mongoose-id-validator

Provides a mongoose plugin that can be used to verify that a document which references
other documents by their ID is referring to documents that actually exist.

This plugin works by performing a count query for documents in the relevant collection with the
ID specified in the document being validated. Note that the validation method is only executed if the ID
value has been updated. This helps prevent unnecessary queries when saving a document if the ID has not been changed.

However, please be aware that this will NOT catch any IDs that were valid at the time they were saved but the referenced
document has subsequently been removed. You should have validation logic in your delete/remove code to handle this.

Usage

Install via NPM

$ npm install mongoose-id-validator

Then you can use the plugin on your schemas

``javascript
var idvalidator = require('mongoose-id-validator');

var ManufacturerSchema = new Schema({
name : String
});
var Manufacturer = mongoose.model('Manufacturer', ManufacturerSchema);

var CarSchema = new Schema({
name : String,
manufacturer : {
type: Schema.Types.ObjectId,
ref: 'Manufacturer',
required: true
}
});
CarSchema.plugin(idvalidator);
var Car = mongoose.model('Car', CarSchema);

var ford = new ManufacturerSchema({ name : 'Ford' });

ford.save(function() {
var focus = new Car({ name : 'Focus' });
focus.manufacturer = "50136e40c78c4b9403000001";

focus.validate(function(err) {
//err.errors would contain a validation error for manufacturer with default message

focus.manufacturer = ford;
focus.validate(function(err) {
//err will now be null as validation will pass
});
});
});
`

You may also use declare a optional refConditions method in your schema. For example:
`javascript
var OtherSchema = new Schema({
referencedId : {
type: Schema.Types.ObjectId,
ref: 'RefSchema',
refConditions: {
field1: 123
}
}
});
`

Values of refConditions can also be functions. With this you can dynamically set refConditions.
These functions have access to the context of the schema instance. An example:

`javascript
var OtherSchema = new Schema({
refFieldMustBeTrue: true,
referencedId : {
type: Schema.Types.ObjectId,
ref: 'RefSchema',
refConditions: {
field1: function () {
return this.refFieldMustBeTrue
}
}
}
});
`

The referenceId value in the code above would only pass validation if the object with this ID exists AND had a property
'field1' that has the value 123. If any conditional property does not match then it would not pass validation.

You can also use this plugin to validate an array of ID references. Please note as above that the implementation
runs a single count query to keep the performance impact to a minimum. Hence you will know if there is a
bad ID value in the array of references but not which one it is.

An example of this is below:
`javascript
var idvalidator = require('mongoose-id-validator');

var ColourSchema = new Schema({
name : String
});
var Colour = mongoose.model('Colour', ColourSchema);

var CarSchema = new Schema({
name : String,
colours : [{
type: Schema.Types.ObjectId,
ref: 'Colour'
}]
});
CarSchema.plugin(idvalidator);
var Car = mongoose.model('Car', CarSchema);

var red = new Colour({ name : 'Red' });
var blue = new Colour({ name : 'Blue' });

red.save(function() {
blue.save(function() {
var focus = new Car({ name : 'Focus' });
focus.colours = [red, "50136e40c78c4b9403000001"];

focus.validate(function(err) {
//err.errors would contain a validation error for colours with default message

focus.colours = [red, blue]
focus.validate(function(err) {
//err will now be null as validation will pass
});
});
});
});
`

Options

`javascript
Model.plugin(id-validator, {
/* Custom validation message with {PATH} being replaced
* with the relevant schema path that contains an invalid
* document ID.
*/
message : 'Bad ID value for {PATH}',

/* Optional mongoose connection object to use if you are
* using multiple connections in your application.
*
* Defaults to built-in mongoose connection if not specified.
*/
connection: myConnection

/* Applies to validation of arrays of ID references only. Set
* to true if you sometimes have the same object ID reference
* repeated in an array. If set, the validator will use the
* total of unique ID references instead of total number of array
* entries when checking the database.
*
* Defaults to false
*/
allowDuplicates: true
});
`

You can also instantiate the validator as an object if you wish to control whether it is enabled at runtime, e.g.
for testing.

`javascript
var IdValidator = require('mongoose-id-validator').getConstructor;

var validator = new IdValidator();
schema.plugin(validator.validate.bind(validator));

//Validation active by default. To disable:
validator.disable();

//Re-enable
validator.enable();
``

Tests

To run the tests you need a local MongoDB instance available. Run with:

npm test

Issues

Please use the GitHub issue tracker to raise any problems or feature requests.

If you would like to submit a pull request with any changes you make, please feel free!

Legal

Code is Copyright (C) Campbell Software Solutions 2014 - 2017.

This module is available under terms of the LGPL V3 license. Hence you can use it in other proprietary projects
but any changes to the library should be made available.