how to clear validation errors for Angular Material mat-error - angular-material2

I'm trying to reset a form after I've added a value.
Form Code Snippet
<form [formGroup]="addAttributeForm" fxLayout="column">
<mat-form-field>
<input matInput formControlName="title" placeholder="Title" required>
<mat-error>This field is required</mat-error>
</mat-form-field>
</form>
In the component
onSubmit(form: FormGroup) {
// do work
form.reset();
}
What I'm observing:
The form values are set to empty.
But the validation messages are still displayed from mat-error.
I've tried form.markAsPristine(), form.markAsUntouched() and combining all three.
How can I reset the form so the mat-error is not displayed?

The form group has no "knowledge" about whether the actual HTML form has been submitted or not. It only keeps track of the form values/validity/enabled state. So resetting the form group does reset the values but not any state regarding whether the form has been submitted.
To do this, you need to get a hold of the FormGroupDirective and call resetForm() on it.
Form Code Snippet
<form [formGroup]="addAttributeForm" fxLayout="column">
<!-- ... -->
</form>
In the component
#ViewChild(FormGroupDirective) formDirective: FormGroupDirective;
onSubmit(form: FormGroup) {
// do work
this.formDirective.resetForm();
}

This solution works with me.
You need to do next:
formReset(form: FormGroup) {
form.reset();
Object.keys(form.controls).forEach(key => {
form.get(key).setErrors(null) ;
});
}
This reset the form and clear all error.

The only way I've been able to successfully do this is by setting a flag to hide the form when you want to reset it and then using a timeout to set that flag back to true. As far as I know, there is no built-in way to do this yet.
showForm = true;
reset(): void {
this.showForm = false;
setTimeout(() => this.showForm = true);
}
And then in the HTML on the form element use *ngIf="showForm".

Related

Resetting a form generated server-side in vue.js

I am rendering a form with Blade, Laravel's server-side templating language. The default values for the form elements are assigned by Blade. There is no JavaScript involved until now. Now I want to implement a reset button.
When a user presses the reset button the form should be cleared. A simple HTML reset button is not sufficient as it would not reset the "value=something" default values to "null".
In other words:
<input type="text" name="fullname" value="John Doe">
is supposed to be
<input type="text" name="fullname" value="">
after the user pressed the reset button.
With JQuery I would do something like this:
$("body").find('form').find('input').val('');
How can I do it with vue.js? Adding av-model and setting the v-model properties to null interferes with the server side default values...
In general: would you suggest to add a DOM manipulating lib to the application for such "hybrid" use cases where vue.js does not control the data?
If you plan on using vue, forget about altering the dom, vue works around states so imagine your input is like this
<input type="text" v-model="test_input">
and when you change the variable test_input the input automaticly changes its value, so just set it to empty in a method.
<button #click="clear_form"> Clear </button>
<script>
export default {
data() {
return {
test_input : ''
}
},
methods:{
clear_form(){
this.test_input = '';
}
}
}
</script>
I ended up writing a reset-form button component. In this component I use plain Javascript to get all input, select, ... fields of the form identified by an id and reseted the values to ''.
I took this option as it was the fastest way to reset the form and I don't have to change anything (e.g. add props, change ajax calls) if my form changes.

