Get isModified in validator - node.js

Is there a way to check if a path has been modified in a validator? Do I need to check or do validators only run if the path was changed?
EDIT:
More specifically, I am trying to make sure an author exists before I insert an id:
var BookSchema = new Schema({
title: { type: String, required: true },
authorId: { type: Schema.Types.ObjectId, ref: 'Author' }
});
BookSchema.path('authorId').validate(function(authorId, done) {
Author.getAuthorById(authorId, function(err, author) {
if (err || !author) {
done(false);
} else {
done(true);
}
});
}, 'Invalid author, does not exist');
In this case I only want this to validate if authorId is set or if it changes. Do I need to check if changed in the function or can I assume that this validator only gets called if the authorId changes and is not null/undefined?
This makes it look like I might be able to call isModified, however I don't see that as a function on 'this'.
Mongoose validation only when changed

Yes, validators are only run if the path is changed, and they also only run if they're not undefined. Except the Required validator, which runs in both cases.

Related

How to do field validations in a mongoose schema based on other fields in the same schema?

Let's say we have :
const mealSchema = Schema({
_id: Schema.Types.ObjectId,
title: { type: string, required: true },
sauce: { type: string }
});
How can we make sauce mandatory if title === "Pasta" ?
The validation needs to work on update too.
I know that a workaround would be
Find
update manually
Then save
But the risk is that if I add a new attribute (let's say "price"), I forget to update it manually too in the workaround.
Document validators
Mongoose has several built-in validators.
All SchemaTypes have the built-in required validator. The required validator uses the SchemaType's checkRequired() function to determine if the value satisfies the required validator.
Numbers have min and max validators.
Strings have enum, match, minlength, and maxlength validators.
For your case you could do something like this
const mealSchema = Schema({
_id: Schema.Types.ObjectId,
title: { type: string, required: true },
sauce: {
type: string,
required: function() {
return this.title === "pasta"? true:false ;
}
}
});
If the built-in validators aren't enough, you can define custom validators to suit your needs.
Custom validation is declared by passing a validation function. You can find detailed instructions on how to do this in the SchemaType#validate().
Update Validators
this refers to the document being validated when using document validation. However, when running update validators, the document being updated may not be in the server's memory, so by default the value of this is not defined. So, What's the solution?
The context option lets you set the value of this in update validators to the underlying query.
In your case, we can do something like this:
const mealSchema = Schema({
_id: Schema.Types.ObjectId,
title: { type: string, required: true },
sauce: { type: string, required: true }
});
mealSchema.path('sauce').validate(function(value) {
// When running update validators with
// the `context` option set to 'query',
// `this` refers to the query object.
if (this.getUpdate().$set.title==="pasta") {
return true
}else{
return false;
}
});
const meal = db.model('Meal', mealSchema);
const update = { title:'pasta', sauce:false};
// Note the context option
const opts = { runValidators: true, context: 'query' };
meal.updateOne({}, update, opts, function(error) { assert.ok(error.errors['title']); });
Not sure if this answers your question. Hope this adds some value to your final solution.
Haven't tested it, pls suggest an edit if this solution needs an upgrade.
Hope this helps.

