To help you get started, we've collected the most common ways that ember-local-storage is being used within popular public projects.

Ember localStorage

The addon provides a storageFor computed property that returns a proxy and persists the changes to localStorage or sessionStorage. It works with objects and arrays and has a generator to create the proxy objects or arrays.

It ships with an ember-data adapter that works almost the same as the JSONAPIAdapter with some relationship sugar added.

The idea was taken from Tom Dale's gist Ember Array that writes every change to localStorage and extended to objects. The storageFor API was inspired by Ember State Services.

Installation

• ember install ember-local-storage

Compatibility

Ember	Addon	Node
>= 3.4	>= 2.0	>= 12.x
>= 2.12	< 2.0	>= 10.x

Changelog

See the CHANGELOG

The documentation in this README is for versions >= 2.0.0

• Version 1.x
• Version 0.x

If you upgrade from a version <= 0.1.5 you need to set a legacyKey on the computed storageFor:

export default Ember.Component.extend({
  settings: storageFor('settings', { legacyKey: 'your-old-key' })
});

Usage

• Configuration
• Object & Array
  • Object
  • Array
  • storageFor
  • Methods
• Adapter & Serializer
  • Model
  • .query() & .queryRecord()
  • Import & Export of localStorage records

Configuration

Namespace & keyDelimiter

In you apps config/environment.js you can set a namespace and a keyDelimiter. For backward compatibility this is a opt-in feature.

Important: Don't turn this feature on for existing apps. You will lose access to existing keys.

To activate it there are the following options:

• namespace can be true or a string. If set to true it will use modulePrefix as the namespace
• keyDelimiter is a string. The default is :

// config/environment.js
module.exports = function() {
  var ENV = {
    modulePrefix: 'my-app',
    'ember-local-storage': {
      namespace: true, // will use the modulePrefix e.g. 'my-app'
      namespace: 'customNamespace', // will use 'customNamespace'
      keyDelimiter: '/' // will use / as a delimiter - the default is :
    }
  }
};

ember-data support

This addon autodetects if you use ember-data and will include the support for ember-data adapters and serializes by default. You can opt out of this behavior by setting the includeEmberDataSupport option to false:

// config/environment.js
module.exports = function() {
  var ENV = {
    modulePrefix: 'my-app',
    'ember-local-storage': {
      includeEmberDataSupport: false
    }
  }
};

NOTE: However, there are environments where the detection fails and the support is disabled when you really do want it. A common place you might run into this is on https://ember-twiddle.com. For that case you can force including support for ember-data by turn this option on. Edit the twiddle.json to include the following:

  "ENV": {
    "ember-local-storage": {
      "includeEmberDataSupport": true
    }
  },

Object & Array

Object

Run ember g storage -h for all options.

ember g storage stats
// will generate a localStorage object

ember g storage stats -s
// will generate a sessionStorage object

// app/storages/stats.js

import StorageObject from 'ember-local-storage/local/object';

const Storage = StorageObject.extend();

Storage.reopenClass({
  initialState() {
    return { counter: 0 };
  }
});

export default Storage;

// app/controllers/application.js

import Controller from '@ember/controller';
import { action } from '@ember/object';
import { storageFor } from 'ember-local-storage';

export default class ApplicationController extends Controller {
  @storageFor('stats') stats;

  @action
  countUp() {
    this.incrementProperty('stats.counter');
  }

  @action
  resetCounter() {
    this.get('stats').clear();
    // or
    // this.get('stats').reset();
    // this.set('stats.counter', 0);
  }
}

{{! app/templates/application.hbs}}

<button>Page Visits: {{stats.counter}}</button>
<button>X</button>

Array

Run ember g storage -h for all options.

ember g storage anonymous-likes -a
// will generate a localStorage array

ember g storage anonymous-likes -a -s
// will generate a sessionStorage array

// app/storages/anonymous-likes.js

import StorageArray from 'ember-local-storage/local/array';

const Storage = StorageArray.extend();

// Uncomment if you would like to set initialState
// Storage.reopenClass({
//   initialState() {
//     return [];
//   }
// });

export default Storage;

// app/components/like-item.js

import Component from '@glimmer/component';
import { storageFor } from 'ember-local-storage';
import { action } from '@ember/object';

export default class LikeItemComponent extends Component {
  anonymousLikes: storageFor('anonymous-likes'),

  get isLiked() {
    return this.get('anonymousLikes').includes(this.get('id'));
  }),

