Disable form Submit based on validation - asp.net-mvc

I am learning ASP.NET Core (v 2.0). There is a form with a few input text boxes and a submit button. I want to only allow a user to submit a valid form, so while the form is incomplete, I want the Submit button to be disabled.
Is there a way to easily do that using ASP.NET Core model validation?
Thanks.

There is nothing built into ASP.NET MVC that does this for you automatically. The UI pattern you are asking about would require JavaScript coding.
You could download and reference a validation library, like the jQuery Validation Plugin. Then write some JavaScript in your page to check if the form is valid on blur of each of the form inputs by checking $("#myForm").valid(), and only enable the submit button if the form is valid.
See attached snippet for an example.
var $form = $("#myform");
var $submitbutton = $("#submitbutton");
$form.on("blur", "input", () => {
if ($form.valid()) {
$submitbutton.removeAttr("disabled");
} else {
$submitbutton.attr("disabled", "disabled");
}
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.17.0/jquery.validate.min.js"></script>
<form id="myform">
<input type="text" name="text1" required />
<br/>
<input type="text" name="text2" required />
<br/>
<button type="submit" id="submitbutton" disabled>Submit Enabled When Valid</button>
</form>

Related

How do I do a POST back on a element event such as <select ... onchange....> [duplicate]

I have a form with id theForm which has the following div with a submit button inside:
<div id="placeOrder"
style="text-align: right; width: 100%; background-color: white;">
<button type="submit"
class='input_submit'
style="margin-right: 15px;"
onClick="placeOrder()">Place Order
</button>
</div>
When clicked, the function placeOrder() is called. The function changes the innerHTML of the above div to be "processing ..." (so the submit button is now gone).
The above code works, but now the problem is that I can't get the form to submit! I've tried putting this in the placeOrder() function:
document.theForm.submit();
But that doesn't work.
How can I get the form to submit?
Set the name attribute of your form to "theForm" and your code will work.
You can use...
document.getElementById('theForm').submit();
...but don't replace the innerHTML. You could hide the form and then insert a processing... span which will appear in its place.
var form = document.getElementById('theForm');
form.style.display = 'none';
var processing = document.createElement('span');
processing.appendChild(document.createTextNode('processing ...'));
form.parentNode.insertBefore(processing, form);
It works perfectly in my case.
document.getElementById("form1").submit();
Also, you can use it in a function as below:
function formSubmit()
{
document.getElementById("form1").submit();
}
document.forms["name of your form"].submit();
or
document.getElementById("form id").submit();
You can try any of this...this will definitely work...
I will leave the way I do to submit the form without using the name tag inside the form:
HTML
<button type="submit" onClick="placeOrder(this.form)">Place Order</button>
JavaScript
function placeOrder(form){
form.submit();
}
You can use the below code to submit the form using JavaScript:
document.getElementById('FormID').submit();
<html>
<body>
<p>Enter some text in the fields below, and then press the "Submit form" button to submit the form.</p>
<form id="myForm" action="/action_page.php">
First name: <input type="text" name="fname"><br>
Last name: <input type="text" name="lname"><br><br>
<input type="button" onclick="myFunction()" value="Submit form">
</form>
<script>
function myFunction() {
document.getElementById("myForm").submit();
}
</script>
</body>
</html>
HTML
<!-- change id attribute to name -->
<form method="post" action="yourUrl" name="theForm">
<button onclick="placeOrder()">Place Order</button>
</form>
JavaScript
function placeOrder () {
document.theForm.submit()
}
If your form does not have any id, but it has a class name like theForm, you can use the below statement to submit it:
document.getElementsByClassName("theForm")[0].submit();
I have came up with an easy resolve using a simple form hidden on my website with the same information the users logged in with. Example: If you want a user to be logged in on this form, you can add something like this to the follow form below.
<input type="checkbox" name="autologin" id="autologin" />
As far I know I am the first to hide a form and submit it via clicking a link. There is the link submitting a hidden form with the information. It is not 100% safe if you don't like auto login methods on your website with passwords sitting on a hidden form password text area...
Okay, so here is the work. Let’s say $siteid is the account and $sitepw is password.
First make the form in your PHP script. If you don’t like HTML in it, use minimal data and then echo in the value in a hidden form. I just use a PHP value and echo in anywhere I want pref next to the form button as you can't see it.
PHP form to print
$hidden_forum = '
<form id="alt_forum_login" action="./forum/ucp.php?mode=login" method="post" style="display:none;">
<input type="text" name="username" id="username" value="'.strtolower($siteid).'" title="Username" />
<input type="password" name="password" id="password" value="'.$sitepw.'" title="Password" />
</form>';
PHP and link to submit form
<?php print $hidden_forum; ?>
<pre>Forum</pre>

