45"
            },
            b : "yy"
        }
        
        Note :  "flat" : "x.x1#eq(1)" means flat it, x.x1 is the dot separated path to the array, 
        eq(index) specifies the index to pick
   

5. Object to Array Transformation

        var data = {
            x : {
                x1 : "123"
            },
            y : 456,
            z : "abc"
        }
        
        var transformation = {
            "mapping" : {
                "item":{
                   "arrayItems": { 
                        "objectify": "x",
                        "item": { 
                            "car": {
                                "c1" : "x1",
                                "c2" : "$abc"
                            }
                         }
                   }
                }
            }
        }
        
        var output = nodeJsonTransformer.transform(data, transformation);
        console.log(output);
        
        Output : 
        { 
          arrayItems: [{ car: { 
                                c1: "123", 
                                c2: "abc" 
                                }
                      }]
        }
   

6. Type Conversion

        var data = {
            x : "123",
            y : 456,
            z : "abc"
        }
        
        var transformation = {
            "mapping" : {
                "item":{
                    a : "x(NUMBER)",
                    b : "y(STRING)",
                    c : "z(UPPER)"
                }
            }
        }
        
        var output = nodeJsonTransformer.transform(data, transformation);
        console.log(output);
        
        Output : 
        {
            a : 123,
            b : "456",
            c : "ABC"
        }
   

7. Operations - depends etc.

        var data = {
            x : "RED",
            y : "Jude"
        }
        
        var transformation = {
            "config": {
                "dependentMap": {
                    "RED": "stop",
                    "GREEN": "go"
                }
            },
            "mapping" : {
                "item":{
                    a : "x{DEPENDS}"
                }
            }
        }
        
        var output = nodeJsonTransformer.transform(data, transformation);
        console.log(output);
        
        Output : 
        {
            a : "stop"
        }
   

Apache 2.0