Generate code for knockout binding for ASP.Net MVC - asp.net-mvc

I have worked with knockout a little bit. It is a good client side data binding js library. A template is bound and populated on the client side as follows:
<h3>Are you sure you want to delete this?</h3>
<fieldset>
<legend>Delete</legend>
<div class="display-label">
Student Id
</div>
<div class="display-field">
<input data-bind="value: StudentId" />
</div>
<div class="display-label">
First Name
</div>
<div class="display-field">
<input data-bind="value: FirstName" />
</div>
<div class="display-label">
Last Name
</div>
<div class="display-field">
<input data-bind="value: LastName" />
</div>
<div class="display-label">
Age
</div>
<div class="display-field">
<input data-bind="value: Age" />
</div>
</fieldset>
the above way we write html to bind data
this way populate template by js code
$(function () {
ko.applyBindings(StudentListVM);
StudentListVM.getStudents();
});
//View Model
var StudentListVM = {
Students: ko.observableArray([]),
getStudents: function () {
var self = this;
$.ajax({
type: "GET",
url: '/Student/FetchStudents',
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (data) {
self.Students(data); //Put the response in ObservableArray
},
error: function (err) {
alert(err.status + " : " + err.statusText);
}
});
},
};
self.editStudent = function (student) {
window.location.href = '/Student/Edit/' + student.StudentId;
};
self.deleteStudent = function (student) {
window.location.href = '/Student/Delete/' + student.StudentId;
};
//Model
function Students(data) {
this.StudentId = ko.observable(data.StudentId);
this.FirstName = ko.observable(data.FirstName);
this.LastName = ko.observable(data.LastName);
}
The above code works and generates the UI on the client side.
I would like to know if there is any scaffolding option in MVC which generates the above html with binding expression and also generates the required js view model.
If this does not exist then I would appreciate suggestions on how to achieve it.

Take a look on Knockout mvc
You can write appropriate #helper method
Don't forget about T4
you can write your own extension for HtmlHelper

Related

Get object from controller to view using ajax in .net mvc core

Controller:
[HttpGet]
public IActionResult Edit(int id)
{
Teacher teacher = teacherService.GetTeacherById(id);
EditTeacherData(teacher);
return View();
}
public JsonResult EditTeacherData( Teacher teacher)
{
return Json(teacher);
}
Ajax:
$.ajax({
type: "GET",
url: "/Teacher/EditTeacherData",
contentType: "application/json;charset=utf-8",
dataType: "json",
success: function (data) {
debugger;
console.log(data)
},
error: function (response) {
debugger;
alert('eror');
}
});
View:
#model StudentTeacher.Models.TeacherViewModel
#{
ViewData["Title"] = "EditTeacher";
}
<h1>EditTeacher</h1>
<h4>Teacher</h4>
<hr />
<div class="row">
<div class="col-md-4">
<form id="AddTeacherForm">
<div asp-validation-summary="ModelOnly" class="text-danger"></div>
<input type="hidden" asp-for="TeacherId" id="TeacherId" />
<div class="form-group">
<label asp-for="Name" class="control-label"></label>
<input asp-for="Name" class="form-control" id="Name" />
<span asp-validation-for="Name" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="Designation" class="control-label"></label>
<input asp-for="Designation" class="form-control" id="Designation" />
<span asp-validation-for="Designation" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="Education" class="control-label"></label>
<input asp-for="Education" class="form-control" id="Education" />
<span asp-validation-for="Education" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="JoiningDate" class="control-label"></label>
<input asp-for="JoiningDate" class="form-control" id="JoiningDate"/>
<span asp-validation-for="JoiningDate" class="text-danger"></span>
</div>
<div class="form-group">
<input type="submit" value="Save" class="btn btn-primary" id="Submit" />
</div>
</form>
</div>
</div>
teacherService is a service that retrieves data that match with id. But it return null object. When I use this EditTeacherData(teacher); ajax not return a null object But in debugger model show value takes this function. I just wanna get an object through ajax and show data in the field via ajax.
Obviously, there is no parameter passed in to the controller in your ajax, so Edit method will never receive the parameter passed in.
You can implement it with EF core. If you want to use ajax, you can refer to this.
You can also achieve it without ajax, it much easier, please refer to this.
You are not sending data from your ajax request. Please read this for clear understanding
$('#Submit').click(function(){
var formData = $('#AddTeacherForm').serialize();
$.ajax({
type: "GET",
url: "/Teacher/EditTeacherData",
data: formData,
success: function (data) {
debugger;
console.log(data)
},
error: function (response) {
debugger;
alert('eror');
}
});
})

