DiscardSerial.cs

using OvfgNx.Data;
using OvfgNx.Models;
using System;
using System.ComponentModel.DataAnnotations;
using System.Reflection;

namespace OvfgNx.Validators
{
    /// <summary>
    /// This vaidator checks that the job contains the serial that the user has entered
    /// </summary>
    public class DiscardSerial : ValidationAttribute
    {
        protected override ValidationResult IsValid(object value, ValidationContext validationContext)
        {
            // get the serial and be sure it is an int
            if (value.GetType() != typeof(int))
            {
                return new ValidationResult("This validator can only be used on an integer");
            }
            int serial = (int)value;

            OvfgNxContext context = (OvfgNxContext)validationContext.GetService(typeof(OvfgNxContext));
            var model = validationContext.ObjectInstance;
            Type type = model.GetType();

            // Check JobId property exists
            PropertyInfo prop = type.GetProperty("JobId");
            if (prop == null)
            {
                return new ValidationResult("This validator can only be used on models containing a JobId");
            }

            // Get the JobId
            int jobId = (int)prop.GetValue(model);
            // Get the job
            Job job = context.Job.Find(jobId);
            // Check the job exists
            if (job == null)
            {
                return new ValidationResult($"Cannot find job with the ID of: {job}");
            }

            // Check the value falls within sn1 and sn2 in the job
            if ((serial >= job.SerialNumber1) && (serial <= job.SerialNumber2))
            {
                return ValidationResult.Success;
            }

            return new ValidationResult("Serial Number is outside of Job Serial range");
        }
    }
}

gistfile1.txt

using OvfgNx.Data;
using OvfgNx.Models;
using System;
using System.ComponentModel.DataAnnotations;
using System.Reflection;

namespace OvfgNx.Validators
{
    /// <summary>
    /// This vaidator checks that the job contains the serial that the user has entered
    /// </summary>
    public class DiscardSerial : ValidationAttribute
    {
        protected override ValidationResult IsValid(object value, ValidationContext validationContext)
        {
            // get the serial and be sure it is an int
            if (value.GetType() != typeof(int))
            {
                return new ValidationResult("This validator can only be used on an integer");
            }
            int serial = (int)value;

            OvfgNxContext context = (OvfgNxContext)validationContext.GetService(typeof(OvfgNxContext));
            var model = validationContext.ObjectInstance;
            Type type = model.GetType();

            // Check JobId property exists
            PropertyInfo prop = type.GetProperty("JobId");
            if (prop == null)
            {
                return new ValidationResult("This validator can only be used on models containing a JobId");
            }

            // Get the JobId
            int jobId = (int)prop.GetValue(model);
            // Get the job
            Job job = context.Job.Find(jobId);
            // Check the job exists
            if (job == null)
            {
                return new ValidationResult($"Cannot find job with the ID of: {job}");
            }

            // Check the value falls within sn1 and sn2 in the job
            if ((serial >= job.SerialNumber1) && (serial <= job.SerialNumber2))
            {
                return ValidationResult.Success;
            }

            return new ValidationResult("Serial Number is outside of Job Serial range");
        }
    }
}