mobx-orm

library0.5.0-alpha.8jsnpmunverified

A MobX-based ORM (Object-Relational Mapping) library for managing API resources and other asynchronous data sources. Current stable version is 0.5.0-alpha.8, with a development cadence that has slowed since 2019. It integrates tightly with MobX, leveraging observable state and computed properties to manage relationships like belongsTo, hasMany, and hasOne. Key differentiators: unlike plain MobX stores, it provides a structured model layer with built-in normalization, foreign key resolution, and query support for API data, reducing boilerplate for complex data-fetching apps. However, it is in early alpha, lacks full CRUD, and may have breaking changes.

database

npm install mobx-orm

package ↗

INSTALL

IMPORT

SIG · MOBX-ORM

mobx-orm

databasejavascriptv0.5.0-alpha.8

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

Model

✓ import { Model } from 'mobx-orm'

✗ const Model = require('mobx-orm').Model

ESM only; CommonJS require not supported with default export structure.

Repository

✓ import { Repository } from 'mobx-orm'

✗ import Repository from 'mobx-orm'

Repository is a named export, not default.

belongsTo

✓ import { belongsTo } from 'mobx-orm'

A decorator function for belongsTo relations.

Defines Author and Post models with relationships, adds records, and accesses related data via MobX observables.

import { Model, Repository, belongsTo, hasMany } from 'mobx-orm'; import { observable } from 'mobx'; class Author extends Model { static entity = 'authors'; @observable name = ''; @hasMany('Post') posts; } class Post extends Model { static entity = 'posts'; @observable title = ''; @observable text = ''; @belongsTo('Author') author; } // Create repository instances const authorRepo = new Repository(Author); const postRepo = new Repository(Post); // Add records (simulates API response data) authorRepo.add({ id: 1, name: 'Alice' }); postRepo.add({ id: 10, title: 'Hello', text: 'World', author: 1 }); // Access related data via computed properties const post = postRepo.first({ id: 10 }); console.log(post.author?.name); // 'Alice'

Debug

Known issues

breakingMobX-ORM requires MobX v4.10.0+, which introduces breaking changes from MobX v3 (e.g., reaction API changes).

fix

Use MobX v4.10.0+ for compatibility; if on MobX v5+, may need shim or upgrade.

affects: >=0.5.0-alpha.4

deprecatedModel decorators may be deprecated in future versions in favor of standard class syntax.

fix

Consider using non-decorator patterns if stability is required.

affects: >=0.5.0-alpha.0

gotchaRelationships rely on foreign keys stored as property values; incorrect data types can cause silent failures.

fix

Ensure foreign key values match the related model's primary key type (string vs number).

affects: all

gotchaRepository.add() does not deep-merge nested objects; expect flat foreign keys.

fix

Flatten nested API responses manually or use a custom normalization step before adding.

affects: all

Errors

Common errors & fixes

TypeError: Class extends value undefined is not a constructor or null

Model base class import failed or package not properly installed.

fix

Verify mobx-orm is installed with peer dependency mobx: npm install mobx-orm mobx

Module not found: Can't resolve 'mobx'

Missing peer dependency mobx.

fix

Install mobx: npm install mobx

Cannot assign to 'author' because it is a read-only property

Attempting to assign to a @belongsTo property directly (it is computed).

fix

Use repository.update() or set the foreign key value on the model (e.g., post.authorId = 2).

Upgrade

Version history

0.5.0-alpha.8latest on npm

Audit

Dependencies

mobxrequiredCore peer dependency for observables (v4.10.0 or higher).

Agent activity

2 hits · last 30 days

node

Resources

packagemobx-orm ↗