  @action
  like(id) {
    this.get('anonymousLikes').addObject(id);
  }
}

{{! app/templates/components/like-item.hbs}}

{{#unless this.isLiked}}
  <button>Like it</button>
{{else}}
  You like it!
{{/unless}}

storageFor options

storageFor(key, model, options)

key String - The filename of the storage (e.g. stats)

model Optional string - The dependent property. Must be an ember data model or an object with modelName and id properties. (It is still experimental)

options are:

• legacyKey String - Deprecated see Deprecations

Methods

The following methods work on StorageObject and StorageArray

.isInitialContent()

You can call .isInitialContent() to determine if content is equal to initialState. Returns a boolean.

.reset()

You can invoke .reset() to reset the content to the initialState.

.clear()

You can invoke .clear() to remove the content from xStorage.

Adapter & Serializer

Important: The Adapter works with ember-data versions >= 1.13 because it depends on JSONAPIAdapter.

If your app is a pure LocalStorage app you just need to create the application adapter and serializer:

// app/adapters/application.js

export { default } from 'ember-local-storage/adapters/local';
// or export { default } from 'ember-local-storage/adapters/session';

// app/serializers/application.js

export { default } from 'ember-local-storage/serializers/serializer';

If you already use Ember Data for non LocalStorage models you can use a per type adapter and serializer.

// app/adapters/post.js

export { default } from 'ember-local-storage/adapters/local';
// or export { default } from 'ember-local-storage/adapters/session';

// app/serializers/post.js

export { default } from 'ember-local-storage/serializers/serializer';

If you use namespaced models e.g. blog/post you have to add the modelNamespace property to the corresponding adapter:

// app/adapters/blog/post.js

import Adapter from 'ember-local-storage/adapters/local';
// or import Adapter from 'ember-local-storage/adapters/session';

export default class BlogPostAdapter extends Adapter {
  modelNamespace = 'blog';
}

Model

Your model is a DS.Model with two new relationship options

// app/models/post.js

import Model, { attr, hasMany } from '@ember-data/model';

export default class PostModel extends Model {
  @attr('string') name;

  @hasMany('comment', { dependent: 'destroy' }) comments;
}

// app/models/comment.js

import Model, { attr, belongsTo } from '@ember-data/model';

export default class CommentModel extends Model {
  @attr('string') name;

  @belongsTo('post', { autoSave: true }) post;
});

Options

• dependent can be used in hasMany relationships to destroy the child records when the parent record is destroyed.
• autoSave can be used in belongsTo relationships to update the association on the parent. It's recommended to use it.

.query() & .queryRecord()

As per ember guides you can query for attributes:

  // with a string
  this.store.query('post', { filter: { name: 'Just a name' } });

  // or a regex
  this.store.query('post', { filter: { name: /^Just(.*)/ } });

Querying relationships also works:

// belongsTo
// get posts from user '123'
this.store.query('post', { filter: { user: '123' } });
this.store.query('post', { filter: { user: { id: '123' } } });
// or regex
this.store.query('post', { filter: { user: /^12/ } });
this.store.query('post', { filter: { user: { id: /^12/ } } });

// belongsTo polymorphic
// get posts from editors
this.store.query('post', { filter: { user: { type: 'editor' } } });
this.store.query('post', { filter: { user: { type: /^ed(.*)ors$/ } } }); // you need to use the plural
// get posts from editor '123'
this.store.query('post', { filter: { user: { id: '123', type: 'editor' } } });
this.store.query('post', { filter: { user: { id: '123', type: /^ed(.*)ors$/ } } }); // you need to use the plural

// hasMany
// get users who've contributed to project.id = 123
this.store.query('user', { filter: { projects: '123' } });
this.store.query('user', { filter: { projects: { id: '123' } } });
// or regex
this.store.query('user', { filter: { projects: /^12/ });
this.store.query('user', { filter: { projects: { id: /^12/ } } });

// hasMany polymorphic
// get users with cats
this.store.query('user', { filter: { pets: { type: 'cat' } } });
// get users with cat '123'
this.store.query('user', { filter: { pets: { id: '123', type: 'cat' } }) };
// get users with cats AND dogs
this.store.query('user', { filter: { pets: [{ type: 'cat' }, { type: 'dog' }] } });
// get users with cats OR dogs
this.store.query('user', { filter: { pets: { type: /cats|dogs/ } } }); // you need to use the plural

You can use queryRecord to return only one record. See the guides for an example.

