Range validation - asp.net

Suppose I have a table like:
create table
{
id numeric(5,3),
code varchar(10)
}
I have two text boxes in my form for the two fields.
Suppose if I type 1234578 in the first text box the error has been thrown in ASP.NET because I crossed the limit.
How can I validate in JavaScript or some other way for that particular range validation?

Let's take one textbox only. Attach an 'onchange' event handler to your textbox like this:
<input type="text" onchange="handleChange(this);" />
Then declare a script for validation like this:
<script>
function handleChange(input) {
if (input.value > ..your_value_here..) alert ("Invalid input");
}
</script>
Please note that the alert pop-up used here should not be actually used. Use a more subtle reminder at a more appropriate moment. The alert here is only to make things simple.

Related

GWT - Get the value of a checkbox from a servlet [duplicate]

I have an html form and i would like ALWAYS to have checkboxes to submit a value. How can i do that? I have one idea but i havent tried it and i am unsure if its the best way to do it (jquery to check if the box is checked or not, then set the value to 0/1 and check it off so it will submit)
Thanks to #Lazarus' idea, also mentioned by #BalusC, you can add an additional control to the form:
<input type="hidden" name="checkbox1" value="off">
<input type="checkbox" name="checkbox1" value="on"> My checkbox
Checkbox and the hidden fields must have the same name. The hidden input is always submitted as a default value. If the checkbox is checked then also it's submitted. So you have a list of 2 values for parameter "checkbox1", that you have to treat at server side.
...maybe a <select> tag would be more handy.
There is a legitimate reason for asking for something like this, although the behaviour envisioned here is not the right way to go about it. There is a problem with the checkbox when used correctly when editing existing data and that's that there is no way to determine whether no value was submitted because the field was not present on the form or because the user cleared all of the values. You can run into this sort of problem any time you include fields conditionally.
One could go to the trouble of maintaining a "view state", of course, but it's much easier to include a hidden "companion field" whenever a checkbox or select with the multiple option (which is also excluded when all selections are cleared) is displayed. The field should have a related but different name (a name from which the actual field name can be extracted). The Lotus Domino server has used fields named %%Surrogate_FieldNameHere for this purpose since (I believe) version 7 for exactly the reason I described here.
To tell you the truth, this feels like a big no-no.
Anyway here goes:
<script type="text/javascript">
$(document).ready(function () {
$('form').submit(function() {
$(this).find('input[type=checkbox]').each(function () {
$(this).attr('value', $(this).is(':checked') ? '1' : '0');
$(this).attr('checked', true);
});
});
});
</script>
HTML doesn't work that way. HTML checkboxes are specified as follows: if checked, then its name=value will be sent as request parameter. If unchecked, then its name=value will not be sent as request parameter. Note that when the value is unspecified, then most browsers default to "on". It's easier if you give all checkboxes the same name but a different and fixed value. This way you can obtain the checked ones as an array/collection.
If all checkboxes are already known beforehand in server side, you can just apply basic math to obtain the unchecked checkboxes:
uncheckedCheckboxes = allCheckboxes - checkedCheckboxes
If those checkboxes are created dynamically at the client side and therefore unknown beforehand in server side, then add for each checkbox a <input type="hidden"> field containing information about the dynamically created checkbox, so that the server side knows which checkboxes are all present as the moment of submission.
Although this goes against the HTML spec, if you know what you are doing, using this you no longer have to cater checkboxes which are handled completely differently when submitted - and for example naming fields with_brackets[] can actually be useable.
Complete solution
$(document).on('submit', 'form', function() {
$(this).find('input[type=checkbox]').each(function() {
var checkbox = $(this);
// add a hidden field with the same name before the checkbox with value = 0
if ( !checkbox.prop('checked') ) {
checkbox.clone()
.prop('type', 'hidden')
.val(0)
.insertBefore(checkbox);
}
});
});
Take note: the non-checked checkboxes now submit a value of "0"
Additionally, if you want to change the behaviour of a single form only, just alter the first line in the above snippet:
$(document).on('submit', 'form.your-class-name', function() {
// ...
});
if you have many checkbox, you can try this code:
<input type="checkbox" onclick="$(this).next().val(this.checked?1:0)"/> <input type="hidden" name="checkbox1[]"/>
If you have the following HTML:
<form id="myform" method="post" action="my/url">
<input type="checkbox" id="checkbox1" name="checkbox1"/>
<input type="checkbox" id="checkbox2" name="checkbox2"/>
<input type="checkbox" id="checkbox3" name="checkbox3"/>
</form>
Normal form submit:
On form submit, before submitting, change all values of checkboxes to 0 and 1 based on if checkbox is unchecked or checked. Like so:
$('#myform').submit(function() {
var $checkboxes = $('#myform').find('input[type="checkbox"]');// Select all checkboxes
$checkboxes.filter(':checked').val(1);// Set value to 1 for checked checkboxes
$checkboxes.not(':checked').val(0);// Set value to 0 for unchecked checkboxes
$checkboxes.prop('checked', true);// Change all checkboxes to "checked" so all of them are submitted to server
});
Note: Ugly thing about this code, while form is submitting, all checkboxes will appear as "checked" for a moment. But if you apply same concept for ajax form submit, it would be better.
AJAX form submit:
$.post('my/url', {
'checkbox1': $('#checkbox1').is(':checked') ? 1 : 0,
'checkbox2': $('#checkbox2').is(':checked') ? 1 : 0,
'checkbox3': $('#checkbox3').is(':checked') ? 1 : 0
}, function(response) {
// Server JSON response..
}, 'json');

