Dynamically Adding and Removing Form Items
Environment
| Product Version | 2022.2.621 |
| Product | Grid for Progress® Telerik® UI for ASP.NET MVC |
Description
How can I dynamically add and remove items in the Telerik UI for ASP.NET MVC Form?
Solution
This example demonstrates how to add/remove fields dynamically in the "Phones" Form group. The implementation relies on the following key steps:
- Create a 'Add Phone" button and insert it in the Form when the page is loaded (function "insertAddPhoneButton()").
- Append a button to each "Phone" field to make it removable (function "insertRemovePhoneButton()").
- Handle the "click" event of the "Add Phone" button to insert a new Form field. Update the Form with the new item and the Form data by using the
setOptions()method. - Handle the "click" event of the remove button to remove the specified "Phone" input.
@model ProjectName.Models.PersonViewModel
@(Html.Kendo().Form<PersonViewModel>()
.Name("exampleForm")
.HtmlAttributes(new { action = @Url.Action("Submit", "Home"), method = "POST" })
.Orientation("horizontal")
.FormData(Model)
.Layout("grid")
.Grid(g => g.Cols(2).Gutter(60))
.Items(items =>
{
items.AddGroup()
.Label("Personal details")
.Items(i =>
{
i.Add()
.Field(f => f.FirstName)
.Label(l => l.Text("First Name"));
i.Add()
.Field(f => f.LastName)
.Label(l => l.Text("Last Name"));
});
items.AddGroup()
.Label("Phones")
.Items(i =>
{
i.Add()
.Field(f => f.Phones[0])
.Label(l => l.Text("Phone 1"))
.Editor(e => e.MaskedTextBox().Mask("(999) 000-0000"));
i.Add()
.Field(f => f.Phones[1])
.Label(l => l.Text("Phone 2"))
.Editor(e => e.MaskedTextBox().Mask("(999) 000-0000"));
});
})
)
<script>
function insertRemovePhoneButton(phoneFields) {
$.each($(phoneFields), function(i,v){
var deletePhoneBtn = `<em id="removePhoneBtn_${i}"></em>`;
$(deletePhoneBtn).insertAfter($(this));
$(`#removePhoneBtn_${i}`).kendoButton({
icon: "trash",
click: onRemoveBtnClick
});
});
}
function insertAddPhoneButton() {
var addPhoneBtn = '<button id="addPhoneBtn">Add Phone</button>';
$(".k-form-fieldset").eq(1).append($(addPhoneBtn));
$("#addPhoneBtn").kendoButton({
icon: "plus",
click: onAddPhone
});
}
function onRemoveBtnClick(e) {
var phoneId = $(e.sender.element).attr("id").split("_")[1];
var formComponent = $("#exampleForm").data("kendoForm");
var formData = formComponent.options.formData;
var phoneItems = formComponent.options.items[1].items;
var currnetPhonesData = formComponent._model.Phones;
formData.Phones.splice(phoneId, 1);
phoneItems.splice(phoneId, 1);
currnetPhonesData.splice(phoneId, 1);
var newPhoneItems = [];
for(var i = 0; i < formData.Phones.length; i++) {
newPhoneItems.push({
"field": `Phones[${i}]`,
"editor": "MaskedTextBox",
"editorOptions": {
"mask": "(999) 000-0000"
},
"label": {
"text": `Phone ${i + 1}`
},
"shouldRenderHidden": false
});
formData.Phones[i] = currnetPhonesData[i];
}
formComponent.options.items[1].items = newPhoneItems;
formComponent.setOptions({
formData: formData,
items: formComponent.options.items
});
insertRemovePhoneButton($('[data-role="maskedtextbox"]'));
insertAddPhoneButton();
}
function onAddPhone(e) {
var formComponent = $("#exampleForm").data("kendoForm");
var formData = formComponent.options.formData;
var phoneItems = formComponent.options.items[1].items;
var currnetPhonesData = formComponent._model.Phones;
var totalPhones = phoneItems.length;
formData.Phones.push("");
phoneItems.push({
"field": `Phones[${totalPhones}]`,
"editor": "MaskedTextBox",
"editorOptions": {
"mask": "(999) 000-0000"
},
"label": {
"text": `Phone ${totalPhones + 1}`
},
"shouldRenderHidden": false
});
for(var i = 0; i < formData.Phones.length; i++) {
if(currnetPhonesData[i] != formData.Phones[i]) {
formData.Phones[i] = currnetPhonesData[i];
}
}
formComponent.setOptions({
formData: formData,
items: formComponent.options.items
});
insertRemovePhoneButton($('[data-role="maskedtextbox"]'));
insertAddPhoneButton();
}
$(document).ready(function(){
insertRemovePhoneButton($('[data-role="maskedtextbox"]'));
insertAddPhoneButton();
});
</script>
For a runnable example based on the code above, refer to the REPL example on dynamically adding and removing Form items.
More ASP.NET MVC Form Resources
[ASP.NET MVC Form Documentation]((/aspnet-mvc/html-helpers/layout/form/overview)
Telerik UI for ASP.NET MVC Video Onboarding Course (Free for trial users and license holders)