MVC Form Submit Button will Conditionally have OnClick Event

Posting a form from .cshtml. If the Email Textbox has the value of "Admin" and the Password TextBox has the value of "12345" I want to include an onclick event on the submit button.
I thought about if/else block but what to place in the if condition below where you see question mark (?):
<form class="fvalidate" action="/entry" method="post">
<input type="text" name="Email" class="email required"/>
<input type="password" name="Sifre" class="required" />
#if (?)
{
<input type="submit" value="LOG IN" class="mTop15"
onclick="ibFunc.openBoxOpen('/entry/adv'); return false;" />
}
else
{
<input type="submit" value="LOG IN" class="mTop15" />
}
</form>
How could I accomplish this?
You need to understand the flow of the application and what fires when. You seem to be mixing Client and Server side technology.
The flow should be
Step 1 Submit the form
Step 2 The controller validates the login and works out whether they are admin or not.
Step 3 The controller redirects the user to the /entry or /entry/adv page depending on whether they are an admin or not
Step 4 On the /entry page don't fire the javascript
Step 4a On the /entry/adv page fire the javascript
To answer your question directly. There is nothing you can put in the place of the ? that will do what you want because that is Razor code which is executed on the server before the user has interacted with the page.
Do the control in POST in the controller, when the "Admin" submit the form make an if then use
return RedirectToAction("adv", "entry");

asp.net mvc redirect to action and passing a parameter from user input

I have a page with a input box and a button, when the user clicks the button i want to redirect to a controller action that has as parameter the value of the input box.
<input id="CodProiect" type="text" />
<input id="Cauta" type="button" value="Cauta" onclick="window.location.href='#Url.Action("Cauta", "Componente", new { CodProiect = "param" })';"/>
How can i get the "param" from the input box ?
You could just use a form with a GET method
<form action="#Url.Action("Cauta", "Componente")" method="GET">
<input id="CodProiect" name="CodProiect" type="text" />
<input id="Cauta" type="submit" value="Cauta" />
</form>
The form will add the parameter as part of the query string of the URL e.g. www.yoursite.com/Cauta/Componente?CodProiect=user+entered+value
Value of the Action is prepared at server side and sent to the browser so you cannot have the value at the server when it is a user input.
You can use jquery to change the URL at client side.
Also passing state in an PRG scenario is a common problem in ASP NET MVC. You can either:
Store it temporarily in session
Pass it as a parameter in URL
Use a form.
Form:
<form action="Componente/Cauta">
<input id="CodProiect" type="text" />
<input id="Cauta" type="submit" value="Cauta" />
</form>
Controller:
public ActionResult Cauta(string CodProiect)
{
//Do some stuff
}
More info: http://weblogs.asp.net/scottgu/archive/2008/09/02/asp-net-mvc-preview-5-and-form-posting-scenarios.aspx
Syntax may be outdated, but you get the point...

Client validate non-model bound checkbox while using MVC 2 jQuery Validation

Have: Using ASP.NET MVC 2, DataAnnotationsModel based server validation, and client validation with jQuery. Anything in my model is validated perfectly on the client with jQuery based validation (jQuery.validate and MicrosoftMvcJQueryValidation.js).
Need: Adding an additional HTML <input type="checkbox" id="terms" /> to my form. I need jQuery validation to require that this checkbox is checked AND somehow hook it in with whatever jQuery client script MVC is automagically controlling. Yes, I know it won't validate on the server side, but I don't need or want it to.
Seems like it should be simple but I'm new to MVC, a total beginner at jQuery, and my searches have been coming up blank.
Any help would be appreciated!
Here's a solution. It mimics what mvc does to hook into jQuery validation. So there's a checkbox called Accept that doesn't belong to the model. The script must go after the form and it adds all the validation meta data for that field.
<%
Html.EnableClientValidation(); %>
<% using(Html.BeginForm("Show"))
{ %>
<%= Html.EditorForModel() %>
<div class="editor-field">
<%= Html.CheckBox("Accept", new { #class = "required" })%>
<span class="field-validation-valid" id="Accept_validationMessage"></span>
</div>
<input type="submit" value="Submit" />
<%} %>
<script type="text/javascript">
window.mvcClientValidationMetadata[0].Fields.push({
FieldName: "Accept",
ReplaceValidationMessageContents: true,
ValidationMessageId: "Accept_validationMessage",
ValidationRules: [{ ErrorMessage: "The Accept field is required.", ValidationType: "required", ValidationParameters: {}}]
});
</script>
Might I suggest using a ViewModel for every View (put all of your dataannotations in there). Then you can create a boolean model property for your checkbox and set it to required.
From there, if you're posting the model back to the controller, you can simply use AutoMapper to map the ViewModel to the needed model, or simply map the properties yourself.
Either way, it is good practice to use a ViewModel for every view. Remember a ViewModel's job is to try and contain everything required in the view. This definitely means that it can and will have other data that is not required in the Model.
Try this
$(document).ready(function() {
//// Assuming your form's ID is 'form0'
$("#form0").submit(function() {
if ($("#terms").attr('checked')) {
return true;
}
else
{
//// Error message if any
return false;
}
});
});

