Populate Kendo DropDownList Dynamically Using ASP.Net Web API

Gowtham K
Jun 03, 2015
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Create an empty Web API and integrate with Entity Framework as I explained in my previous article CRUD Opertaion in Kendo Grid using Web API.

Objective of this article

Insert a record into a SQL Server database table and populate the records in a Kendo Dropdown list dynamically by reading the record from a SQL Server database table using the ASP.NET Web API REST full service.

Create a REST full service to Insert a Record in SQL Table.

Open the existing ASP.NET MVC 4 project that we created earlier (refer to the article CRUD Opertaion in Kendo Grid using Web API).

Right-click on the project root and add a new HTML page. I named it KendoDropDown.html.

Finally the project structure will be as in Figure 1.

Figure 1: Controller

Open the CategoryController class now, for this application we will use the following GET and POST services.

public IEnumerable<Category> GetCategories()
{
return db.Categories.AsEnumerable();
}
public HttpResponseMessage PostCategory(Category category)
{
if (ModelState.IsValid)
{
db.Categories.Add(category);
db.SaveChanges();
HttpResponseMessage response = Request.CreateResponse(HttpStatusCode.Created, category);
response.Headers.Location = new Uri(Url.Link("DefaultApi", new { id = category.CategoryID }));
return response;
}
else
{
return Request.CreateErrorResponse(HttpStatusCode.BadRequest, ModelState);
}
}

Check the response in Postman/Fiddler.

1. The HTTP GET response/request is as in Figure 2.

Figure 2: HTTP GET response/request

2. The HTTP POST response/request is as in Figure 3.

Figure 3: HTTP Post

Consuming the REST full services using Kendo UI.

Write the following design in the new HTML page of the project.

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<link rel="stylesheet" href="http://cdn.kendostatic.com/2014.3.1316/styles/kendo.common.min.css" />
<link rel="stylesheet" href="http://cdn.kendostatic.com/2014.3.1316/styles/kendo.default.min.css" />
<link rel="stylesheet" href="http://cdn.kendostatic.com/2014.3.1316/styles/kendo.dataviz.min.css" />
<link rel="stylesheet" href="http://cdn.kendostatic.com/2014.3.1316/styles/kendo.dataviz.default.min.css" />
<script src="http://cdn.kendostatic.com/2014.3.1316/js/jquery.min.js"></script>
<script src="http://cdn.kendostatic.com/2014.3.1316/js/kendo.all.min.js"></script>
<title></title>
</head>
<body>
<div id="example">
<div class="demo-section k-header">
<input id="Category" style="width: 400px;" />
</div>
<br />
<div id="Category-display" class="demo-section k-header"></div>
</div>
<script id="Category_template" type="text/x-kendo-template">
<h4>Category: #: CategoryName #</h4>
<div class="form-group" id="Category">
<div class="col-lg-12 bg">
<div class="col-lg-6">
<div class="form-inline">
<span>Category:</span>
</div>
<div class="form-inline">
<input required validationmessage="Please enter the Category" type="text" id="Category_name" name="Category" data-bind="value:category" class="form-control" placeholder="Category...." />
<span class="k-invalid-msg" data-for="Category"></span>
</div>
<div class="form-inline">
<button id="submit_btn" onclick="InsertCategory()" class="k-button">Submit</button>
</div>
</div>
</div>
</div>
</script>
<script>
var template = kendo.template($("#Category_template").html());
function preview() {
var dropdown = $("#Category").data("kendoDropDownList");
var product = dropdown.dataSource.get(dropdown.value());
var productPreviewHtml = template(product);
$("#Category-display").html(productPreviewHtml);
}
$("#Category").kendoDropDownList({
dataTextField: "CategoryName",
dataValueField: "CategoryID",
dataSource: {
transport: {
read: {
url: "http://localhost:54129/api/Category",
dataType: "json"
}
},
schema: {
model: {
id: "CategoryID"
}
}
},
dataBound: preview,
change: preview
});
</script>
<script>
function InsertCategory() {
alert("hai");
$.ajax(
{
cache: false,
async: false,
type: "POST",
url: "http://localhost:54129/api/Category",
data:
{
CategoryName: $("#Category_name").val(),
},
success: function (data) {
alert(data);
},
});
};
</script>
</body>
</html>