japan

Japan

JSON patcher

Pull requests are very welcome!

Install

$ npm install [-g] japan

Features

• Patches any JSON input with a series of patches contained in files.

Documentation

Usage

$ jp [options] patch.json [...patches] < data.json

Options

• --pretty, -p

Information

• Patch format
• Operations
• Library usage

Examples

• Serial patching

---

Options

### jp --pretty | -p

Pretty prints resulting data JSON.

---

Information

### Patch format

The patches consist on an array of operations, each one contained in another array:

[
    [<path>, <operation>, <argument>],    
    [<path>, <operation>, <argument>],    
    ...
] 

• path - A path in data object to operate. Supports dot notation, like "a.b.c" or "a.b.0".
• operation - One of the implemented operations.
• argument - Argument for the operation.

---

### Operations

• fetch() - Returns value stored on the selected path.
• put(value) - Adds value to the selected path, creating parent objects as needed.
• remove() - Removes key and contents stored on the selected path.
• move(path) - Moves contents to given path, removing them from the selected path.
• copy(path) - Copy contents to given path.

---

### Library usage

This module also provides a class for using in your Node.js application.

var Patcheable = require('japan').Patcheable;

var data = Patcheable({"a":{"b":2},"c":2}); // Example data object

// Patcheable.prototype.getKey(path)
// Used to get mutable slices of data object on selected path
// NOTE: Throws error if key is not accessible
console.log(data.getKey("a.b")); // { root: { b: 2 }, value: 'b' } 

// Patcheable.prototype.makeKey(path)
// Used to generate mutable slices of data object on selected path
console.log(data.getKey("a.c.x.z")); // { root: { z: {} }, value: 'z' } 

// Common operations
console.log(data.fetch("a")); // { b: 2 }
console.log(data.put("a.c", 3)); // 3
console.log(data.copy("c", "a.b")); // 2
console.log(data.move("a.c", "c")); // 3
console.log(data.remove("c")); // 3

// You can use data as a normal object
console.log(JSON.stringify(data)); // '{"a":{"b":2}}'

---

Examples

### Serial patching

$ echo '{"a":1,"c":2}' > data.json
$ echo '[["d.f", "put", 4], ["c", "move", "a.b.c"]]' > patch1.json
$ echo '[["d", "remove"], ["a.b.c", "copy", "d"], ["a.b.c", "put", 5]]' > patch2.json
$ jp patch1.json patch2.json < data.json

{"a":{"b":{"c":5}},"d":2}