ASP.NET MVC Ajax.BeginForm eats params of submit button clicked. Looks like bug

If you are using Ajax.BeginForm() with multiple submit buttons similar to this:
// View.aspx
<% using (Ajax.BeginForm("Action", "Controller",
new AjaxOptions { UpdateTargetId = "MyControl", }))
{ %>
<span id="MyControl">
<% Html.RenderPartial("MyControl"); %>
</span>
<% } %>
//MyControl.ascx
<%# Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl" %>
<input name="prev" type="submit" value="prev" />
<input name="next" type="submit" value="next" />
//...
Everything is submitted to the controller fine but the params for the submit button that was clicked are absent from the Request. In otherwords Request["next"] and Request["prev"] are always null.
I looked in to the JavaScript in Microsoft.MvcAjax.js and it looks like the function Sys_Mvc_MvcHelpers$_serializeForm completely skips over the inputs that are of type 'submit'.
This doesn't seem logical at all. How else can you find out what button has been clicked?
It looks like a bug to me. Is there any logical reason to skip these form parameters?
UPDATE: 2009-11-21
I downloaded MVC Release 2 Preview 2 and looked to see if this problem was fixed.
I did a quick test and found similar results to MVC Release 2 Preview 1.
I don't believe it is fixed yet.
UPDATE: 2009-08-07
I downloaded MVC Release 2 Preview 1 and looked to see if this problem was fixed.
I see a new function in the script MicrosoftMvcAjax.debug.js called _serializeSubmitButton and I see that when Ajax.BeginForm() renders the output there is a onclick event but when this event fires it generates an error "Microsoft JScript runtime error: 'Sys.Mvc.AsyncForm' is null or not an object".
In short it looks like a fix was attempted but it isn't working yet or I need to do something more. The bad news is if it isn't the later then Ajax Forms will be broken for everyone until the fix is complete.
UPDATE: 2009-05-07
I received feedback today from Microsoft confirming that this is a bug. They have logged the defect and said they hope to have it fixed in a future release.
For reference I'm leaving the details of my investigation that I submitted to Microsoft. Appologies for the long post but perhaps it will be useful for anyone trying to create a work around..
There are a couple problems in the Ajax support in MVC. To illustrate, consider the pattern illustrated in several examples on the web:
//===========
// View.aspx
//===========
<% using (Ajax.BeginForm("Action", "Controller",
new AjaxOptions { UpdateTargetId = "MyControl", HttpMethod = "POST"}))
{ %>
<span id="MyControl">
<% Html.RenderPartial("MyControl"); %>
</span>
<% } %>
//================
// MyControl.ascx
//================
<%# Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl" %>
<input name="startIndex" type="hidden" value="0" />
<%= Ajax.ActionLink("Prev", "PrevAction",
new AjaxOptions() { UpdateTargetId="MyControl", HttpMethod="POST"}) %>
<%= Ajax.ActionLink("Next", "NextAction",
new AjaxOptions() { UpdateTargetId="MyControl", HttpMethod="POST"}) %>
//...
Expected:
It is just a list that can the user can page forward and back without updating the entire page.
Given this setup. I expect 2 links labeled "Prev" and "Next". Clicking on "Prev" should fire the PrevAction method in the controller as a post and the value in the hidden field named "startIndex" should be available in the request parameters. I expect similar results when clicking the Next link.
Actual:
The reality is that the request object contains NONE of the form parameters even though it shows that it came in as a POST.
In order to get any of the parameters using action link they must be explicitly supplied through the variation of ActionLink that includes parameters. When this is used the parameters become part of the URL of the link which defeats the purpose of having a POST.
So why is the javascript wrong?
I dug into the javascript code that is used to handle the submit for the example I posted with my question and I now better understand why it doesn't handle it. The reason appears to be related to the way they have wired up events and what I believe is a shortcoming in Internet Explorer.
The way it currently works is that the Ajax.BeginForm() helper class generates a form tag with an onsubmit() function to intercept the form submit event. When the user clicks on a submit button the onsubmit() function fires and recieves parameters, one of which is the event.
The MicrosoftMvcAjax scripts look at the event, bundle up the form properties that are supposed to be submitted and sends the request off to the server. The problem is that per WC3 standards only the successful controls are supposed to be posted. In the case of submit buttons this is the button that was actually clicked. Under internet explorer there is no way to determine which button actually caused the submit event to fire so the script just skips all submit buttons.
