asp.net core show sublist if data exists

Question

I am trying to display a sublist on a button click if data exists, if not to redirect to another page. What I did   View page   @ foreach  (var a  in  Model.WOForms)           {                class = "row no-gutters mt-2 ml-2" >                    class = "col-md-1" >                       @ if  (Model.WOS ==  true )                       {                            "submit"   class = "form-control btn-link"  asp-page-handler= "WOForm"  asp-route-id= "@a.WONumber"  value= "@Html.DisplayFor(modelItem => a.WONumber)"  />                       }                       @ if  (Model.WOS ==  false )                       {                            "button"   class = "col-sm-12 btn btn-link font-weight-bold"  style= "border-color:firebrick; background-color:lightgray; color:firebrick"  data-toggle= "collapse"  data-target= "#Subsequent"  aria-expanded= "false"  aria-controls= "Subsequent" >@Html.DisplayFor(modelItem => a.WONumber)                        }                                        class = "col-md-2 ml-1" >                        class = "form-control" >@Html.DisplayFor(modelItem => a.AssetName)                                         class = "col-md-2 ml-1" >                        class = "form-control" >@Html.DisplayFor(modelItem => a.EquipmentName)                                         class = "col-md-2 ml-1" >                        class = "form-control" >@Html.DisplayFor(modelItem => a.ComponentName)                                         class = "col-md-3 ml-1" >                        class = "form-control" >@Html.DisplayFor(modelItem => a.Deficiency)                                         class = "col-md-1 ml-1" >                        class = "form-control" >@Html.DisplayFor(modelItem => a.WOStatus)                                                     "Subsequent"   class = "collapse" >                    class = "col-sm-12 row no-gutters pl-5" >                       @ foreach  (var b  in  Model.WOSubsequents)                       {                            class = "col-md-1 ml-1" >                                "submit"   class = "form-control btn-link"  asp-page-handler= "WOForm"  asp-route-id= "@a.WONumber"  value= "@Html.DisplayFor(modelItem => a.WONumber) - @Html.DisplayFor(modelItem => b.WONumberS)"  />                                                        class = "col-md-2 ml-1" >                                class = "form-control" >@Html.DisplayFor(modelItem => a.AssetName)                                                         class = "col-md-2 ml-1" >                                class = "form-control" >@Html.DisplayFor(modelItem => a.EquipmentName)                                                         class = "col-md-2 ml-1" >                                class = "form-control" >@Html.DisplayFor(modelItem => a.ComponentName)                                                         class = "col-md-3 ml-1" >                                class = "form-control" >@Html.DisplayFor(modelItem => a.Deficiency)                                                         class = "col-md-1 ml-1" >                                class = "form-control" >@Html.DisplayFor(modelItem => a.WOStatus)                                                    }                                                  }   cshtml   WOForms = await (from a  in  _context.WOMains.Where(a => a.OrgID == orgid)                               join b  in  _context.WOInitiators on a.WOMainID equals b.WOMainID into Temp1                               from c  in  Temp1                                  select  new  WOForm                               {                                                                      WONumber = a.WONumber,                                    //other fields                                   }).ToListAsync();                   foreach (var i  in  WOForms)               {                   WOSubsequents = await _context.WOSubsequents.Where(s => s.WONumber == i.WONumber).OrderBy(s =>…

Sachin Singh · Accepted Answer

As first presentation layer logic should be in viewmodel or model , please use razor just for UI not for any calculations second why there are 2 conditions just to achieve samething.
foreach(var i in WOForms)                 {                        class = "col-md-1" >                     @ if  (i.WONumber                  {                          class = "form-control" >TRUE                      }                     else                    {                          class = "form-control" >FALSE                      }                                                       }    }

Marius Vasile · Answer

I don't get the result I want. I will try more, your logic looks correct but I do something wrong I don't see yet

Sachin Singh · Answer

if ( Model.WOSubsequents.Count()==0 ||  Model.WOSubsequents==null)   {   // write the logic here.    }

Marius Vasile · Answer

Now you're talking, thank you Sachin. What is the oposite of Model.WOSubsequents.Count() > 0 ? How do I write the condition if Count is null?

Marius Vasile · Answer

This is getting even strange. I have two WONumbers, one is 82 the other is 107. The foreach loop below is getting the same result. What is happening?   foreach (var i  in  WOForms)               {                    if (i.WONumber                  {                       WOS =  true ;                   }                    if  (i.WONumber > 100)                   {                       WOS =  false ;                   }                                  }   class = "col-md-1" >                   @ if  (Model.WOS ==  true )                   {                        class = "form-control" >TRUE                    }                   @ if  (Model.WOS ==  false )                   {                        class = "form-control" >FALSE                    }

Marius Vasile · Answer

My issue, to try to be more clear, is that if there is subsequent the button should activate the collapse and if not it should redirect. Now, either both redirect or both activate collapse. the logic in    foreach (var i  in  WOForms)               {                   WOSubsequents = await _context.WOSubsequents.Where(s => s.WONumber == i.WONumber).OrderBy(s => s.WONumberS).ToListAsync();                    if  (WOSubsequents.Count() > 0)                   {                       WOS =  false ;                   }                    else                    {                       WOS =  true ;                   }               }   is not effective

Marius Vasile · Answer

Why can't I do this with EF? There is no difference in the content, actually si the same class. I have the connection made in    public   class  WOSubsequent       {           [Key]           [DatabaseGenerated(DatabaseGeneratedOption.Identity)]            public   string  WOSID {  get ;  set ; }            public   int  WONumber {  get ;  set ; }            public   int  WONumberS{  get ;  set ; }       }   and also the class WOMain which has all the data including WONumber, so it should work but I guess is sothing with the EF that I do wrong

Sachin Singh · Answer

your output is exactly what you are telling him to do. your concern is modelNo 82 has subsequent data but 107 doesn't have ?? if this is the case then your class structure should be
public   class  womains   {    all its singleton properties,   public  List  sqs {get;set;}  // where subsequent is a class with its own properties    }
now fill each object of  womains class with subsequent list then it will work as expected.