bjson

bjson

Bind Json: Reactive way to read/write json files.

npm install bjson --save

How it works

When you need to edit a json file, what you do?

1. Read json file.
2. Deserialize json file.
3. Edit parsed object.
4. Serialize new object.
5. Write back into file.

With bjson:

1. Read json file. (Will return parsed object)
2. Edit object. (All changes are reactive. Will write it back into file)

Getting started

Binding json

settings.json

{}

whatever.js

var bjson = require('bjson');
var settings = bjson('settings'); // will read or create settings.json
settings.prop = 'bar';

settings.json:

{
    "prop": "bar"
}

Watching changes with observe

You can watch changes with a instance of Object.observe passed as callback argument.

settings.json:

{
    "prop": "bar"
}

whatever.js

var bjson = require('bjson');
var settings = bjson('settings', function(observe){
    observe.on('change', function(changes){
        console.log('Path:', changes.path);
        console.log('Old Value:', changes.oldValue);
        console.log('New Value:', changes.value);
        console.log('-----');
    });
});

settings.prop = 'foo';
settings.otherprop = 'bar';

Log output:

Path: prop
Old Value: bar
New Value: foo
-----
Path: otherprop
Old Value: undefined
New Value: bar
-----

settings.json:

{
    "prop": "foo",
    "otherprop": "bar"
}

Observe events

var bjson = require('bjson');
var settings = bjson('settings', function(observe){
    observe.on('add', function(changes){});
    observe.on('update', function(changes){});
    observe.on('delete', function(changes){});
    observe.on('reconfigure', function(changes){});
    observe.on('change', function(changes){}); // fired when any of the above events are emitted
});

Observe events callback changes

path: full path to the property, including nesting
name: name of the path
type: name of the event
object: object
value: current value for the given path. same as object[name]
oldValue: previous value of the property

Example:

var bjson = require('bjson');
var settings = bjson('settings', function(observe){
    observe.on('change', function(changes){
        console.log(changes);
    });
});

settings.foo = 'bar'

//log:
// { path: 'foo',
//   name: 'foo',
//   type: 'add',
//   object: { foo: 'bar' },
//   value: 'bar',
//   oldValue: undefined }