(In Firefox the event contains a property called "explictOriginalTarget" which points to the button that actually caused the event in the first place)
Whats the fix?
Microsoft should be fixing it. However if we need something sooner I believe the only option is to hack the MicrosoftMvcAjax scripts to wire up events differently. I have found that the form can be wired to a handle a mousedown event where the button clicked can be saved in a global variable where the onsubmit handler can insert it into the post parameters.
Here is some code that I was testing to illustrate this technique. I have confirmed it works in both IE8 and FireFox but I haven't tried to hack it into the MVC Ajax scripts yet... If I get more time. I may post the results here.
<script type="text/javascript">
var _clicked = "";
function onSubmit(e) {
var targ;
if (!e) var e = window.event;
if (e.target) targ = e.target;
else if (e.srcElement) targ = e.srcElement;
if (targ.nodeType == 3) //defeat Safari bug
targ = targ.parentNode;
alert("OnSubmit:" + _clicked + " was clicked.");
return false;
}
function Click(e) {
var targ;
if (!e) var e = window.event;
if (e.target) targ = e.target;
else if (e.srcElement) targ = e.srcElement;
if (targ.nodeType == 3) //defeat Safari bug
targ = targ.parentNode;
_clicked = targ.name;
return true;
}
<form action="/Home/StandardForm" method="post"
onsubmit="onSubmit(event)" onmousedown="Click(event)">
<input type="submit" name="StdPrev" value="StdPrev" />
<input type="submit" name="StdNext" value="StdNext" />
</form>
In order for your submit buttons to be "successfull" controls as per the specification, they must be defined within the form element:
http://www.w3.org/TR/html401/interact/forms.html#successful-controls
If you can't nest your submit buttons inside your form, you'll probably need to use javascript (or jquery) to submit your form and pass in an additional paramater to indicate which button was clicked.
I suppose this has been fixed in MVC 2 (or it was never broken). Just make sure your HTML markup validates. The following example should show it works.
Vote.aspx:
<%# Page Language="C#" Inherits="System.Web.Mvc.ViewPage" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Vote</title>
</head>
<body>
<%using (Ajax.BeginForm("Vote", "Voting", new AjaxOptions { UpdateTargetId = "message" }))
{ %>
<%= Html.Hidden("itemId", "1")%>
<p>I love ASP.NET MVC!</p>
<input type="submit" name="voteValue" value="+" />
<input type="submit" name="voteValue" value="-" />
<%} %>
<p id="message"><%= TempData["message"] %></p>
<script type="text/javascript" src="<%= Url.Content("~/Scripts/MicrosoftAjax.js")%>"></script>
<script type="text/javascript" src="<%= Url.Content("~/Scripts/MicrosoftMvcAjax.js")%>"></script>
</body>
</html>
VotingController.aspx:
using System.Web.Mvc;
namespace Examples.FormWithMultipleSubmitButtons.Controllers
{
public class VotingController : Controller
{
public ViewResult Vote()
{
return View();
}
[HttpPost]
public ActionResult Vote(int itemId, string voteValue)
{
switch(voteValue)
{
case "+":
TempData["message"] = "You voted up.";
break;
case "-":
TempData["message"] = "You voted down.";
break;
default:
TempData["message"] = "Your vote was not recognized.";
break;
}
if(Request.IsAjaxRequest())
{
return Content(TempData["message"].ToString());
}
else
{
return View();
}
}
}
}
I had the same issue today (Oct 8, 2010) with my form with multiple submit buttons. The HTML didn't validate. I cleaned it up. It's still doesn't validate (but less error than the original) and now the value of clicked button is submitted.
A possible workaround could be to have each button in a seperate form routed to different actions on your controller.
Not ideal but could work.
I did the following:
<input id="btnSubmit" name="btnSubmit" type="hidden" value="" />
<input type="submit" name="btnSubmit" value="Delete" id = "btnDelete" onclick="$('#btnSubmit').attr('value','Delete');"/>
<input type="submit" name="btnSubmit" value="Save New" id = "btnSaveNew" onclick="$('#btnSubmit').attr('value','Save New');"/>
<input type="submit" name="btnSubmit" value="Save" id = "btnSave" onclick="$('#btnSubmit').attr('value','Save');"/>
i.e. defined a hidden input type with id of "btnSubmit" and on each button added the onclick event as onclick="$('#btnSubmit').attr('value','Delete');". this seems to work
as I was able to get the value of the button clicked in the controller:
public ActionResult SaveCreateBlot(string btnSubmit)
{
}

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