Prevent field modification with Mongoose Schema

Is there any way to set a field with an "unmodifiable" setting (Such as type, required, etc.) when you define a new Mongoose Schema? This means that once a new document is created, this field can't be changed.
For example, something like this:
var userSchema = new mongoose.Schema({
username: {
type: String,
required: true,
unmodifiable: true
}
})
From version 5.6.0 of Mongoose, we can use immutable: true in schemas (exactly as the aforementioned answer on mongoose-immutable package). Typical use case is for timestamps, but in your case, with username it goes like this:
const userSchema = new mongoose.Schema({
username: {
type: String,
required: true,
immutable: true
}
});
If you try to update the field, modification will be ignored by Mongoose.
Going a little further than what have been asked by OP, now with Mongoose 5.7.0 we can conditionally set the immutable property.
const userSchema = new mongoose.Schema({
username: {
type: String,
required: true,
immutable: doc => doc.role !== 'ADMIN'
},
role: {
type: String,
default: 'USER',
enum: ['USER', 'MODERATOR', 'ADMIN'],
immutable: true
}
});
Sources: What's New in Mongoose 5.6.0: Immutable Properties and What's New in Mongoose 5.7: Conditional Immutability, Faster Document Arrays.
Please be aware that the documentation explicitly states that when using functions with update in their identifier/name, the 'pre' middleware is not triggered:
Although values are casted to their appropriate types when using update, the following are not applied:
- defaults
- setters
- validators
- middleware
If you need those features, use the traditional approach of first retrieving the document.
Model.findOne({ name: 'borne' }, function (err, doc) {
if (err) ..
doc.name = 'jason bourne';
doc.save(callback);
})
Therefore either go with the above way by mongooseAPI, which can trigger middleware (like 'pre' in desoares answer) or triggers your own validators e.g.:
const theOneAndOnlyName = 'Master Splinter';
const UserSchema = new mongoose.Schema({
username: {
type: String,
required: true,
default: theOneAndOnlyName
validate: {
validator: value => {
if(value != theOneAndOnlyName) {
return Promise.reject('{{PATH}} do not specify this field, it will be set automatically');
// message can be checked at error.errors['username'].reason
}
return true;
},
message: '{{PATH}} do not specify this field, it will be set automatically'
}
}
});
or always call any update functions (e.g. 'findByIdAndUpdate' and friends) with an additional 'options' argument in the form of { runValidators: true } e.g.:
const splinter = new User({ username: undefined });
User.findByIdAndUpdate(splinter._id, { username: 'Shredder' }, { runValidators: true })
.then(() => User.findById(splinter._id))
.then(user => {
assert(user.username === 'Shredder');
done();
})
.catch(error => console.log(error.errors['username'].reason));
You can also use the validator function in a non-standard way i.e.:
...
validator: function(value) {
if(value != theOneAndOnlyName) {
this.username = theOneAndOnlyName;
}
return true;
}
...
This does not throw a 'ValidationError' but quietly overrides the specified value. It still only does so, when using save() or update functions with specified validation option argument.
I had the same problem with field modifications.
Try https://www.npmjs.com/package/mongoose-immutable-plugin
The plugin will reject each modification-attempt on a field and it works for
Update
UpdateOne
FindOneAndUpdate
UpdateMany
Re-save
It supports array, nesting objects, etc. types of field and guards deep immutability.
Plugin also handles update-options as $set, $inc, etc.
You can do it with Mongoose only, in userSchema.pre save:
if (this.isModified('modified query')) {
return next(new Error('Trying to modify restricted data'));
}
return next();
You can use Mongoose Immutable. It's a small package you can install with the command below, it allows you to use the "immutable" property.
npm install mongoose-immutable --save
then to use it:
var userSchema = new mongoose.Schema({
username: {
type: String,
required: true,
immutable: true
}
});
userSchema.plugin(immutablePlugin);

How to cancel a mongoose query in a 'pre' hook

I am implementing some kind of caching for my 'find' queries on a certain schemas, and my cache works with the pre\post query hooks.
The question is how can I cancel the 'find' query correctly?
mySchema.pre('find', function(next){
var result = cache.Get();
if(result){
//cancel query if we have a result from cache
abort();
} else {
next();
}
});
so that this promise will be fulfilled?
Model.find({..})
.select('...')
.then(function (result) {
//We can reach here and work with the cached results
});
I was unable to find a reasonable solution to this myself for another non-caching reason but if your own specific caching method isn't too important I'd recommend you look at mongoose-cache, works well and has simple settings thanks to it's dependency: node-lru-cache, check that out for more options.
you may want to check out mongoose validators, that seems like a better way to handle controlling whether or not an object gets created.
You can create a custom validate function that will throw an error in the Model.save function, causing it to fail. Here is a code snippet from the docs:
// make sure every value is equal to "something"
function validator (val) {
return val == 'something';
}
new Schema({ name: { type: String, validate: validator }});
// with a custom error message
var custom = [validator, 'Uh oh, {PATH} does not equal "something".']
new Schema({ name: { type: String, validate: custom }});
// adding many validators at a time
var many = [
{ validator: validator, msg: 'uh oh' }
, { validator: anotherValidator, msg: 'failed' }
]
new Schema({ name: { type: String, validate: many }});
// or utilizing SchemaType methods directly:
var schema = new Schema({ name: 'string' });
schema.path('name').validate(validator, 'validation of {PATH} failed with value {VALUE}');
Found that here if you want to look into it more. Hope that helps someone!
http://mongoosejs.com/docs/api.html#schematype_SchemaType-validate