How to clear jquery validate errors

I'm hijaxing an existing form and POSTing to the server. jQuery validate does most of the validation but if validation fails on the server we return the errors to the client as JSON.
Below is the code that does that:
<script type="text/javascript">
$(function () {
$("form").submit(function (e) {
var $form = $(this);
var validator = $form.data("validator");
if (!validator || !$form.valid())
return;
e.preventDefault();
$.ajax({
url: "#Url.Action("index")",
type: "POST",
data: $form.serialize(),
statusCode: {
400: function(xhr, status, err) {
var errors = $.parseJSON(err);
validator.showErrors(errors);
}
},
success: function() {
// clear errors
// validator.resetForm();
// just reload the page for now
location.reload(true);
}
});
});
});
</script>
The problem is I can't seem to clear the validation errors if the POST is successful. I've tried calling validator.resetForm() but this makes no difference, the error messages added by the showError() call, are still displayed.
Note I'm also using the jQuery.validate.unobtrusive plugin.
You posted this a while ago, I don't know if you managed to solve it? I had the same problem with jQuery validate and the jQuery.validate.unobtrusive plugin.
After examining the source code and some debugging, I came to the conclusion that the problem comes from the way the unobtrusive plugin handles error messages. It removes the errorClass that the jQuery.validate plugin sets, and so when the form is reset, jQuery validate cannot find the error labels to remove.
I did not want to modify the code of the plugins, so I was able to overcome this in the following way:
// get the form inside we are working - change selector to your form as needed
var $form = $("form");
// get validator object
var $validator = $form.validate();
// get errors that were created using jQuery.validate.unobtrusive
var $errors = $form.find(".field-validation-error span");
// trick unobtrusive to think the elements were succesfully validated
// this removes the validation messages
$errors.each(function(){ $validator.settings.success($(this)); })
// clear errors from validation
$validator.resetForm();
note: I use the $ prefix for variables to denote variables that contain jQuery objects.
$("#form").find('.field-validation-error span').html('')
In .NET Core I have the form inside a builtin Bootstrap modal.
For now I'm manually removing the error message spans from their containers, once the modal is starting to show, by using the additional .text-danger class of the error message container like so:
$('#my-form').find('.text-danger').empty();
so that I don't rely on container .field-validation-error that might have been already toggled to .field-validation-valid.
The min.js versions of the libraries jquery.validate and jquery.validate.unobtrusive are loaded via the partial view _ValidateScriptsPartial.cshtml, so I played with them to see what resetForm() / valid() and native html form reset() do.
So in my case $('#my-form').data("validator").resetForm() only resets some validator internals, not the form and it doesn't trigger the onReset() function in the unobtrusive library. The $('#my-form').valid() indeed removes the errors in the modal, but only if the modal is fully shown and valid. The native html form reset() is the only one that triggers both onReset() of unobtrusive library, and then the resetForm() of the validator. So it seems like we need to trigger the native html form document.querySelector('#my-form').reset() to activate the reset functions of both libraries/plugins.
The interesting thing is that the unobtrusive library runs the simple jQuery empty() on the .field-validation-error class (the container of the error span message) only in its onSuccess() function, and not onReset(). This is probably why valid() is able to remove error messages. The unobtrusive onReset() looks like it's responsible only for toggling .field-validation-error class to .field-validation-valid. Hense we are left with a <span id="___-error">The error message</span> inside the container <span class="text-danger field-validation-error">...</span>.
