Checked binding not working when click returns false

Question

I have problem with checked and click binding.

I want to have check-listbox for selection multiple rows, and I want to be able to reject unselect last value.

The best what i can get is this.

There is problem, that when i click the last checkbox it will not unselect, but checked binding will still remove the last value from array.

Please help with any solution.

HTML:

<div id="bookingResources" class="listcontrol">
  <!-- ko foreach:resources -->
  <div class="li" data-bind="css:{ 'selected':$root.isResourceSelected($data) }">
    <a href="#" data-bind="click:$root.selectResource">
      <span data-bind="text:Name"></span>
      <input class="right" type="checkbox" data-bind="click:$root.checkboxClick, clickBubble:false, value:Id, checked:$root.resourceIds"/>
    </a>
  </div>
  <!-- /ko -->
</div>

JS:

var model = function(){
    var self = this;

  self.resources = [{"Id":4612,"Name":"John"},{"Id":4613,"Name":"Tom"},{"Id":4614,"Name":"Marty"}];

  self.resourceIds = ko.observableArray([4612]);

    self.isResourceSelected = function(resource) {
            return self.resourceIds.indexOf(resource.Id) >= 0;
    }

    self.selectResource = function (resource) {
        if (self.isResourceSelected(resource)) {
            if (self.resourceIds().length > 1) { // the last not remove
                self.resourceIds.remove(resource.Id);
            }
        } else {
                self.resourceIds.push(resource.Id);
        }
    }

  self.checkboxClick = function(resource) {
    if (self.resourceIds().length != 1)
      return true;

    return self.resourceIds()[0] != resource.Id;
  }

  //subscribe
  self.resourceIds.subscribe(function(newValue) {
    console.log("Selected resorces (" + newValue.length + "): " + newValue);
  });
}

ko.applyBindings(new model(), document.getElementById("bookingResources"))

Answer 1

Ok, I searched through the knockout source code of checked binding and found, that it is simply binding click event HERE.

So i needed only jquery to stop eventPropagation on the checkbox element. Calling event.stopimmediatepropagation() should do the work.

Together I can stop event propagation, so checked binding will not process current click:

self.checkboxClick = function(resource, event) {
    if (self.resourceIds().length != 1)
        return true;

    if(self.resourceIds()[0] == resource.Id)
    {
        event.stopImmediatePropagation();
        return false;
    }

    return true;
}