Radio button intercepting unchecked event in Angular/Javascript - javascript

I am writing an Angular component which uses radio button (Need to use default radio buttons due to project constraints).
I need to print the value of the radio button (whether it is checked or unchecked). Like following:
<input type="radio" (change)="onUpdate($event)">
<p>{{isActive}}</p>
In the component something like this:
onUpdate(event) {
this.isActive = event.target.checked;
}
But this doesn't work as the change event is not triggered when the radio button is unchecked. Is there any way to intercept the event when the radio button is unchecked?
Please help. I am stuck. Dummy app link here
Edit: What I am trying to do
I am trying to write a custom radio button so that I can styles it on my own. I cannot write a radio-group component. Hence I need a wrapper component around the default one. Something like Stackblitz-link. I need the unchecked event because I have some custom element which has to be notified about this. Any way to achieve this ?

Use a checkbox, style it like a radio button. Seems to be the easiest solution and of course use ng-model instead of onChange.

You could replace (change) with (click), because every click on the radio button is a change anyway.
<input type="radio" (click)="onUpdate($event)">
<p>{{isActive}}</p>
The above is a solution, but I'd use this:
<input type="radio" [(ngModel)]="isActive">
<p>{{isActive}}</p>
It binds your radio button to your isActive property, so it changes dynamically with clicking.

So using two radio buttons got this working for me, let me know if you can model this for your application.
<input type="radio" name="button" [value]="checked" (change)="checked=!checked">
<input type="radio" name="button" [value]="!checked" (change)="checked=!checked">
<p>{{checked}}</p>
I am setting checked to false by default in my component.

Can you please try to adjust this logic with your code? Checking some new radio will uncheck other and we can keep track of this behavior.
<p>
<input type="radio" name="r1" value="one" [(ngModel)]="isActive">
<input type="radio" name="r2" value="two" [(ngModel)]="isActive">
<input type="radio" name="r3" value="three" [(ngModel)]="isActive">
</p>
<p>{{isActive}}</p>
Stackblitz link

Related

How can i create HTML5 like required alert for radio button?

For the input type text, if i add required attribute, my form won't submit and browser will focus on required field and alert will say please fill this field.
For the input type radio, if i add required attibute, my form won't submit but also it does not provide me any alert or focus on the radio which is unchecked.
If this is not an in-built functionality for HTML5, can i in some way create it and make it look like the same as it looks for text inputs so that style integrity is also preserved?
This code works well, if you not select radio, form will not submit. If you select one and enter text in textbox, form will submit.
<form>
<input type="radio" name="one" value="1" required>
<input type="radio" name="one" value="2" required>
<input type="radio" name="one" value="3" required>
<input type="text" name="two" required>
<button>Submit</button>
<form>
Checked on latest version of Google Chrome. May be you found a bug in your browser, try to update it.
Beside required radio button alerts work "perfectly fine" in Chrome...
jsBin demo
it makes no sense at all to have an alert for a radio button, that's silly.
If you have a radio button:
there's absolutely no need to have only one radio button. → Use checkboxes.
there's absolutely no reason to have all radio buttons unchecked initially.
one must be checked by default - and it's your job to do so
logically there's no need to popup alerts like "This radio button is required" - therefore neither to set a required attribute to a radio button.
if you still don't understand why... well simple because radios are used as UI switch states. Only one can and must be checked. If you make them all initially unchecked - and a client unintentionally hits a radio - he's dead in the devil's loop, because once you enter the circle there's no way out. Therefore makes no sense to have all blanks in the first place. You cannot undo... (well, unless you have another silly checkbox or something that says "uncheck all radio buttons!" nonsense).

selecting radio options doesnt change checked attribute

I am generating an HTML form with some radio buttons and checkboxes. the generated code for the radio buttons for instance are like these:
<input id="101_2" type="radio" name="101" value="2" >
<input id="101_3" type="radio" name="101" value="3" checked="true">
Using JavaScript I can make a for cycle to see what radio is checked using the check attribute.
The problem is that if I manually click in another radio option (from the same group as in the example), visually in the HTML I can see that another radio is selected, but the JavaScript is still saying that the input 101_3 is the selected radio option. If I look at the HTML using firebug I can see that the new selected option is indeed not selected (doesn't have the checked attribute)... despite I have selected manually.
Any ideas on this?
Fist and formost when naming your radio buttons or any type of DOM input element never start the name of an input element with a number, always start the name of your input element with a letter.
For your posted code you would name your radios in similar fashion, one01 or x101 or o101,ect...
Do the same thing with your ids' of any DOM element. Never start an id of a DOM element with a number.
--HTML
<input id="x101_2" type="radio" name="x101" value="2">
<input id="x101_3" type="radio" name="x101" value="3" checked="checked">
<br /><br />
<button type="button" onclick="WhatsChecked()">Whats Checked?</button>
--JavaScript
function WhatsChecked() {
var radCk = document.body.querySelectorAll('input[name="x101"]:checked')[0];
alert(radCk.id);
};
--Fiddler
fiddler

Grouped radiobuttons check changed

I am currently working on a project where we render a dynamic page based on what we are holidng in a SQL table. We have conditional validation for controls where you can say
if x is equal to y then enable controls abc
I have multiple radio buttons in a group, the last control is "Other (please specify)" which when true will enable a textbox to specify so I need to capture when this is set to both true or false. Currently I am doing something like this
<input type="radio" name="test" value="Yes" />
<input type="radio" onchange="onChange()" name="test" value="No" />
<script type="text/javascript">
function onChange() {
alert('Changed')
}
</script>
If I check NO I get an alert. If I then check YES it changes the NO radio button checkstate but doesn't display an alert - any solutions?
The only thing I can suggest is putting an onchange on the whole group and then checking which is selected when they change. Not very elegant but it appears that this is just how the change event works (ie it only responds to a user change, not to a system change of it).

getting class attribute of radio button in IE

I need to get the class attribute of checked radio button, with name="radio".
Used the code that's working fine in Firefox, but fails in IE.
val = $('input:radio[name=radio]:checked').attr('class');
How can i accomplish this?
There is no psuedo-class :radio. I think you meant [type=radio].
As comments says, I think you should use type instead of name. But i think you have named your input as radio because you can find this specific input. If you just use type selector you will catch every single selected radio input on page.
<input type="radio" name="radio" class="ey" /> Male<br />
So, if your page have more forms, you should specify a parent or form to avoid conflicts. Set a id for your form and try to find it by form id and radio type like this:
<form id="myForm">
<input type="radio" name="radio" class="ey" /> Male<br />
</form>
val = $("#myform input[type='radio']:checked").attr('class');
I hope it can help you :)

How do I make the "value" of the <input type="radio"> invisible?

<input type="radio" value="1" id="baby">
I'd like to keep this code like that.
However, can I apply a CSS to it so that the "1" is not displayed to the user?
Edit: For some reason, it is being displayed, I don't know why.
I do have a CSS attached to it though.
The value of "1" is not displayed to the user at all, it's hidden and only has meaning when the form posts. You need to add a <label> tag or just raw text near the radio button to display the value you want the user to see.
For radio buttons, the value attributed is never rendered by the user agent (unless it does something rather weird). Typically, if you need a radio button with a label, you explicitly specify one, ideally using the <label> tag.
The "1" should not display for the user.. it's just a value..
Normally, you'd declare a radio input like so:
<label><input type="radio" value="1" id="baby"> Baby </label>
This will make "Baby" the label for the radio button, this will also make clicking on the Baby text activate the radio button, which is what accessibility rules would require..

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