Knockout firing click binding on applyBindings

Question

Recently I\'ve separated out ViewModel to a separate JavaScript file.

var Report = (function($) {
    var initialData = [];
    var viewModel = {
        rep         


        

Answer 1

The reason is, that you're indeed invoking the preview function (because writing functionName means referring to the function, writing functionName() means calling it).

So data-bind="click: Report.preview" would be working as expected, but without handing over the parameter.

As the manual states (on a different topic, but this still applies):

If you need to pass more parameters, one way to do it is by wrapping your handler in a function literal that takes in a parameter, as in this example:

<button data-bind="click: function(data, event) { myFunction(data, event, 'param1', 'param2') }">
    Click me
</button>

or in your case:

data-bind="click: function() { Report.preview('url/to/report') }"

Another solution would be to make preview() return a function (pretty much the same thing actually):

preview: function(path) {
    return function() {
        // ...
    }
}

Answer 2

Another solution is to use 'bind' construct:

data-bind="click: Report.preview.bind($data, 'url/to/report')" 

where the first parameter to bind() will become the 'this' in the called function.