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Enable Two-Way data binding on Angular 6 for input type checkbox inside *ngFor

Problem: Two-way data binding for checkbox in *ngFor directive
I have a template driven form in which I am using *ngFor to loop over few radio buttons. Based on one key, I show checkbox next to radio buttons in disabled state on page load. If user clicks on a radio button and if it has a corresponding checkbox, I enable its state. I can then click on checkbox.
However, I want to be able to disable previous checkbox and reset its value when user clicks on another radio button and thus pass the correct form values. (I show them as json in beloe code demo url)
Demo code example: https://stackblitz.com/edit/angular-ba8pfz
If you see the demo code, I should be able to reset the checkbox if I toggle between "Marvel Heroes" and "Dc Heroes"
Appreciate your time and suggestions.

You cannot simply set the checked attribute to false as that sets the content checked attribute to an empty string - which is the equivalent of true or checked. Hence the check mark goes away, but the Boolean state of the control is not changed. Have to change the Boolean state of the control. One simple way to do that is to generate a click or change event on the control.
Try this:
enableRecursive(event, recursiveChk: boolean) {
let clickEvent = new MouseEvent('click');
this.recursiveChk.map((elem) => {
if (elem.nativeElement.checked) {
elem.nativeElement.dispatchEvent(clickEvent);
}
elem.nativeElement.disabled = true;
if (`recursive_${event.target.id}` === elem.nativeElement.id) {
elem.nativeElement.disabled = false;
}
});
}

Exclusive input checkboxes - enable to uncheck by clicking on current checked input

I did an exclusive menu of 2 input checkboxes : each input checkbox corresponds to a different case : (Player Vs Computer) and (Player1 Vs Player2) and each case is associated to 2 buttons (which work as I want).
My issue is that I would like to add a functionality, i.e enable to uncheck the current checked box by clicking on the current checkbox (this one which is already checked).
For the moment, I have to click directly on the other input checkbox to uncheck the current one; I would like to get the both functionalities.
Here's the current code which handles these 2 exclusive input checkbox :
// Check input checked
checkBoxState = $('#'+gameType+'').find('.game').prop('checked');
// Set oneButtonClicked to no for restore
$('#formGame').prop('oneButtonClicked', 'no');
// Handling input.game
$('#'+gameType+'').find('.game').prop('checked', !checkBoxState);
//$('#'+gameType+'').siblings().find('.game').prop('checked', checkBoxState);
// Set pointer-events to all for formGame
$('#formGame').css('pointer-events', 'all');
// Handling button.btn
$('#'+gameType+'').find('.btn').css('pointer-events', 'none');
$('#'+gameType+'').siblings().find('.btn').css('pointer-events', 'all');
$('#'+gameType+'').find('.btn').prop('disabled', checkBoxState);
$('#'+gameType+'').siblings().find('.btn').prop('disabled', !checkBoxState);
gameType is the current type of game (Player Vs Computer or Player1 Vs Player2).
input.game represent the input checkboxes
button.btnrepresent the 2 buttons available for each ìnput.game.
How can I add this functionality, i.e uncheck by clicking on current checked, or uncheck by clicking directly on the other checkbox?
Update 1
A click on a checkbox should automatically set its negation to the other checkbox.
Update 2
I tried to adapt the solution given by #CodeAt30 by doing simply:
gameType = (gameType == 'PlayerVsComputer') ? 'Player1VsPlayer2' : 'PlayerVsComputer';
$('#'+gameType).find('.game').prop('checked', !$('#'+gameType).find('.game').prop('checked'));
This solution works for uncheck the current checkbox and check its siblings().
But now, I can't select directly the other checkbox unlike to the JS Fiddle: Uncheck checkbox by clicking directly on the other no-checked "input checkbow"

https://jsfiddle.net/m059rr88/
HTML
<input id="one" type="checkbox"></input>
<input id="two" type="checkbox"></input>
Javascript:
let afterFirstClick = false;
$("input").click(function(){
let passiveCheckboxId = "one";
if($(this).attr("id") === "one"){
passiveCheckboxId = "two"
}
if(afterFirstClick){
$("input#" + passiveCheckboxId).prop("checked", !$("input#" + passiveCheckboxId).prop("checked"));
}
afterFirstClick = true;
});