How to check if a url belongs to a website that exists?

I am making a website where in a form, users can input a web page address. I was going to go with checking if the url is formatted correctly like an actual url which I think is the sloppy way and instead I want to check if url belongs to an actual website. Like, let's say user inputs www.pyrtyrmyrsyr.org, that is a valid address, but it doesn't lead to a website. Let's say user inputs www.python.org, that is both a valid address and leads to a website that exists.
And how can I check this validity before the form is sent and after input is given? Make the form's "send" button not clickable if url is not valid?
EDIT : Realized I didn't add any code of my view, apologize for that, also forgot to mention I use Bootstrap for View.
This is the form I use, what I am trying to do is use "Check" button, to check validity, by taking URL inside form-control with "id=url"
<div>
<div class="row">
<div class="col-md-12">
<h2 style="margin-left:20px; margin-top:10px">Add a Link</h2>
<form action="~/Link/Create" method="post">
<div class="form-group well clearfix" style="margin-left:20px; margin-right:20px; margin-top:20px">
<br />
<div class="row">
<label for="name" class="col-lg-2">URL:</label>
<div class="col-lg-9">
<input class="form-control" id="url" placeholder="URL" name="Address" /><br />
</div>
<div class="col-lg-1">
<button type="button" class="btn btn-primary" id="checkurl">Check</button>
</div>
</div>
<div class="row">
<div class="col-lg-2">
<label for="name">Interval:</label>
</div>
<!--<div class="col-lg-10">
<input class="form-control" placeholder="Interval to check (minutes)" name="Interval" /><br />
</div>-->
<div class="col-lg-5">
<select class="form-control" id="sel1">
<option>Minutes</option>
<option>Hours</option>
<option>Days</option>
<option>Weeks</option>
<option>Months</option>
</select>
</div>
<div class="col-lg-5">
<select class="form-control" id="sel2">
<option>Minutes</option>
<option>Hours</option>
<option>Days</option>
<option>Weeks</option>
<option>Months</option>
</select>
</div>
</div>
<div class="row">
<button class="btn btn-success pull-right" type="submit" style="width:200px; margin-right:15px">Save</button>
</div>
</div>
</form>
</div>
</div>
</div>
As far as I searched so far, connection to another domain/website is not possible using Javascript or anything similar so I need a server-side language, so I need to take this url, send it to control and return a true/false value after checking connection.
You can use Remote Validation in Asp.NET MVC. Let you have following property in your model.
public string URL {get; set;}
Add Remote attribute to your property like
[Remote("YourAction", "YourController", HttpMethod = "GET", ErrorMessage = "URL is not valid.")]
public string URL {get; set;}
Now write the following code in your specified action of the controller.
public class YourController : Controller
{
[AllowAnonymous]
public ActionResult YourAction(string URL)
{
try
{
//Check here by hitting your URL using HTTPClient or WebClient that it is returning something or not.
WebClient wc = new WebClient();
string HTMLSource = wc.DownloadString(URL);
return Json(true, JsonRequestBehavior.AllowGet); //Return true if it is valid.
}
catch (Exception)
{
return Json(false, JsonRequestBehavior.AllowGet); //Return false if it is not vald.
}
}
}
You must have to add following configurations in your web.config
<appSettings>
<add key="ClientValidationEnabled" value="true" />
<add key="UnobtrusiveJavaScriptEnabled" value="true" />
</appSettings>
Your code on view will be like
#Html.EditorFor(model => model.URL, new { type = "url", #class = "form-control", placeholder = "URL" } })
#Html.ValidationMessageFor(model => model.URL, "", new { #class = "text-danger" })
Solved it:
Added a bool to my model:
public bool Valid { get; set; }
Changed my view a little:
<div class="row">
<label for="name" class="col-lg-2">URL:</label>
<div class="col-lg-9">
<input class="form-control" id="url" placeholder="URL" name="Address" /><br />
</div>
<div class="col-lg-1">
<button type="button" class="btn btn-primary pull-right" id="checkurl">Check</button>
</div>
<input type="hidden" name="Valid" id="Validity"/>
</div>
Used the following codes, one for checking validity, other to reset form being usable if input is changed
$('#checkurl').click(function () {
var address = $('#url').val();
$.ajax({
url: "/Control/CheckUrl",
type: "POST",
data: JSON.stringify({ url: address }),
cache: false,
dataType: 'json',
contentType: 'application/json; charset=utf-8',
error: function (xhr) {
alert('Error: ' + xhr.statusText);
},
success: function (result) {
if (result) {
document.getElementById("Validity").value = true;
document.getElementById("saveBut").disabled = false;
}
else {
document.getElementById("Validity").value = false;
document.getElementById("saveBut").disabled = true;
}
},
async: true,
processData: false
});
});
$('#url').change(function ()
{
if (document.getElementById("saveBut").disabled == false)
{
document.getElementById("Validity").value = false;
document.getElementById("saveBut").disabled = true;
}
});
Ajax code there leads to a controller function that reformats URL a bit and checks validity:
public ActionResult CheckUrl(string url)
{
try
{
if (String.IsNullOrEmpty(url)) return Json(false, JsonRequestBehavior.AllowGet); ;
if (url.Equals("about:blank")) return Json(false, JsonRequestBehavior.AllowGet); ;
if (!url.StartsWith("http://") && !url.StartsWith("https://"))
{
url = "http://" + url;
}
WebClient wc = new WebClient();
string HTMLSource = wc.DownloadString(url);
return Json(true, JsonRequestBehavior.AllowGet);
}
catch (Exception)
{
return Json(false, JsonRequestBehavior.AllowGet);
}
}
It works flawlessly and as desired.

