Mongoose Polymorphic

A mongoose plugin to create polymorphic relationships. The relationship enables the extended object to belong to any other mongoose object.

Setup

1
2    var mongoose = require('mongoose');
3    var mongoosePolymorphic = require('mongoose-polymorphic')
4
5    // Create a schema
6    var AlertSchema = new mongoose.Schema({
7      name: "String"
8    });
9
10    // Apply the plugin
11    AlertSchema.plugin(mongoosePolymorphic);
12
13    mongoose.model('Alert', AlertSchema);
14

Usage

1    var Item = mongoose.model('Item')
2    var item = new Item
3
4    var Alert = mongoose.model("Alert")
5    var alert = new Alert
6
7    alert.setItem(item);
8
9    alert.fetchItem(function(err, item){}
10      if (err){
11        console.log err
12      } else {
13        console.log item
14      }
15    });
16

API

mongoose-polymorphic is a mongoose plugin. It takes options to set the association and dynamically creates getters and setters.

1    var mongoosePolymorphic = require('mongoose-polymorphic');
2
3    AlertSchema.plugin(mongoosePolymorphic, options);

By default this will create schema keys 'itemId' and 'itemType'. It also defines methods 'setItem' and 'fetchItem'.

Options:

• associationKey {String} - define a custom association name (defaults to 'item'). This changes the base name of mappings and methods such as associationKey: 'parent' will create mappings 'parentId' and 'parentType'
• promise {Object} - provide a promise library to wrap the async fetchItem method. For example {promise: require('bluebird')}