Required Field conditional on button pressed

I may be having a blonde moment here.
I have a data entry form with the usual "Save" and "Cancel" buttons. In addition to these two I have another button "Approve". If the user clicks the "Approve" button I have an additional field (Approver) that must hold data. Is it possible to have a required field validator that is active on one button press but not another?
Yes This is possible :
You can Define multiple Validation group and decide witch group to validate depending on the clicked button, for that you should call javascript function onClientClient in order to validate the inputs :
See example bellow:
Triggering multiple validation groups with a single button
I think you will have to create a custom validator or just use javascript or jquery.
You can use the OnClientClick property of the buttons and add some javascript on there.
function CheckSave() {
if (/*text1 is filled*/) return true;
}
function CheckApprove() {
if (/*text1 is filled and text2 is filled*/) return true;
}
<asp:button id='btnSave' OnClientClick='return CheckSave()' OnClick='btnSave_Click' />
<asp:button id='btnApprove' OnClientClick='return CheckApprove()' OnClick='btnAprove_Click' />
you need the return in order for it to work

Jquery validation not working after clearing a form

I have applied validation through JQuery Validation Plugin on my page. The validation works fine but once the Clear button is hit to clear out all the fields on the form, and then the save button is clicked again, the validation doesn't fire and the form gets submitted. I have called the following javascript function on click of Clear button to clear out all the form fields :-
function ResetForm() {
jQuery(':input', '#form1')
.not(':button, :submit, :reset, :hidden')
.val('')
.removeAttr('checked')
.removeAttr('selected');
return false;
}
The Clear button is on a ChildPage and ResetForm function is on the MasterPage. Anybody have any guess why its getting submitted after clearing the fields ?
input is an element and not a attribute or a pseudo selectable, the main issue I see in your code is the : within the :input
Try changing to jQuery('#form1 input') to fetch the list of inputs
Also change the not() command to select filter the inputs by type
.not('[type="button"], [type="submit"], [type="reset"], [type="hidden"]')
also as for :hidden there's several factors you should know about this.
They have a CSS display value of none.
They are form elements with type="hidden".
Their width and height are explicitly set to 0.
An ancestor element is hidden, so the element is not shown on the page.
In light of your comment please try this tested version:
function resetForm()
{
$("#form1").find(':input').each(function()
{
var jelem = $(this);
switch(this.type)
{
case 'password':
case 'select-multiple':
case 'select-one':
case 'text':
case 'textarea':
jelem.val('');
break;
case 'checkbox':
case 'radio':
jelem.attr('checked',false);
}
});
}
#source: http://www.electrictoolbox.com/jquery-clear-form/
Another way to do this is to create a hidden input in your form but set the type as reset like so:
<input type="reset" style="display:none" />
and then do:
function resetForm()
{
$("#form1[type='reset']").click();
}
Actually the error was something else, the code provided by RobertPitt is correct for clearing of form fields and my code was also correct for clearing of form fields. But the problem is that, on the clear button I had applied a class="cancel" so that the form should not get submitted because it was an aspx:button.
But according to what is written in JQuery docs, clicking of a button whose class is cancel should skip the validation, but after that if I click on a normal submit button validation should fire which was not firing in my case.
I just removed the cancel class and it worked.
Does this help?
Reseting the form when usering the jquery validations plugin

How do I clear MVC client side validation errors when a cancel button is clicked when a user has invalidated a form?

