How do I define methods in a Mongoose model?

Question

My locationsModel file:

mongoose = require 'mongoose'
threeTaps = require '../modules/threeTaps'

Schema = mongoose.Schema
ObjectId = Schema.ObjectId

LocationSchema =
  latitude: String
  longitude: String
  locationText: String

Location = new Schema LocationSchema

Location.methods.testFunc = (callback) ->
  console.log 'in test'


mongoose.model('Location', Location);

To call it, I'm using:

myLocation.testFunc {locationText: locationText}, (err, results) ->

But I get an error:

TypeError: Object function model() {
    Model.apply(this, arguments);
  } has no method 'testFunc'

pdoherty926 · Answer 1 · 2019-12-15T17:19:20.603

51

You didn't specify whether you were looking to define class or instance methods. Since others have covered instance methods, here's how you'd define a class/static method:

animalSchema.statics.findByName = function (name, cb) {
    return this.find({ 
        name: new RegExp(name, 'i') 
    }, cb);
}

edited Dec 15 '19 at 17:19

answered Aug 15 '13 at 19:25

pdoherty926

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Just to complete your answer this is usage example (from same page): `var Animal = mongoose.model('Animal', animalSchema);` Animal.findByName('fido', function (err, animals) {console.log(animals)}); – Wax Cage Apr 15 '15 at 13:37
Hooray for static! That what I was looking for – Vaiden Sep 14 '17 at 08:27
2

this.find is not defined. What could be the reason? – Ramesh Pareek Apr 17 '18 at 17:49

score 33 · Answer 2 · edited Aug 12 '13 at 18:31

33

Hmm - I think your code should be looking more like this:

var mongoose = require('mongoose'),
    Schema = mongoose.Schema,
    ObjectId = Schema.ObjectId;

var threeTaps = require '../modules/threeTaps';


var LocationSchema = new Schema ({
   latitude: String,
   longitude: String,
   locationText: String
});


LocationSchema.methods.testFunc = function testFunc(params, callback) {
  //implementation code goes here
}

mongoose.model('Location', LocationSchema);
module.exports = mongoose.model('Location');

Then your calling code can require the above module and instantiate the model like this:

 var Location = require('model file');
 var aLocation = new Location();

and access your method like this:

  aLocation.testFunc(params, function() { //handle callback here });

edited Aug 12 '13 at 18:31

Owen

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answered Sep 16 '11 at 17:39

iZ.

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Sorry if I'm misreading here, but I don't see how this differs from the OPs code. – Will Sep 13 '13 at 19:57
Can the same method be used somehow using mongoDB shell? – p0lAris Nov 01 '13 at 02:02
@Will, I think the difference is that iZ. is applying the function to the Schema not the Model. – kim3er Nov 20 '13 at 12:16

score 20 · Answer 3 · edited Aug 30 '13 at 10:50

20

See the Mongoose docs on methods

var animalSchema = new Schema({ name: String, type: String });

animalSchema.methods.findSimilarTypes = function (cb) {
  return this.model('Animal').find({ type: this.type }, cb);
}

edited Aug 30 '13 at 10:50

mikemaccana

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answered Aug 24 '12 at 23:06

Duncan_m

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The problem is, in my execution, I get "animal.findSimilarTypes is not a function" message! – ramazan polat Sep 17 '16 at 21:42
In my case, with the exact same example`this.model` is undefined. Any idea why? – Carlos Pinto Jul 08 '17 at 09:17
3

Answering myself, the issue was because I used an arrow function for one of the Schema methods, which was using the scope of the schema and not the instance model itself. – Carlos Pinto Jul 08 '17 at 09:21

score 1 · Answer 4 · edited Oct 05 '14 at 01:19

1

Location.methods.testFunc = (callback) ->
  console.log 'in test'

should be

LocationSchema.methods.testFunc = (callback) ->
  console.log 'in test'

The methods have to be a part of the schema. Not the model.

edited Oct 05 '14 at 01:19

gkrls

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answered Oct 05 '14 at 00:35

user3573644

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How do I define methods in a Mongoose model?

4 Answers4

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