schema mongoose Required field if otherfield is true [duplicate] - node.js

Question

I want to use mongoose custom validation to validate if endDate is greater than startDate. How can I access startDate value? When using this.startDate, it doesn't work; I get undefined.
var a = new Schema({
startDate: Date,
endDate: Date
});
var A = mongoose.model('A', a);
A.schema.path('endDate').validate(function (value) {
return diff(this.startDate, value) >= 0;
}, 'End Date must be greater than Start Date');
diff is a function that compares two dates.

Answer 1

You can do that using Mongoose 'validate' middleware so that you have access to all fields:
ASchema.pre('validate', function(next) {
if (this.startDate > this.endDate) {
next(new Error('End Date must be greater than Start Date'));
} else {
next();
}
});
Note that you must wrap your validation error message in a JavaScript Error object when calling next to report a validation failure.

Answer 2

An an alternative to the accepted answer for the original question is:
var mongoose = require('mongoose'),
Schema = mongoose.Schema;
// schema definition
var ASchema = new Schema({
startDate: {
type: Date,
required: true
},
endDate: {
type: Date,
required: true,
validate: [dateValidator, 'Start Date must be less than End Date']
}
});
// function that validate the startDate and endDate
function dateValidator(value) {
// `this` is the mongoose document
return this.startDate <= value;
}

Answer 3

I wanted to expand upon the solid answer from #JohnnyHK (thank you) by tapping into this.invalidate:
Schema.pre('validate', function (next) {
if (this.startDate > this.endDate) {
this.invalidate('startDate', 'Start date must be less than end date.', this.startDate);
}
next();
});
This keeps all of the validation errors inside of a mongoose.Error.ValidationError error. Helps to keep error handlers standardized. Hope this helps.

Answer 4

You could try nesting your date stamps in a parent object and then validate the parent. For example something like:
//create a simple object defining your dates
var dateStampSchema = {
startDate: {type:Date},
endDate: {type:Date}
};
//validation function
function checkDates(value) {
return value.endDate < value.startDate;
}
//now pass in the dateStampSchema object as the type for a schema field
var schema = new Schema({
dateInfo: {type:dateStampSchema, validate:checkDates}
});

Answer 5

Using 'this' within the validator works for me - in this case when checking the uniqueness of email address I need to access the id of the current object so that I can exclude it from the count:
var userSchema = new mongoose.Schema({
id: String,
name: { type: String, required: true},
email: {
type: String,
index: {
unique: true, dropDups: true
},
validate: [
{ validator: validator.isEmail, msg: 'invalid email address'},
{ validator: isEmailUnique, msg: 'Email already exists'}
]},
facebookId: String,
googleId: String,
admin: Boolean
});
function isEmailUnique(value, done) {
if (value) {
mongoose.models['users'].count({ _id: {'$ne': this._id }, email: value }, function (err, count) {
if (err) {
return done(err);
}
// If `count` is greater than zero, "invalidate"
done(!count);
});
}
}

Answer 6

This is the solution I used (thanks to #shakinfree for the hint) :
var mongoose = require('mongoose'),
Schema = mongoose.Schema;
// schema definition
var ASchema = new Schema({
dateSchema : {
type:{
startDate:{type:Date, required: true},
endDate:{type:Date, required: true}
},
required: true,
validate: [dateValidator, 'Start Date must be less than End Date']
}
});
// function that validate the startDate and endDate
function dateValidator (value) {
return value.startDate <= value.endDate;
}
module.exports = mongoose.model('A', ASchema);