mongoose custom validation using 2 fields

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

In mongoose custom validation using 2 fields 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

Just use Mongoose 'validate' middleware so that you can have access to all fields of the collection. You have to keep one thing in mind that you must wrap all the messages of the validation errors in a JavaScript error object while calling the 'next' function for reporting a validation failure. 

ASchema.pre('validate', function(next) {

    if (this.startDate < this.endDate) {

        next(new Error('End Date must be smaller than Start Date'));

    } else {

        next();

    }

});