Mongoose Polymorphic

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

Setup

    var mongoose = require('mongoose');
    var mongoosePolymorphic = require('mongoose-polymorphic')

    // Create a schema
    var AlertSchema = new mongoose.Schema({
      name: "String"
    });

    // Apply the plugin
    AlertSchema.plugin(mongoosePolymorphic);

    mongoose.model('Alert', AlertSchema);

Usage

    var Item = mongoose.model('Item')
    var item = new Item

    var Alert = mongoose.model("Alert")
    var alert = new Alert

    alert.setItem(item);

    alert.fetchItem(function(err, item){}
      if (err){
        console.log err
      } else {
        console.log item
      }
    });

API

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

    var mongoosePolymorphic = require('mongoose-polymorphic');

    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')}