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json-transformer

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

Usage

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"
}

Type of Transformations Supported

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"
}

License

Apache 2.0