Cannot upload picture using formdata Asp.net-mvc

I fail to upload pictures using formdata. This is my previous code which was working fine(This is just part of a form):
<div class="fileinput fileinput-new" data-provides="fileinput" style="width: 100%;">
<div class="fileinput-preview" data-trigger="fileinput" style="margin: 10px 0px;"></div>
<div>
<span class="btn btn-default btn-file">
<input type="file" id="filePicture" name="filePicture">
</span>
</div>
</div>
And this is my Ajax call:
$(document).on("click", "#sledBuckSaveBtn", function() {
event.preventDefault();
event.stopPropagation();
var fd = new FormData(document.getElementById("saveSledBuckForm1"));
$.ajax({
type: "POST",
url: "/SledBuck/EditFromSledTestDetails", //url,
data: fd,
processData: false, // tell jQuery not to process the data
contentType: false,
success: function (result) {
var title = "Error", msgtype = "error";
if (result) {
title = "Success";
msgtype = "success";
}
document.location.reload();
}
});
});
But my requirement has changed, I need to use Krajee plugin to create an input type:
Here my new code:
<div class="col-md-9">
<input id="input-#Model.PictureIdList[i]" type="file" class="file" data-show-upload="false" data-show-caption="true" data-input-id="#Model.PictureIdList[i]">
</div>
what problem am I facing. I think the reason is I might need to do configuration for Krajee plugin but I'm not sure. Any suggestions?
I just found the answer. I lacked the name of the file input. Just do like this and the file will be regconized:
<input id="input-#Model.PictureIdList[i]" name= "fileInput" type="file" class="file" data-show-upload="false" data-show-caption="true" data-input-id="#Model.PictureIdList[i]">