Easier than you might think:
$('input.game').click(function(){
$('input.game').not(this).removeAttr('checked');
});
What is does is assign a click handler to the checkboxes that removes the checked attribute from all other boxes. The status of the current box is handled by the native checkbox code, so checking and unchecking will work normally.
... or ...
$('input.game').click(function(){
if (this.checked) {
$('input.game').not(this).removeAttr('checked');
} else {
$('input.game').not(this).trigger('click');
}
});
This code will allow you to swap checkboxes by clicking on either one. Once a box is checked there is no way to uncheck it, like a radio button.

jquery get value of checked radio button on load or change

Got this script that gets the value of a checked radio button and prints it out in another tag. It works perfectly when you click a radio button, but I've realized that I need to have some of the radio buttons checked by default.
How do I change this script so that it will output the values of already checked radio buttons on page load as well?
$("input[type='radio']").click(function(){
var radioValue = $(this).val();
if(radioValue){
$(this).closest('section').find('h2 .value').text(radioValue);
}
});
Fiddle: https://jsfiddle.net/tactics/bykf31e6/4/

You can use the :checked selector to find all the checked :radio elements on load, and the loop over them to set the value of the related .value element. Try this:
$(":radio:checked").each(function() {
$(this).closest('section').find('h2 .value').text(this.value);
});
Example fiddle
Note that you should use the change event for binding to radio and checkbox elements to cater for those who navigate websites using their keyboards. Also, if you remove the check that the radio element has a value (which is redundant as they should always have a value) you can simplify the code:
$("input[type='radio']").change(setText); // when user selects
$(":radio:checked").each(setText); // onload
function setText() {
$(this).closest('section').find('h2 .value').text(this.value);
}
Example fiddle

How do I keep a Checkbox disabled in Internet Explorer

I have an application that pairs a textbox with a checkbox. The user can check the checkbox, which auto-populates the textbox with a specific dollar amount. If they uncheck the checkbox, this sets the textbox's value to zero. They can also enter a dollar amount in the textbox and an onblur event handler toggles the checkbox.
The problem comes when they enter a dollar amount in the textbox and then check the checkbox with a mouse click. This fires the onblur event, which automatically toggles the checkbox, then recognizes the mouse click, setting the dollar amount back to zero.
My solution was to disable the checkbox on textbox focus, then enable the checkbox on textbox onblur event.
This works well in Firefox and Chrome, but fails miserably in Internet Explorer. FF and Chrome ignore any mouse click on the checkbox when it is disabled. This means that the onblur event does not fire, when the user clicks on the disabled checkbox after entering a dollar amount in the textbox. The checkbox stays disabled. They have to click elsewhere on the page for it to be enabled.
In Internet Explorer, the onblur event fires when the user clicks on the disabled checkbox, and the checkbox recognizes the click, right after it is checked with the onblur event handler, unchecking the checkbox, setting the textbox value back to zero.
I need a better solution. How do I get Internet Explorer to act like FF and Chrome, ignoring any click on a disabled checkbox. Or, is there a more elegant solution altogether?
Example Code:
<input type=textbox id=textbox1 onFocus=CheckboxDisable('pairedWithTextBox1'); onBlur=CheckboxEnable('pairedWithTextBox1');>
<input type=checkbox id=pairedWithTextBox1>
Javascript code:
function CheckboxDisable(id){
document.getElementById(id).disabled = true;
}
function CheckboxEnable(id){
document.getElementById(id).disabled = false;
}

Short of a real solution. .. you COULD set a data attribute on the check box on focus of the text element, then check for it on the cb on click event and override the default action. ..