May be I am wrong to clear the errors like this:
function clearError(form) {
$(form + ' .validation-summary-errors').each(function () {
$(this).html("<ul><li style='display:none'></li></ul>");
})
$(form + ' .validation-summary-errors').addClass('validation-summary-valid');
$(form + ' .validation-summary-errors').removeClass('validation-summary-errors');
$(form).removeData("validator");
$(form).removeData("unobtrusiveValidation");
$.validator.unobtrusive.parse($(form));
};
I tried answer given in the comment by AaronLS but not got the solution so I just do it like this.
Maybe helpful to someone.
Here's the code I ended up using to clear/reset all errors. It's possible there's some redundancy in there, but it's working for me.
function removeValidationErrors(frmId) {
var myform = $('#' + frmId);
myform.get(0).reset();
var myValidator = myform.validate();
$(myform).removeData('validator');
$(myform).removeData('unobtrusiveValidation');
$.validator.unobtrusive.parse(myform);
myValidator.resetForm();
$('#' + frmId + ' input, select').removeClass('input-validation-error');
}
The reason this is still an issue (even 6 years on) is that jQuery Validation doesn't have an event handler for when your form is valid; only for when it's invalid.
Unobtrusive Validation taps into the Invalid handler to add your errors to your Validation Summary elements. (Specifically, any element with data-valmsg-summary=true.) But because there's no Valid handler, there's no way for Unobtrusive Validation to know when they can be cleared.
However, jQuery Validation does allow you to supply your own showErrors method, which is called after every validation check, whether the result is valid or invalid. Thus, you can write a custom function that will clear those validation summary boxes if your form is valid.
Here's a sample that will apply it globally. (You could apply it to specific instances of your validators by using settings, but since I always want this functionality, I just put it in the defaults object.)
$.validator.defaults.showErrors = function () {
if (!this.errorList.length) {
var container = $(this.currentForm).find("[data-valmsg-summary=true]");
container.find("ul").empty();
container.addClass("validation-summary-valid").removeClass("validation-summary-errors");
}
// Call jQuery Validation's default showErrors method.
this.defaultShowErrors();
};
This also has the benefit of clearing the validation summary box the moment your form is valid, instead of having to wait for the user to request a form submission.
I couldn't find this documented anywhere, but you should be able to reset the form by triggering a specific event, reset.unobtrusiveValidation, to which unobtrusive listens.
Example here:
.validation-summary-valid, .field-validation-valid { display: none; }
.field-validation-error { display: block; color: #dc3545 }
.input-validation-error { border: 1px solid #dc3545 }
.validation-summary-errors { background-color: #dc3545; color: #fff; margin-bottom: .5rem; }
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.19.5/jquery.validate.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery-validation-unobtrusive/4.0.0/jquery.validate.unobtrusive.js"></script>
<form id="testForm">
<div class="validation-summary-valid" data-valmsg-summary="true">
Validation Summary:
<ul><li style="display:none"></li></ul>
</div>
<div>
<label for="first_name">first name:</label>
<input data-val="true" data-val-required="the 'first name' field is required" name="first_name" id="first_name" />
<span class="field-validation-valid" data-valmsg-for="first_name" data-valmsg-replace="true"></span>
</div>
<div>
<label for="last_name">last name:</label>
<input data-val="true" data-val-required="the 'last name' field is required" name="last_name" id="last_name" />
<span class="field-validation-valid" data-valmsg-for="last_name" data-valmsg-replace="true"></span>
</div>
<button type="submit">Submit form (click first)</button>
<button type="button" onclick="$('#testForm').trigger('reset.unobtrusiveValidation')">Reset form (click second)</button>
</form>