MVC/Razor File Upload View

I self admitted newbie, but I have a view with some code I pasted to provide a file upload. The function works but if the code is in, the "Save" button for the View that was already there stops working. If I had to guess it has something to do with the "HTML.BeginForm" line being there twice.
Here is the top of the view,
#model BrooksSOR.Models.dataOffender
#{
ViewBag.Title = "Edit";
}
<h2>Edit</h2>
<div >
<h2>Upload Files in MVC</h2>
<img src="#Model.Photograph" width="250" height="250" />*
#using (Html.BeginForm("FileUpload", "SOR",
FormMethod.Post, new { enctype = "multipart/form-data" }))
{
<input name="uploadFile" type="file" />
<input type="submit" value="Upload File"/>
<input type="hidden" name="parmPersonID" value="#Model.PersonID" />
}
</div>
#using (Html.BeginForm())
{
#Html.AntiForgeryToken()
#Html.ValidationSummary(true)
<fieldset>
<legend>dataOffender</legend>
<p>
<input type="submit" value="Save" />
<input id="Details" type="button" value="Details" />
</p>
</fieldset>
Remove the #html.BeginForm
The script you would need to send for a file and some other fields with it.
//Purpose: Form Submit: SAVE Client
document.getElementById('frmPage').onsubmit = function (e) {
debugger;
var file = document.getElementById('fileToUpload').files[0];
var filename;
if (file) {
filename = file.name;
}
else {
filename = "";
}
$('#Image').val(filename);
var formObj = $(this);
var formURL = '#Url.Action("SaveMethod", "ControllerName")';
var formData = new FormData(this);
$.ajax({
url: formURL,
type: 'POST',
data: formData,
mimeType: "multipart/form-data",
contentType: false,
cache: false,
processData: false,
success: function (data, textStatus, jqXHR) {
debugger;
alert("Client saved successfully");
},
error: function (jqXHR, textStatus, errorThrown) {
}
});
e.preventDefault(); //Prevent Default action.
}
This is the design:
<div>
<form id="frmPage" class="form-horizontal">
<div class="form-body">
<div class="form-group">
<label id="lblImage" class="col-md-3 control-label">Upload File</label>
<div class="col-md-4">
<input type="file" id="fileToUpload" name="file" />
</div>
</div>
<div class="modal-footer" style="margin-top: 0px">
<div class="pull-right">
<button type="submit" id="btnSave" class="btn blue Save">Save</button>
</div>
</div>
</form>
</div>
Here: The btnSave is submit type, so it will submit that particular form. and form named frmPage will do the jquery script we added.