Aside from a possibly confusing user interface design (can't say for sure since you genericized the problem too much), the problem is that the checkbox and textbox are both views of the same model.
The model is the dollar amount.
The textbox is a view of the
actual dollar amount.
The checkbox is a view that indicates
whether the amount is 0 or something else.
Your current design is complex, which is not by itself a bad thing, because the event handlers for the text box onblur and checkbox onclick are also controllers of the model. (This is a bit of an oversimplification; the controller also consists of the browser and all the JavaScript code.)
Here is a solution that helps illustrate this fact. It works based on the business rule that once the user has modified the value in the textbox (to a non-zero value) changing the state of the checkbox from unchecked to checked will not update the model (or the textbox view).
var txtAmount = document.getElementById('txtAmount');
var chkAmount = document.getElementById('chkAmount');
var defaultValue = 0;
var model = defaultValue;
function UpdateViews() {
if (model === 0) {
chkAmount.checked = false;
}
txtAmount.value = model.toFixed(2);
}
function UpdateModel(val) {
// update model when view changes
model = parseFloat(val) || defaultValue;
UpdateViews();
}
UpdateViews(); // set initial view
txtAmount.onchange = function () {
UpdateModel(this.value);
};
chkAmount.onclick = function () {
if (this.checked) {
// when user checks the box, only update model if not yet modified
if (model === defaultValue) UpdateModel(55); // hardcoded default of $55
} else {
UpdateModel(defaultValue);
}
};
<input type='text' id='txtAmount' />
<input type='checkbox' id='chkAmount' />

If I were in your case, I will put an If-Else in the click event of the checkbox...
Something like:
if (!String.IsNullOrEmpty(textBox1.Text) | textBox1.Text != "0")
{
// Do nothing since textbox1 already has a value greater than zero
}
else
{
// Enter amount in textbox
}

Try this..
function CheckboxDisable(id){
$("#id").attr("disabled", "disabled");
}
function CheckboxEnable(id){
$("#id").removeAttr("disabled");
}

How do I use jQuery to disable a form's submit button until every required field has been filled?

I have a form with multiple inputs, select boxes, and a textarea. I would like to have the submit button be disabled until all of the fields that I designate as required are filled with a value. And after they are all filled, should a field that WAS field get erased by the user, I would like the submit button to turn back to disabled again.
How can I accomplish this with jQuery?

Guess my first instinct would be to run a function whenever the user starts modifying any of the inputs. Something like this:
$('#submitBtn').prop('disabled', true);
$('.requiredInput').change(function() {
inspectAllInputFields();
});
We then would have a function that checks every input and if they're validated then enable the submit button...
function inspectAllInputFields(){
var count = 0;
$('.requiredInput').each(function(i){
if( $(this).val() === '') {
//show a warning?
count++;
}
if(count == 0){
$('#submitBtn').prop('disabled', false);
}else {
$('#submitBtn').prop('disabled', true);
}
});
}
You may also want to add a call to the inspect function on page-load that way if the input values are stored or your other code is populating the data it will still work correctly.
inspectAllInputFields();
Hope this helps,
~Matt

Here's something comprehensive, just because:
$(document).ready(function() {
$form = $('#formid'); // cache
$form.find(':input[type="submit"]').prop('disabled', true); // disable submit btn
$form.find(':input').change(function() { // monitor all inputs for changes
var disable = false;
$form.find(':input').not('[type="submit"]').each(function(i, el) { // test all inputs for values
if ($.trim(el.value) === '') {
disable = true; // disable submit if any of them are still blank
}
});
$form.find(':input[type="submit"]').prop('disabled', disable);
});
});
http://jsfiddle.net/mblase75/xtPhk/1/

Set the disabled attribute on the submit button. Like:
$('input:submit').attr('disabled', 'disabled');
And use the .change() event on your form fields.

Start with the button disabled (obviously). Bind an onkeyup event to each required text input, and an onchange or onclick to the select boxes (and any radio buttons/checkboxes), and when it fires, check whether all required inputs are filled. If so, enable the button. If not, disable it.
There is one loophole here, though. Users can delete the value of a text field without triggering the onkeyup event by using the mouse to "cut" the text out, or by holding down the delete/backspace key once they have deleted it all, and clicking the button before deleting it.
You can get around the second by either
disabling the button with onkeydown and checking if it is ok on onkeyup
checking for validity when the button is clicked

An idea from me:
Define a variable -with global scope- and add the value true- Write a submit function within your check the value above varibale. Evalue the the submit event only, if the value is true.
Write a function which ckecks all value from input fields and select fields. Checking the length of value to zero. if the value length of one field zero then change the value of the global variable to false.
After that, add to all input fields the event 'onKeydown' or 'onKeyUp' and to all select boxes the event 'onChange'.

I recommend taking a slightly different approach and using jquery's validation http://docs.jquery.com/Plugins/validation. The tactic you are suggesting is prone to security holes. The user could easily using firebug enable that button and then submit the form.
Using jquery validation is clean and it allows you to show error messages under the required fields if so desired on submit.