asp.net core getting data from json and jquerry

C# Corner

Marius Vasile

5y743.NET

I have two select and I want to populate the second but I don't know what am I doing wrong

class="col-md-10 mb-2">
"IRSelect" class="form-control ml-1">
"">--Select Filtering Condition--
"1">Issuer
"2">Receiver

class="col-md-10">

"IRDetail" class="form-control ml-1" asp-items="@(new SelectList(string.Empty, "Issuer", "Issuer"))">

"">--Select Name--

and json

public async Task OnGetIRDetails1Async()
{
var userId = User.FindFirstValue(ClaimTypes.NameIdentifier);
var orgid = await _context.UsersData.Where(s => s.Id == userId).Select(s => s.OrgID).FirstOrDefaultAsync();
var todayYear = DateTime.Today.Year;
var valIR = await _context.PTWContents.Where(s => s.OrgID == orgid && s.StartDate.Year == todayYear).Select(s =>
new SelectListItem
{
Value = s.Issuer,
Text = s.Issuer
}).ToListAsync();
return new JsonResult(new SelectList(valIR , "Issuer", "Issuer"));
}
public async Task OnGetIRDetails2Async()
{
var userId = User.FindFirstValue(ClaimTypes.NameIdentifier);
var orgid = await _context.UsersData.Where(s => s.Id == userId).Select(s => s.OrgID).FirstOrDefaultAsync();
var todayYear = DateTime.Today.Year;
var valIR = await _context.PTWContents.Where(s => s.OrgID == orgid && s.StartDate.Year == todayYear).Select(s =>
new SelectListItem
{
Value = s.Receiver,
Text = s.Receiver
}).ToListAsync();
return new JsonResult(new SelectList(valIR , "Receiver", "Receiver"));
}

and jquery

$(function () {
$("#IRSelect").on("change", function () {
var categoryId = $(this).val();
if (categoryId = 1) {
$("#IRDetail").empty();
$("#IRDetail").append("--Select Name--");
$.getJSON(`?handler=IRDetails1`, (data) => {
$.each(data, function (i, item) {
$("#IRDetail").append(`"${item.value}"> ${item.text}`);
});
});
}
if (categoryId = 2) {
$("#IRDetail").empty();
$("#IRDetail").append("--Select Name--");
$.getJSON(`?handler=IRDetails2`, (data) => {
$.each(data, function (i, item) {
$("#IRDetail").append(`"${item.value}"> ${item.text}`);
});
});
}
});
});

3 Replies

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Marius Vasile5y ago
Ok, I got it work with

Json
public async Task OnGetIRDetails1Async()
        {
            var userId = User.FindFirstValue(ClaimTypes.NameIdentifier);
            var orgid = await _context.UsersData.Where(s => s.Id == userId).Select(s => s.OrgID).FirstOrDefaultAsync();
            var todayYear = DateTime.Today.Year;

            var valIR = await (from a in _context.PTWContents.Where(s => s.OrgID == orgid && s.StartDate.Year == todayYear)
                               select a.Issuer).Distinct().ToListAsync();

            return new JsonResult(new SelectList(valIR, "Issuer"));
        }
and javascript
"text/javascript">
        $(function () {
            $("#IRSelect").on("change", function () {
                $("#IRDetail").empty();
                $("#IRDetail").append("--Select Name--");
                $.getJSON(`?handler=IRDetails1`, (data) => {
                    $.each(data, function (i, item) {
                        $("#IRDetail").append(`"${item.value}"> ${item.text}`);
                    });
                });

            });
        });
Marius Vasile5y ago
Thank you Jignesh, I already have it implemented in my project, working just fine, but this one is not. I even tried to simplify like below so no matter the value on first dropdownlist, I get the json, the problem is I don't get any values, while the database has values

View
class="col-md-10 mb-2">
                "IRSelect" class="form-control ml-1">
                    "">--Select Filtering Condition--
                    "1">Issuer
                    "2">Receiver
class="col-md-10">
"IRDetail" class="form-control ml-1" asp-items="@(new SelectList(string.Empty, "Issuer", "Issuer"))">
"">--Select Name--

"text/javascript">
$(function () {
$("#IRSelect").on("change", function () {
$("#IRDetail").empty();
$("#IRDetail").append("--Select Name--");
$.getJSON(`?handler=IRDetails1`, (data) => {
$.each(data, function (i, item) {
$("#IRDetail").append(`"${item.value}"> ${item.text}`);
});
});
});
});

json

public async Task OnGetIRDetails1Async()
{
var userId = User.FindFirstValue(ClaimTypes.NameIdentifier);
var orgid = await _context.UsersData.Where(s => s.Id == userId).Select(s => s.OrgID).FirstOrDefaultAsync();
var todayYear = DateTime.Today.Year;
var valIR = await _context.PTWContents.Where(s => s.OrgID == orgid && s.StartDate.Year == todayYear).Select(s =>
new SelectListItem
{
Value = s.Issuer.ToString(),
Text = s.Issuer
}).ToListAsync();
return new JsonResult(new SelectList(valIR, "Issuer", "Issuer"));
}

Jignesh Kumar5y ago
Hi Marius,

Please refer this article which will help you,
https://www.c-sharpcorner.com/article/creating-simple-cascading-dropdownlist-in-asp-net-core-mvc-with-new-tag-helpers/#:~:text=For%20adding%20model%2C%20just%20right,click%20on%20the%20Add%20button.