Import & Export

The addon ships with utility functions that enables export and import of you LocalStorage data. You have to add fileExport option to the environment.js:

// config/environment.js
module.exports = function() {
  var ENV = {
    'ember-local-storage': {
      fileExport: true
    }
  }
};

Import exportData() and importData() from ember-local-storage/helpers/import-export. Both return a Promise.

import Route from '@ember/routing/route';
import { action } from '@ember/object';
import { inject as service } from '@ember/service';
import { importData, exportData } from 'ember-local-storage/helpers/import-export';

export default class IndexRoute extends Route {
  @service store;

  @action
  exportData() {
    exportData(
      this.store,
      ['posts', 'comments'],
      { download: true, filename: 'my-data.json' }
    );
  }

  @action
  importData(event) {
    this.readFile(event.target.files[0]).then((file) => {
      importData(this.store, file.data);
    });
  }

  readFile(file) {
    const reader = new FileReader();

    return new Promise((resolve) => {
      reader.onload = function(event) {
        resolve({
          file: file.name,
          type: file.type,
          data: event.target.result,
          size: file.size,
        });
      };

      reader.readAsText(file);
    });
  }
}

importData(store, content, options)

store the ember data store

content can be a JSON API compliant object or a JSON string

options are:

• json Boolean (default true)
• truncate Boolean (default true) if true the existing data gets replaced.

exportData(store, types, options)

store the ember data store

types Array of types to export. The types must be pluralized.

options are:

• json Boolean (default true)
• download Boolean (default false)
• filename String (default ember-data.json)

Test Helpers

ember-local-storage provides a helper to reset the storage while testing. This could be very useful when part of the logic you are testing depends on the information in the storage.

Take a look at the following acceptance tests.

// ember-mocha

import { describe, afterEach } from 'mocha';
import { setupApplicationTest } from 'ember-mocha';
import setupMirage from 'ember-cli-mirage/test-support/setup-mirage';
import resetStorages from 'ember-local-storage/test-support/reset-storage';

describe('Acceptance | login page', function() {
  let hooks = setupApplicationTest();
  setupMirage(hooks);

  afterEach(function() {
    if (window.localStorage) {
      window.localStorage.clear();
    }
    if (window.sessionStorage) {
      window.sessionStorage.clear();
    }
    resetStorages();
  });

  it('visiting a place', async function() {
    // your test goes here.
  });
});

// ember-qunit

import { module, test } from 'qunit';
import { setupApplicationTest } from 'ember-qunit';
import { visit, currentURL } from '@ember/test-helpers';
import resetStorages from 'ember-local-storage/test-support/reset-storage';

module('basic acceptance test', function(hooks) {
  let hooks = setupApplicationTest(hooks);

  hooks.afterEach(function() {
    if (window.localStorage) {
      window.localStorage.clear();
    }
    if (window.sessionStorage) {
      window.sessionStorage.clear();
    }
    resetStorages();
  });

  test('can visit /', async function(assert) {
    await visit('/');
    assert.strictEqual(currentURL(), '/');
  });
});

Deprecations

ember-local-storage.initializers.local-storage-adapter

until: 3.0.0

The initializer has been deprecated and will be removed in version 3.0.0. This is due to the fact that ember-data >= 4.12 will no longer allow to reopen the Store. To remove the deprecation message you need to use the utility functions provided by the addon:

import { importData, exportData } from 'ember-local-storage/helpers/import-export';

See the Export & Import example. When you are done you need to set loadInitializer to false:

// config/environment.js
module.exports = function() {
  var ENV = {
    'ember-local-storage': {
      loadInitializer: false
    }
  }
};

This will be the default behaviour for apps that use ember-data >= 4.12.

ember-local-storage.mixins.adapters.import-export

until: 3.0.0

Using the import-export mixin has been deprecated and will be removed in version 3.0.0. You should use the utility functions provided by the addon:

import { importData, exportData } from 'ember-local-storage/helpers/import-export';

See the Export & Import example.

ember-local-storage.storageFor.options.legacyKey

until: 2.0.0

Using legacyKey has been deprecated and will be removed in version 2.0.0. You should migrate your key to the new format. For storageFor('settings') that would be storage:settings.

Contributing

See the Contributing guide for details.

Publishing

npx release-it
npm publish --tag latest

License

This project is licensed under the MIT License.