Package Exports

marsdb
marsdb/dist/Collection
marsdb/dist/Cursor
marsdb/dist/CursorObservable
marsdb/dist/Document
marsdb/dist/DocumentModifier
marsdb/dist/IndexManager
marsdb/dist/PromiseQueue

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (marsdb) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

MarsDB

MarsDB is a lightweight client-side database. It based on a Meteor’s minimongo mathing/modifying implementation. It carefully written on ES6, usess modular lodash, have a Promise based interface and may be backed with any storage implementation (LevelUP, LocalStorage, IndexDB, etc). It also supports observable cursors.

MarsDB supports any kind of find/update/remove operations that Meteor’s minimongo does. So, go to the Meteor docs for supported query/modifier operations.

You can use it in any JS environment (Browser, Electron, NW.js, Node.js).

Features

Promise based API
Carefully written on ES6
Supports many of MongoDB query/modify operations – thanks to Meteor’s minimongo
Flexible pipeline – map, reduce, custom sorting function, filtering. All with a sexy JS interface (no ugly mongo’s aggregation language)
Joinable cursor – joining one object with another can’t be simplier
Persistence API – all collections can be stored (and restored) with any kind of storage (in-memory, LocalStorage, LevelUP, etc)
Live queries - just like in Meteor, but with simplier interface

Examples

Using with Angular 1.x

Include marsdb.angular.js after marsdb.min.js and angular.js in your <head>. Then add a MarsDB dependency in your module. That's it. Now you can use $collection factory. For example:

angular.module(‘app’, [‘MarsDB’])
    .controller(function($scope, $collection) {
        const posts = $collection(‘posts’);

        // All methods in $collection returns a $q promise
        // So you don’t need to manually call $digest
        posts.find({authorId: 123}).observe((docs) => {
            $scope.posts = docs;
        }, $scope).then(() => {
            $scope.loaded = true;
        }); 

        // $scope at last argument needed for auto-binding
        // to a “$destroy” event of the scope for stop
        // observing changes. You can call it manually and
        // don’t pass last argument.
    });

You also can use MarsDB within browserify environment. Just require(‘marsdb/dist/angular’) and MarsDB module will be added to the angular. Angular must be defined in a window or must be available as a module require(‘angular’).

Using within non-ES6 environment

The ./dist folder contains already compiled to a ES5 code, but some polyfills needed. For using in a browser you must to include marsdb.polyfills.js before marsdb.min.js. In node.js you need to require(‘marsdb/polyfills’). It sets in a window/global: Promise, Set and Symbol.

Create a collection

import Collection from ‘marsdb’;
import LocalStorageManager from 'marsdb/lib/LocalStorageManager';

// Setup different id generator and storage managers
// Default storage is in-memory
Collection.defaultStorageManager(LocalStorageManager);
Collection.defaultIdGenerator(() => {
  return {
    value: Math.random(),
    seed: 0,
  };
});

const users = new Collection(‘users’);

Find a documents

const posts = new Collection(‘posts’);
posts.find({author: ‘Bob’})
  .sort([‘createdAt’])
  .then(docs => {
    // do something with docs
  });

Find with pipeline (map, reduce, filter)

An order of pipeline methods invokation is important. Next pipeline operation gives as argument a result of a previous operation.

const posts = new Collection(‘posts’);
posts.find()
  .limit(10)
  .sortFunc((a, b) => a - b + 10)
  .filter(doc => Matsh.sqrt(doc.comment.length) > 1.5)
  .map(doc => doc.comments.length)
  .reduce((acum, val) => acum + val)
  .then(result => {
    // result is a sum of coutn of comments
    // in all found posts
  });

Find with observing changes

Observable cursor returned only by a find method of a collection. Updates of the cursor is batched and debounced (default batch size is 20 and debounce time is 1000 / 15 ms). You can change the paramters by batchSize and debounce methods of an observable cursor (methods is chained).

const posts = new Collection(‘posts’);
const stopper = posts.find({tags: {$in: [‘marsdb’, ‘is’, ‘awesome’]}})
  .observe(docs => {
    // invoked on every result change
    // (on initial result too)
    stopper.stop(); // stops observing
  }).then(docs => {
    // invoked once on initial result
    // (after `observer` callback)
  });

Find with joins

Joined objects is not obervable yet.

const users = new Collection(‘users’);
const posts = new Collection(‘posts’);
posts.find()
  .join(doc => {
    // Return a Promise for waiting of the result
    return users.findOne(doc.authorId).then(user => {
      doc.authorObj = user;
      return doc;
    });
  })
  .join(doc => {
    // Also any other “join” mutations supported
    doc.another = _cached_data_by_post[doc._id];

    // You need to return a document, bacause it's
    // a pipeline operation
    return doc;
  });

Inserting

const posts = new Collection(‘posts’);
posts.insert({text: ‘MarsDB is awesome’}).then(docId => {
  // Invoked after persisting document
})
posts.insertAll(
  {text: ‘MarsDB’},
  {text: ‘is’},
  {text: ‘awesome’}
).then(docsIds => {
  // invoked when all documents inserted
});

Updating

const posts = new Collection(‘posts’);
posts.update(
  {authorId: {$in: [1, 2, 3]}},
  {$set: {text: ‘noop’}}
).then(result => {
  console.log(result.modified) // count of modified docs
  console.log(result.updated) // array of updated docs
  console.log(result.original) // array of original docs
});

Removing

const posts = new Collection(‘posts’);
posts.remove({authorId: {$in: [1,2,3]}})
  .then(removedDocs => {
    // do something with removed documents array
  });

Roadmap

Keep track of multiple remove/update documents in selector (allow only if opations.multi passed)
Upsert updating
Indexes support for some kind of simple requests {a: '^b'}, {a: {$lt: 9}}
Some set of backends
Documentation

Contributing

I’m waiting for your pull requests and issues. Don’t forget to execute gulp lint before requesting. Accepted only requests without errors.

License

See License