CheckBox not getting checked in Knockoutjs

Question

I am using a checkbox with a function inside the data-bind, but I am unable to check the checkbox.

view:

<input type="checkbox" data-bind="click: function(){ f('hello parameter'); }">Click me

View Model:

var VM = function () {
    this.f = function (param) {
        alert(param); // here i am getting 'hello parameter'
        return true;
    }
}

ko.applyBindings(new VM());

Here is my Fiddle

Answer 1

By default, the click binding prevents the default reaction to a click based on the assumption that your JavaScript click event handler will handle everything. You need to return "true" to get the default behavior anyway, which you are doing from your f() function but not the wrapper inside data-bind:

<input type="checkbox" data-bind="click: function() { f('hello parameter'); }">

should be

<input type="checkbox" data-bind="click: function() { return f('hello parameter'); }">