How to create custom validation for a model that includes list<T>

Question

1.00/5 (1 vote)

See more:

public class Parameter
{
  public int Id {get;set;}
  public string name {get;set;}
  public List<Phonenumbers> number {get;set;}
}

public class Phonenumbers
{
  public string number1 {get;set;}
  public string number2 {get;set;}
}


public Task<bool> Content(Parameter par)
{
  if(string.IsNullOrWhiteSpace(par.Id).ToString()))
    {
      //Todo
    }
 if(string.IsNullOrWhiteSpace(par.name))
    {
      //Todo 
    }
   
//I want to also validate List contents (number1,number2) fields if IsNullOrWhiteSpace
}

What I have tried:

<pre>

public class Parameter
{
  public int Id {get;set;}
  public string name {get;set;}
  public List<Phonenumbers> number {get;set}
}

public class Phonenumbers
{
  public string number1 {get;set;}
  public string number2 {get;set;}
}


public Task<bool> Content(Parameter par)
{
  if(string.IsNullOrWhiteSpace(par.Id).ToString()))
    {
      //Todo
    }
 if(string.IsNullOrWhiteSpace(par.name))
    {
      //Todo 
    }
 if(string.IsNullOrWhiteSpace(par.Phonenumbers.Any(x => x.number1== null).ToString()))
    {
      //Todo 
    }
}

Posted 23-Jul-18 5:30am

wizklaus

Updated 23-Jul-18 6:08am

Add a Solution

2 solutions

Solution 2

There is no point in converting the Id field from int to string - it will default to 0 if you don't set it. Therefore you should just check that it is within a valid range (e.g. greater than 0).

You need to check that the par object is not null before attempted to access the numbers property. Otherwise you will get a Null Reference Exception when the object is null.
Also if the count of numbers is 0 then it will not find any phone numbers.

// Int will always be populated (it defaults to 0 if you don't set it).
if (par.Id <= 0)
{
    Console.WriteLine("1");
}
if (string.IsNullOrWhiteSpace(par.name))
{
    Console.WriteLine("2");
}
if (par.number == null ||
    par.number.Count == 0 ||
    par.number.Any(x => x.number1 != null || x.number2 != null)
    )
{
    Console.WriteLine("3");
}

Posted 23-Jul-18 6:08am

WiganLatics

Updated 23-Jul-18 6:15am

v2

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Simon_Whale · Accepted Answer · 2018-07-23T05:59:00

I would change your code here slightly. I have changed the return type here to just a bool as I am not sure what the Task<bool> is doing here

C#

public bool Content(Parameter par)
{
  if(par != null)
  {
    //int can not be null but it can have a default number
    //so test for that, unless the type is int? then you can 
    //test for null directly
    if(par.Id != 0)
    {
       //Todo
    }

    if(String.IsNullOrWhileSpave(par.name))
    {
      //Todo
    }

    if(par.Phonenumbers != null)
    {
      var failed = par.Phonenumbers.Count(p=> String.IsNullOrEmpty(p.number1) || String.IsNullOrEmpty(p.number2));
      if(failed > 0) 
      {
        //todo
      }
    }
  }
}