I have a partial view that is rendered within a main view. The partial view takes advantage of System.ComponentModel.DataAnnotations and Html.EnableClientValidation().
A link is clicked, and div containing the partial view is displayed within a JQuery.Dialog().
I then click the save button without entering any text in my validated input field. This causes the client side validation to fire as expected, and display the '*required' message beside the invalid field.
When the cancel button is clicked, I want to reset the client side MVC validation back to it's default state and remove any messages, ready for when the user opens the dialog again. Is there a recommended way of doing this?
This answer is for MVC3. See comments below for help updating it to MVC 4 and 5
If you just want to clear the validation-messages so that they are not shown to the user you can do it with javascript like so:
function resetValidation() {
//Removes validation from input-fields
$('.input-validation-error').addClass('input-validation-valid');
$('.input-validation-error').removeClass('input-validation-error');
//Removes validation message after input-fields
$('.field-validation-error').addClass('field-validation-valid');
$('.field-validation-error').removeClass('field-validation-error');
//Removes validation summary
$('.validation-summary-errors').addClass('validation-summary-valid');
$('.validation-summary-errors').removeClass('validation-summary-errors');
}
If you need the reset to only work in your popup you can do it like this:
function resetValidation() {
//Removes validation from input-fields
$('#POPUPID .input-validation-error').addClass('input-validation-valid');
$('#POPUPID .input-validation-error').removeClass('input-validation-error');
//Removes validation message after input-fields
$('#POPUPID .field-validation-error').addClass('field-validation-valid');
$('#POPUPID .field-validation-error').removeClass('field-validation-error');
//Removes validation summary
$('#POPUPID .validation-summary-errors').addClass('validation-summary-valid');
$('#POPUPID .validation-summary-errors').removeClass('validation-summary-errors');
}
I hope this is the effect you seek.
If you are using unobtrusive validation that comes with MVC you can simply do:
$.fn.clearErrors = function () {
$(this).each(function() {
$(this).find(".field-validation-error").empty();
$(this).trigger('reset.unobtrusiveValidation');
});
};
------------------------------------------------------------------------
Third Party Edit:
This mostly worked in my case, but I had to remove the $(this).find(".field-validation-error").empty(); line. This appeared to affect the re-showing of the validation messages when resubmitting.
I used the following:
$.fn.clearErrors = function () {
$(this).each(function() {
$(this).trigger('reset.unobtrusiveValidation');
});
};
and then called it like this:
$('#MyFormId input').clearErrors();
function resetValidation() {
$('.field-validation-error').html("");
}
You can simply define a new function in jQuery:
$.fn.resetValidation = function () {
$(this).each(function (i, e) {
$(e).trigger('reset.unobtrusiveValidation');
if ($(e).next().is('span')) {
$(e).next().empty();
}
});
};
and then use it for your input fields:
$('#formId input').resetValidation();
Thank you. I had a similar question for a slightly different scenario. I have a screen where when you click one of the submit buttons it downloads a file. In MVC when you return a file for download, it doesn't switch screens, so any error messages which were already there in the validation summary remain there forever. I certainly don't want the error messages to stay there after the form has been submitted again. But I also don't want to clear the field-level validations which are caught on the client-side when the submit button is clicked. Also, some of my views have more than one form on them.
I added the following code (thanks to you) at the bottom of the Site.Master page so it applies to all of my views.
<!-- This script removes just the summary errors when a submit button is pressed
for any form whose id begins with 'form' -->
<script type="text/javascript">
$('[id^=form]').submit(function resetValidation() {
//Removes validation summary
$('.validation-summary-errors').addClass('validation-summary-valid');
$('.validation-summary-errors').removeClass('validation-summary-errors');
});
</script>
Thanks again.
You can tap into the validation library methods to do this.
There are two objects of interest: FormContext and FieldContext. You can access the FormContext via the form's __MVC_FormValidation property, and one FieldContext per validated property via the FormContext's fields property.
So, to clear the validation errors, you can do something like this to a form:
var fieldContexts = form.__MVC_FormValidation.fields;
for(i = 0; i < fieldContexts.length; i++) {
var fieldContext = fieldContexts[i];
// Clears validation message
fieldContext.clearErrors();
}
// Clears validation summary
form.__MVC_FormValidation.clearErrors();
Then, you can hook that piece of code to whichever event you need.
Sources for this (quite undocumented) insight:
http://bradwilson.typepad.com/presentations/advanced-asp-net-mvc-2.pdf (Mentions FieldContext)
https://stackoverflow.com/a/3868490/525499 (For pointing out this link, which metions how to trigger client-side validation via javascript)
In order to complete clear the validation artifacts including the message, the coloured background of the input field, and the coloured outline around the input field, I needed to use the following code, where this was (in my case) a Bootstrap modal dialog containing an imbedded form.
$(this).each(function () {
$(this).find(".field-validation-error").empty();
$(this).find(".input-validation-error").removeClass("input-validation-error");
$(this).find(".state-error").removeClass("state-error");
$(this).find(".state-success").removeClass("state-success");
$(this).trigger('reset.unobtrusiveValidation');
});
Here you can use simply remove error message
$('.field-validation-valid span').html('')
OR
$('.field-validation-valid span').text('')
I've this issue for "Validation summery" after form ajax submit and done it like this:
$form.find('.validation-summary-errors ul').html('');
and complete code is:
$("#SubmitAjax").on('click', function (evt) {
evt.preventDefault();
var $form = $(this).closest('form');
if ($form.valid()) {
//Do ajax call . . .
//Clear validation summery
$form.find('.validation-summary-errors ul').html('');
}
});