Saving data through AngularJS

Update:
I have replaced <input type=submit to <button ... and also remove the form tag from my html, after modifying my code i do not see it executing my JS and I have a debugger line in the code and it does not break....
I'm trying to POST data and I have all the code in placed and wired-up correctly (I believe) but when I try to Submit my page # My page gets refreshed, I don't see any event is firing and I have set debugger in the JS, and I do not see any JS error in developer tool
What I'm missing here apart from my code?
here is my code:
//HML code
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>My AngularJS App</title>
<script src="../AppScripts/RequesterAdd.js"></script>
</head>
<body>
<form>
<div ng-app="requesterAddModule" ng-controller="requesterAddController" class="container">
<h2> add requester</h2>
<div ng-show="ShowMessage">Record saved Successfully</div>
#Html.AntiForgeryToken()
<div class="form-horizontal">
<h4>HostModel</h4>
<hr />
<div class="form-group">
<div>First Name:</div>
<div class="col-md-10">
<input type="text" ng-model="FirstName" required class="form-control input-lg" placeholder="First Name" />
</div>
</div>
<div class="form-group">
<div>Middle Name:</div>
<div class="col-md-10">
<input type="text" ng-model="MiddleName" required class="form-control input-lg" placeholder="Middle Name" />
</div>
</div>
<div class="form-group">
<div>Last Name:</div>
<div class="col-md-10">
<input type="text" ng-model="LastName" required class="form-control input-lg" placeholder="Last Name" />
</div>
</div>
<div class="form-group">
<div>eMail Address:</div>
<div class="input-group">
<span class="input-group-addon"><i class="fa fa-envelope"></i></span>
<input type="text" ng-model="Email" required class="form-control input-lg" placeholder="Email Address" />
</div>
</div>
<div class="form-group">
<div>Is Host Active:</div>
<div class="col-md-10">
<input type="checkbox" ng-model="Active" required class="control-label col-md-2" />
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<input type="submit" id="btnCreate" data-ng-click="addRequester_ClickEvent" value="Create" class="btn btn-primary" />
</div>
</div>
</div>
<div>
#Html.ActionLink("Back to List", "Index")
</div>
</div>
</form>
</body>
</html>
//JS:
var requesterAddModule = angular.module("requesterAddModule", []);
requesterAddModule.factory('requesterAddService',
['$http', function ($http) {
return {
addRequester: function (reqesterData) {
console.log(reqesterData);
debugger;
$http({
url: 'PersistRequester',
method: 'POST',
data: reqesterData
}).then (function (response) {
if (response !== 'undefined' && typeof(response) == 'object') {
window.location.href = '/'
}
},
function(response) {
//failed
}
);
}
};
}]);
requesterAddModule.controller('requesterAddController', ['$scope', '$http', '$window', 'requesterAddService', function ($scope, $http, $window, requesterAddService) {
$scope.addRequester_ClickEvent = function () {
var req = {};
debugger;
req["FirstName"] = $scope.FirstName;
req["MiddleName"] = $scope.MiddleName;
req["LastName"] = $scope.LastName;
req["Email"] = $scope.Email;
req["Active"] = $scope.Active;
requesterAddService.addRequester(req);
}
}]);
//MVC Server side code:
[HttpPost]
public JsonResult PersistRequester(Requester requester)
{
var req = requester;
//if (ModelState.IsValid)
// {
req.CreatedDateTime = DateTime.Now;
db.Requesters.Add(requester);
db.SaveChanges();
return Json(new { Status = "Success" });
//}
}
You're using a form without a method and action which will by default post to the current url. I would highly recommend not to use a form or at least not using an <input type="submit" /> which will default in all the browsers to submit the form.
You're clearly using Bootstrap 3 here so why not just remove the form tag and the submit button and replace it with another element which will not trigger the form post and style it with class="btn btn-primary". Some could argue against this practise along the graceful degradation guidelines but since this particular form is not built from ground up to support the non-js scenario, it is best not to allow browser submit at all.
Also, in your service where you're doing the actual post, you specifically tell the page to reload.
if (response !== 'undefined' && typeof(response) == 'object') {
window.location.href = '/'
}
You should pass this data back to the viewmodel so that the view can re-render and display the response.
If you change the url, the view state is lost and the page will simply render again to the initial state.
instead line
<input type="submit" id="btnCreate" data-ng-click="addRequester_ClickEvent" value="Create" class="btn btn-primary" />
please do
<button id="btnCreate" data-ng-click="addRequester_ClickEvent()" class="btn btn-primary" >Create</button>
I've just tested and is working for me replace:
<input type="submit" id="btnCreate" data-ng-click="addRequester_ClickEvent" value="Create" class="btn btn-primary" />
with
<button id="btnCreate" data-ng-click="addRequester_ClickEvent()" value="Create" class="btn btn-primary" >submit</button>
and I've change a bit your service to :
requesterAddModule.factory('requesterAddService',
['$http', function ($http)
{
return {
addRequester: function (reqesterData)
{
console.log(reqesterData);
debugger;
$http.post('PersistRequester', reqesterData).then(function (response)
{
if (response !== 'undefined' && typeof (response) == 'object') {
window.location.href = '/'
}
},
function (response)
{
//failed
}
);
}
};
}]);
it's posting to /home/PersistRequester if method 'PersistRequester' exist in other controller ie : foo controller change
$http.post('PersistRequester', reqesterData).then(function (response)
to $http.post('foo/PersistRequester', reqesterData).then(function (response)

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