CODEWITHSUNDEEP
c#asp.net-mvcasp.net-core
jgrewal
jgrewal

Reputation: 342

query a list and compare Id's to logged in userId

I have a list model being passed into my view. But I want to separate the Participant's inside the list depending on which User is logged in on the ViewBag.

how I'm saving the logged in user to ViewBag from controller:

        HttpContext.Session.SetInt32("UserId", dbUser.UserId);
        ViewBag.UserId = HttpContext.Session.GetInt32("UserId");

current view code:

@model List<League>
    @{    
        if (Model != null && Model.Any())
        {
            foreach(League i in Model)
            {
                foreach (MMLeagueParticipant mmLeagueParticipant in i.allParticipants)
                {
                    <p>@mmLeagueParticipant.child.ParticipantFirstName @mmLeagueParticipant.child.ParticipantLastName</p>
                }  
            }
        }
        else
        {
            <p>the list is empty</p>
        }
    }

my code currently works but it is displaying all the Participant's regardless of if they belong the to current logged in User or not.

Solution I thought that might work:

<p>Your kids:</p>
foreach(League i in Model)
{
    foreach (MMLeagueParticipant mmLeagueParticipant in i.allParticipants)
    {
        if(mmLeagueParticipant.child.Parent.UserId == ViewBag.UserId )
        {
            <p>@mmLeagueParticipant.child.ParticipantFirstName @mmLeagueParticipant.child.ParticipantLastName</p>
        }
    }
}
<p>All other kids:</p>
foreach(League i in Model)
{
    foreach (MMLeagueParticipant mmLeagueParticipant in i.allParticipants)
    {
        if(mmLeagueParticipant.child.Parent.UserId != ViewBag.UserId )
        {
            <p>@mmLeagueParticipant.child.ParticipantFirstName @mmLeagueParticipant.child.ParticipantLastName</p>
        }

    }
}

The error I get from trying this:

NullReferenceException: Object reference not set to an instance of an object.

it doesn't like the if(mmLeagueParticipant.child.Parent.UserId == ViewBag.UserId) line.

Models relations:

My league model:

int LeagueId { get; set; }
string sport { get; set; }
string gender { get; set; }
string ageRange { get; set; }

​List<MMLeagueParticipant> allParticipants  { get; set; }

My ViewModel model:

public List<Participant> allParticipants { get; set; }
public ViewModel.Participant participant { get; set; }

public class Participant
{
int ParticipantId { get; set; }
string ParticipantFirstName { get; set; }
string ParticipantLastName { get; set; }
string ParticipantGender { get; set; }
System.DateTime ParticipantDOB { get; set; }

List<MMLeagueParticipant> allLeagues { get; set; }

int UserId { get; set; }
User Parent { get; set; }
}

My MMLeagueParticipant middle table for the league model and ViewModel.Participant:

int MMLeaugeParticipantId { get; set; }
int ParticipantId { get; set; }
int LeaugeId { get; set; }
leauge sport { get; set; }

ViewModel.Participant child { get; set; }

My User model:

int UserId { get; set; }
string FirstName { get; set; }
string LastName { get; set; }
string Email { get; set; }
string Password { get; set; }
strig ConfirmPassword { get; set; }

List<ViewModel.Participant> kids { get; set; }

Upvotes: 1

Views: 239

Answers (1)

fiji3300
fiji3300

Reputation: 103

You can simply filter your participants with

var userParticipants = allParticipants.Where(p => p.UserId == Viewbag.UserId).ToList()

It requires you to use the System.Linq namespace.

Edit: Here's a more specific example

foreach(League i in Model)
            {
                var userParticipants = i.allParticipants.Where(p => p.UserId == Viewbag.UserId).ToList();
                foreach (MMLeagueParticipant mmLeagueParticipant in userParticipants)
                {
                    <p>@mmLeagueParticipant.child.ParticipantFirstName @mmLeagueParticipant.child.ParticipantLastName</p>
                }  
            }

Upvotes: 2

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