fson-db

Data Persistence for DUMMIES

it gives you a magical javascript object that persists changes even after restart, and you can watch for changes too!

both Node.js and Browser environment are supported.

$3

``javascript
//get the magical object
import Fson from 'fson-db';
const starwars = Fson('./file/path');

// save data
starwars.owner = 'Disney';
starwars.movies = [
{
title: 'A New Home',
date: new Date(1997, 5, 25),
directory: {
name: 'George Locas',
}
},
{
title: 'The Force Awakens',
date: new Date(2015, 12, 18),
directory: {
name: 'J.J. Abraham',
}
},
]
//read data just like regular js object
const filtered = starwars.movies.filter(it => it.date.getUTCFullYear() > 2012);
console.log(${filtered.length} movies since ${starwars.owner})

//watch for changes
import {watch} from 'fson-db';
watch(starwars,(field,newValue,oldValue) => {
if (field === 'owner') {
console.log(${newValue} is the new boss here!)
}
if (field === 'movies') {
console.log(a new movie has been released!)
}
})
`

---

#

$3


fson-db load object from DataStorage, keep a copy of object in memory and apply effects to DataStorage.

DataStorage saves data with JSON format in LocalStorage for Browsers and FileSystem for Node.JS.


#

the following apis are supported, full js object apis support is in progress.

Full Example:

`javascript
//browser
import Fson from 'fson-db';

//Node.js
const Fson = require('fson-db');

//specify a directory path
const dbPath = './config';

//db is a js object! but any changes to in will be persistent!
//dbPath is only required for Node.js
const db = Fson(dbPath); //db must be a constant!

//save any type of literals
db.name = 'john doe';
db.age = 24;
db.pi = 3.1415;
db.isActive = true;
db.date = new Date();

//fetch literals
console.log(db.name) // john doe
console.log(db.age) // 24
console.log(db.pi) // 3.1415
console.log(db.isActive) // true
console.log(db.date) // "1997-02-19T20:30:00.000Z"


//save objects!
db.object = {
foo: 'bar',
}

//fetch objest and nested fields
console.log(db.object); // { foo:"bar" }
console.log(db.object.foo); // bar

//modify nested objects
db.object.foo = 'rab';
console.log(db.object.foo); // rab


//save arrays!
db.numbers = [1, 2, 3, 4, 5, 6];

//modify arrays!
db.numbers = db.numbers.filter(i => i % 2 == 0);
console.log(db.numbers); // [ 2, 4, 6 ]

//push to arrays
db.numbers.push(8, 10, 12);
console.log(db.numbers); // [ 2, 4, 6, 8, 9, 10 ]

//save array of objects
db.users = [{id: 1}, {id: 2}]
console.log(db.users[0].id); // 1
console.log(db.users.length); // 2

//modify with indexes!
db.users[1] = {id: 3}
console.log(db.users[1].id); // 3
`

Loop through entries

`javascript
//list entries with Object.keys
db.obj = {
one: 'the_one',
two: 'the_two',
three: 'the_three',
};
console.log(Object.keys(db.obj)) // ['one', 'two', 'three']

//loop through object keys
for (const key in db.obj) {
const value = db.obj[key];
console.log(${key}: ${value});
}

for (const [key, value] of Object.entries(db.obj)) {
console.log(${key}: ${value});
}


//the above example also works for nested objects
`

Delete Operator

`javascript
db.obj = {};
delete db.obj;
console.log(typeof db.obj) // 'undefined'

//nested objects!
db.obj = {
nested: {},
};
delete db.obj.nested;
console.log(typeof db.obj.nested) // 'undefined'
`

Note: high performance is not a priority for now, everything is synchronous, so use db inside async` functions