jQuery.validate stops my form from being submitted

jQuery.validate stops my form from being submitted. I would like it to just show the user what is wrong but allow them to submit anyway.
I am using the jquery.validate.unobtrusive library that comes with ASP MVC.
I use jquery.tmpl to dynamically create the form and then I use jquery.datalink to link the input fields to a json object on the page. So my document ready call looks something like this.
jQuery(function ($) {
// this allows be to rebind validation after the dynamic form has been created
$("form").removeData("validator");
$("form").removeData("unobtrusiveValidation");
$.validator.unobtrusive.parse($("form"));
// submit the answers
$("form").submit(function(e) {
$("input[name=jsonResponse]").val(JSON.stringify(answerArray));
return true;
});
}
I note that there is an option
$("form").validate({ onsubmit: false });
but that seems to kill all validation.
So just to recap when my form is rendered I want to show all errors immediately but I don't want to prevent the submit from working.
So after some research (reading the source code) I found I needed to do 2 things
add the class cancel to my submit button
<input id="submitButton" type="submit" class="cancel" value="OK" />
This stops the validation running on submit.
To validate the form on load I just had to add this to my document ready function
$("form").valid();
Hope this helps someone else

How can I stop a form from processing/submitting that is using jquery AJAX submission?

I have a form with two buttons, a submit button and a cancel/close button. When the user clicks submit, the entered data is validated using http://www.position-absolute.com/articles/jquery-form-validator-because-form-validation-is-a-mess/. If everything validates, the form is submitted with jQuery/AJAX. That all works fine and dandy. I run into problems with the cancel button though. I want the cancel button to require confirmation. If the user chooses to proceed, they are taken to a page of my choosing. If they decide they don't want to cancel, then they are simply left on the page. It's the last part that isn't working.
My form code looks like this:
<form name="createPage" id="createPage" method="post" action="pager.php" class="ajax updateForm">
<input name="whatever" type="text" />
<button type="submit" id="submitQuickSave" class="submitSave"><span>save</span></button>
<button type="submit" id="submitCancel" class="submitClose" onclick='confirm_close()'><span>close</span></button>
</form>
My current cancel script looks like the following. If the user does indeed want to cancel, I unbind the form submit so that validation isn't executed. The form then proceeds to submit and includes cancel as a parameter in the action attribute. I handle the cancellation server side and direct the user to a new page.
function confirm_close()
{
var r=confirm("All changes since your last save operation will be discarded.");
if (r==true)
{
$(".ajax").unbind("submit");
}
else
{
}
}
I cannot figure out what to put in the 'else' argument. What happens is that if the users cancels the cancellation (i.e., return false), then the form still tries to submit. I cannot make it stop. I've tried several things from this site and others without success:
event.stopImmediatePropogation
.abort()
Any ideas? Basically, how can I get the cancel/close button work properly?
Consider separating your JavaScript from your HTML. With this in mind, you could write the handler for your the click event you're trying to intercept like this:
$("button#cancel").click(function($event) {
var r = confirm("All changes since your last save operation will be discarded.");
if (r) {
$(".ajax").unbind("submit");
}
else {
$event.preventDefault();
}
});
You would have to tweak your HTML and add an id attribute to the cancel button:
<button id="cancel" type="submit" value="cancel">Cancel</button>
Example here: http://jsfiddle.net/wvFDy/
Hope that helps!
I believe you just
return false;
Let me know if this works.

how to create an function using jquery live?

I am writing a function that well keep the user in lightbox images while he adds to cart.
When you click any image it well enlarge using lightbox v2, so when the user clicks the Add image, it will refresh the page. When I asked about it at jcart support they told me to use jquery live, but I dont know how to do that. T tried this code but still nothing is happening:
jQuery(function($) {
$('#button')
.livequery(eventType, function(event) {
alert('clicked'); // to check if it works or not
return false;
});
});
I also used
jQuery(function($) {
$('input=[name=addto')
.livequery(eventType, function(event) {
alert('clicked'); // to check if it works or not
return false;
});
});
yet nothing worked.
for code to create those images http://pasite.org/code/572
I also tried:
function adding(form){
$( "form.jcart" ).livequery('submit', function() {var b=$(this).find('input[name=<?php echo $jcart['item_id']?>]').val();var c=$(this).find('input[name=<?php echo $jcart['item_price']?>]').val();var d=$(this).find('input[name=<?php echo $jcart['item_name']?>]').val();var e=$(this).find('input[name=<?php echo $jcart['item_qty']?>]').val();var f=$(this).find('input[name=<?php echo $jcart['item_add']?>]').val();$.post('<?php echo $jcart['path'];?>jcart-relay.php',{"<?php echo $jcart['item_id']?>":b,"<?php echo $jcart['item_price']?>":c,"<?php echo $jcart['item_name']?>":d,"<?php echo $jcart['item_qty']?>":e,"<?php echo $jcart['item_add']?>":f}
});
return false;
}
and it seems to add to jcart but yet it still refreshes
.live() is to assign handlers to future creating elements. On your site, however, you are re-loading the page so .live would have no bearing. (you are submitting a form)
It sounds like you want to make an ajax request to add the item to the cart and update that display on the site? That would be in the submit of the form and if jcart is dynamically created then yes, live is the answer.
$('.jcart').live('submit', function() {
// aggregate form elements into object and send via ajax
// update the cart on the page, since we haven't reloaded the page the light box is still displayed
});
Regarding comment:
When you send an ajax request, jquery takes an object as an argument. Such as $.post('urlToPostTo.php', { title: 'title of whatever', id: 5 } );
The server sees this the same as:
<form id="myForm" action="uroToPostTo.php" method="POST" >
<input type="text" name="title" value="title of whatever" />
<input type="hidden" name="id" value="5" />
<input type="submit" name="submit" value="submit" />
</form>
So if you were to aggregate the form inputs into an object, there's a few ways (even some jquery plugins to help you out). The primitive way would be:
var $form = $('#myForm'); // instead of finding myForm over and over, cache it as a variable to use
var objToSend = {};
objToSend.title = $form.find('input[name=title]').val();
objTosend.id = $form.find('input[name=id]').val();
$.post( 'urlToPostTo.php', objToSend );
A more Elegant solution is to have something loop through all form elements and put them into an object for you. Plugins like http://docs.jquery.com/Plugins:Forms make that a bit easier.
The end result is the form elements are stuffed into an object to send to your script.

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