Passing hidden field from one page to another in querystring

I want to pass a query in a hidden filed from 1 page to another by querystring.
Can anyone help me out with the logic?
It's worth taking the time to learn jQuery. It's not very complicated, and it makes writing javascript much easier. There are also many jQuery plugins, such as jquery.url.
Also, as other posters have suggested, you may not wish to put the hidden field's value in the query string if you care about it being displayed to the user. However, if the data is present in a hidden field it will always be possible for a user to find it if they care to look.
If you really do want to put the hidden field in the query string and then extract it via non-jQuery javascript:
hiddenFieldPage.aspx
This form will take the user to processingPage.aspx?datum=someValue when it is submitted. You could probably also just use an ordinary link if nothing else needs to be submitted at the same time.
<form method="GET" action="processingPage.aspx">
<input type="hidden" name="datum" value="someValue">
<input type="submit">
</form>
or, inserting the value from code-behind:
RegisterHiddenField("datum", "someValue");
processingPage.aspx
This script will pop-up an alert box with the value of "datum" from the URL - assuming the form's method is set to "GET":
<script type="text/javascript">
function getUrlParam( key ) {
// Get the query and split it into its constituent params
var query = window.location.search.substring(1);
var params = query.split('&');
// Loop through the params till we find the one we want
for( var i in params ) {
var keyValue = params[i].split('=');
if( key == keyValue[0] ) {
return keyValue[1];
}
}
// Didn't find it, so return null
return null;
}
alert( getUrlParam("datum") );
</script>
If the form's method was set to "POST" (as it usually would be in ASP.NET), then "datum" won't be in the query string and you'll have to place it on the page again:
RegisterHiddenField( "datum", Request.Form["datum"] );
To retrieve the hidden value on the second page:
var datum = document.Form1.item("datum").value;
alert( datum );
You can easily submit a form on one page that points to another page using the action parameter. For instance, inside of page1.aspx put the following:
<form action="page2.aspx" method="GET">
<input type="hidden" name="username" value="joenobody" />
<input type="submit" />
</form>
Since you're using "GET" as the method instead of "POST", you could potentially use Javascript to parse the URL and get the value that was passed. Alternatively, you could use ASPX to store the value of the "username" field somewhere else on the page. I don't know ASPX (or ASP, or anything Microsoft really), but if you can find a way to output something like the following (and are using jQuery), it may do what you require. Honestly though, it sounds like you are going about something all wrong. Can you modify your question to be a bit more specific about what the general object is that you are attempting to accomplish?
<div id="some_div"><%= Request.form("username") %></div>
<script type='text/javascript'>
var value_needed = $('#some_div').html();
</script>
<form method="get">
Assuming you mean hidden in the HTML form sense, your field will be submitted along with all the other fields when the form is submitted. If you are submitting via GET, then your "hidden" field will show up in plain text in the URL. If you don't want the data in the hidden field to be accessible to users, don't put an understandable value in that field.
If you are using aspx, you do not need to parse the query string using JavaScript, or even use <form method="GET" ...>. You can POST the form to the second aspx page, extract the value in C# or VB then write it to a client-side JavaScript variable. Something like this:
page1.aspx:
<form method="POST" action="page2.aspx">
<input type="hidden" name="myHiddenServerField" value="myHiddenServerValue">
<input type="submit">
</form>
page2.aspx:
<script type="text/javascript">
var myHiddenClientValue = '<%= Request.Form['myHiddenServerField']; %>';
</script>
The above would set the client-side JavaScript variable called myHiddenClientValue to a value of 'myHiddenServerValue' after the POST.
This can be a bad idea because if myHiddenServerField contains single quotes or a newline character, then setting it on the client in page2.aspx can fail. Embedding ASP.NET Server Variables in Client JavaScript and Embedding ASP.NET Server Variables in Client JavaScript, Part 2 deals with specifically these issues, and solves them with a server-side class that ensures values being written to the client are escaped correctly.
If you use method="get" on an HTML form then any hidden inputs in that form will be converted to query parameters.
See also Jeremy Stein's answer.

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