Passing data from View to Controller and back to the same View ASP Net Core MVC

Question

Hi I got no idea how pass simple data from View to Controller which I need to generate values for update the same View, let me show code for better understanding. I want add Visit which contains Patient, Doctor and date of visit (day and hour) so in Create page I got code :

<form asp-action="Create">
        <div asp-validation-summary="ModelOnly" class="text-danger"></div>
        <div class="form-group">
            <label asp-for="PatientId" class="control-label"></label>
            <select asp-for="PatientId" class="form-control" asp-items="ViewBag.PatientId"></select>
        </div>
        <div class="form-group">
            <label asp-for="DoctorId" class="control-label"></label>
            <select asp-for="DoctorId" id="iddoctor" class="form-control" asp-items="ViewBag.DoctorId" onchange="go()">
            </select>
        </div>
       <div class="form-group">
           <label asp-for="date" class="control-label"></label>
           <input asp-for="date" class="form-control" />
           <span asp-validation-for="date" class="text-danger"></span>
       </div>
       <div class="form-group">
    <label asp-for="date" class="control-label"></label>
    <select asp-for="date" class="form-control" asp-items="ViewBag.date"></select>
</div>

I select patient, doctor and date from calendar and I want send it to Controller which should generate list of avaiable hours to put in the same page in ViewBag.date so I can select also hour and finish adding visit by click "add visit"

My Controller Create function

public IActionResult Create()
    {
     ViewData["DoctorId"] = new SelectList(_context.Doctors, "DoctorId", "Surname" );
     ViewData["PatientId"] = new SelectList(_context.Patients, "PatientId", "Surname" );
     return View();
    }

EDIT : Solution in my answer below

Answer 1

I select patient, doctor and date from calendar and I want send it to Controller which should generate list of avaiable hours to put in the same page in ViewBag.date so I can select also hour and finish adding visit by click "add visit"

To achieve the requirement, you can try to define a new property for hour info, like below.

public class VisitViewModel
{
    public int PatientId { get; set; }
    public int DoctorId { get; set; }
    [DataType(DataType.Date)]
    public DateTime date { get; set; }
    public string hour { get; set; }
}

Update View code to bind hour field

@model VisitViewModel
@{
    ViewData["Title"] = "Create";
}

<h1>Create</h1>

<form asp-action="Create">
    <div asp-validation-summary="ModelOnly" class="text-danger"></div>
    <div class="form-group">
        <label asp-for="PatientId" class="control-label"></label>
        <select asp-for="PatientId" class="form-control" asp-items="ViewBag.PatientId"></select>
    </div>
    <div class="form-group">
        <label asp-for="DoctorId" class="control-label"></label>
        <select asp-for="DoctorId" id="iddoctor" class="form-control" asp-items="ViewBag.DoctorId" onchange="go()">
        </select>
    </div>
    <div class="form-group">
        <label asp-for="date" class="control-label"></label>
        <input asp-for="date" class="form-control" />
        <span asp-validation-for="date" class="text-danger"></span>
    </div>
    <div class="form-group">
        <label asp-for="hour" class="control-label"></label>
        <select asp-for="hour" class="form-control" asp-items="ViewBag.date"></select>
    </div>
    <input type="submit" value="Create" />
</form>

In action method, generate new datetime based on selected day and hour.

public IActionResult Create(VisitViewModel visit)
{
    var date = visit.date.ToShortDateString();

    var newdate = Convert.ToDateTime(date + " " + visit.hour);

    //...

    //code logic

    //...

Test Result

Answer 2

Ok I found solution by myself. I replaced last div in my View for this one :

            <div class="form-group">
                <label asp-for="hour" class="control-label"></label>
                <select asp-for="hour" class="form-control" asp-items="ViewBag.hour"> 
                 </select>
            </div> 

Next I added function "goes" to on change event to Doctor list and calendar

 <select asp-for="DoctorId" id="iddoctor" class="form-control" onchange= "goes()" asp- 
 items="ViewBag.DoctorId">

In goes() function there is code :

 $.ajax({
                  url: '@Url.Action("Updatedata", "Visits")',
                        dataType: "json",
                        data: { x, data: y} ,
                        success: function (data) {
                          var items = data;
                          var item = "";
                          var itemss
                          for (var i = 0; i < items.length; i++) {
                              item = items[i];
                              item = item.replace("0001-01-01T", "").slice(0, -3);
                              itemss += "<option value='" + item + "'>" + item + " 
                              </option>"
                              }
                             $('#hour').html(itemss);},});}};

where I'm sending selected doctor id and selected date to function "updatedata" in VisitsController, which returns me list of available hours. I hope someone will find this solution useful.