Skip or Disable validation for mongoose model save() call

I'm looking to create a new Document that is saved to the MongoDB regardless of if it is valid. I just want to temporarily skip mongoose validation upon the model save call.
In my case of CSV import, some required fields are not included in the CSV file, especially the reference fields to the other document. Then, the mongoose validation required check is not passed for the following example:
var product = mongoose.model("Product", Schema({
name: {
type: String,
required: true
},
price: {
type: Number,
required: true,
default: 0
},
supplier: {
type: Schema.Types.ObjectId,
ref: "Supplier",
required: true,
default: {}
}
}));
var data = {
name: 'Test',
price: 99
}; // this may be array of documents either
product(data).save(function(err) {
if (err) throw err;
});
Is it possible to let Mongoose know to not execute validation in the save() call?
[Edit]
I alternatively tried Model.create(), but it invokes the validation process too.
This is supported since v4.4.2:
doc.save({ validateBeforeSave: false });
Though there may be a way to disable validation that I am not aware of one of your options is to use methods that do not use middleware (and hence no validation). One of these is insert which accesses the Mongo driver directly.
Product.collection.insert({
item: "ABC1",
details: {
model: "14Q3",
manufacturer: "XYZ Company"
},
}, function(err, doc) {
console.log(err);
console.log(doc);
});
You can have multiple models that use the same collection, so create a second model without the required field constraints for use with CSV import:
var rawProduct = mongoose.model("RawProduct", Schema({
name: String,
price: Number
}), 'products');
The third parameter to model provides an explicit collection name, allowing you to have this model also use the products collection.
I was able to ignore validation and preserve the middleware behavior by replacing the validate method:
schema.method('saveWithoutValidation', function(next) {
var defaultValidate = this.validate;
this.validate = function(next) {next();};
var self = this;
this.save(function(err, doc, numberAffected) {
self.validate = defaultValidate;
next(err, doc, numberAffected);
});
});
I've tested it only with mongoose 3.8.23
schema config validateBeforeSave=false
use validate methed
// define
var GiftSchema = new mongoose.Schema({
name: {type: String, required: true},
image: {type: String}
},{validateBeforeSave:false});
// use
var it new Gift({...});
it.validate(function(err){
if (err) next(err)
else it.save(function (err, model) {
...
});
})

mongoose doc.save fails without error in schema method

Using mongoose i am doing:
var postSchecma = mongoose.Schema({
title: String,
body: String,
link: String,
voting: {
has: {
type: Boolean,
default:
false
},
canVoteFor: [mongoose.Schema.Types.Mixed],
votedFor:{},
voteDates:{}
},
comments: [mongoose.Schema.Types.Mixed],
date: {
type: mongoose.Schema.Types.Mixed,
default:
new Date().getTime()
}
}, {
strict: false,
safe:true
})
and
postSchecma.methods.vote = function(voteFor, callback) {
var self = this;
if(self.voting.canVoteFor.indexOf(voteFor) < 0) {
callback(new Error('Error: Invalid Thing To Vote For'));
return;
}
this.voting.voteDates[voteFor].push(new Date().getTime())
this.voting.votedFor[voteFor]++
s = this;
this.save(function(err) {
if(err) {
callback(err)
}
console.log(err);
console.log("this:"+ s);
callback(s)
})
}
in postSchecma.methods.vote the value of this.voting.votedFor[voteFor] is correct. but when I query the db it is the old value. if it helps i am using the db in 2 files and the methods may not be exact duplicates.
I also know it is something with mongoose because I can change the record to a different value with a mongoDB GUI and it works fine.
let me know if you need any more info,
thanks,
Porad
Any field in your schema that's defined as {} or Mixed must be explicitly marked as modified or Mongoose won't know that it has changed and that Mongoose needs to save it.
In this case you'd need to add the following prior to the save:
this.markModified('voting.voteDates');
this.markModified('voting.votedFor');
See docs on Mixed here.
Turns out that this also sometimes applies for non-Mixed items, as I painfully discovered. If you reassign an entire sub-object, you need to use markModified there as well. At least... sometimes. I didn't use to get this error, and then I did, without changing any relevant code. My guess is that it was a mongoose version upgrade.
Example! Say you have...
personSchema = mongoose.Schema({
name: {
first: String,
last: String
}
});
...and then you call...
Person.findById('whatever', function (err, person) {
person.name = {first: 'Malcolm', last: 'Ocean'};
person.save(function (err2) {
// person.name will be as it was set, but this won't persist
// to the database
});
});
...you will have a bad time unless you call person.markModified('name') before save
(or alternatively, call both person.markModified('name.first') and person.markModified('name.last') ...but that seems clearly inferior here)

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