bookshelf-model-relations

Provides a way to see what relations/associations a bookshelf model has.

Installation

npm install bookshelf-model-relations --save

Relation definition

The relation definition object that is returned by this module when you pass it a bookshelf model takes the following form:

{
  user: {
    name: 'user', // the name of the relation
    type: 'belongsTo', // belongsTo, hasMany, etc
    modelFrom: 'Post', // always the name of the model passed into bookshelf-model-relations
    keyFrom: 'user_id', // the key on the model desribed in modelFrom
    modelTo: 'User', // the model that is related to via type
    keyTo: 'id', // the key on the model described in modelTo
    modelThrough: null, // if a through model is used (eg. many to many) that model is listed here
    keyThrough: null, // the key on the through model (if present) that points to modelTo
    multiple: false // whether the relation returns a single model or multiple
  },
  comments: {
    name: 'comments',
    type: 'hasMany',
    modelFrom: 'Post',
    keyFrom: 'id',
    modelTo: 'Comment',
    keyTo: 'post_id',
    modelThrough: null,
    keyThrough: null,
    multiple: true
  }
}

Usage

Require the module

const relations = require('bookshelf-model-relations')

Pass it a bookshelf model

const relationships = relations(Post, options)
 
/*
{
  user: {
    name: 'user',
    type: 'belongsTo',
    keyFrom: 'user_id',
    modelFrom: 'Post',
    keyTo: 'id',
    modelTo: 'User',
    keyThrough: null,
    modelThrough: null,
    multiple: false
  },
  comments: {
    name: 'comments',
    type: 'hasMany',
    keyFrom: 'id',
    modelFrom: 'Post',
    keyTo: 'post_id',
    modelTo: 'Comment',
    keyThrough: null,
    modelThrough: null,
    multiple: true
  }
}
*/

options

options.modelName

bookshelf-model-relations attempts to work out the name of the model by taking the value of tableName singularizing it and then UpperCamelCasing it. If this is incorrect, you will need to manually set this via options.modelName like so:

const relationships = relations(Post, {modelName: 'MyCustomClassName'})

Overriding a models relations

bookshelf-model-relations attempts to work out relationships via parsing the model function strings based on bookshelf model definition conventions.

If for some reason your relations are different you can tell bookshelf-model-relations about your models relations in 1 of 2 ways:

relationship comment string

Inside the body of a relationship function you can define a comment string of the format:

/* relationship key1:value1 key2:value2 */

For example:

const Post = bookshelf.Model.extend({
  author: function () {
    /* relationship
      type:belongsTo
      keyFrom:author_id
      modelFrom:Post
      modelTo:Author
      keyTo:id
      modelThrough:null
      keyThrough:null
      multiple:false */
  }
})

relations model property

The other way you can let bookshelf-model-relations know about a model's relations is to define an object on the model under the key relations

For example:

const Post = bookshelf.Model.extend({
  relations: {
    author: {
      type: 'belongsTo',
      keyFrom: 'author_id',
      modelFrom: 'Post',
      modelTo: 'Author',
      keyTo: 'id',
      modelThrough: null,
      keyThrough: null,
      multiple: false
    }
  }
  author: function () { return /*...*/ }
})