knockout.js bind to static data

Question

What's the suggested way to bind to existing static data? I have to include this in the viewmodel because its used in computed values.

http://jsfiddle.net/z2ykC/4/

<div id="sum" data-bind="text: sum">
</div>
<div class="line">
    dynamic: <span data-bind="text: dynamicValue"></span>
    static: <span data-bind="text: staticValue">312</span>
    <button data-bind="click: getDataFromServer">get data</button>
</div>
<div class="line">
    dynamic: <span data-bind="text: dynamicValue"></span>
    static: <span data-bind="text: staticValue">123</span>
    <button data-bind="click: getDataFromServer">get data</button>
</div>

​

function SumViewModel(lines){
    this.sum = ko.computed(function(){
        var value = 0;
        $.each(lines, function(index, element){
            var staticValue = element.staticValue();
            if (staticValue)
                value += staticValue;
            var dynamicValue = element.dynamicValue();
            if (dynamicValue)
                value += dynamicValue;
            value += dynamicValue;
        });
        return value;
    });
}

function LineViewModel() {

    this.randomNumber = function(max) {
        return Math.floor((Math.random() * max) + 1);
    };

    this.dynamicValue = ko.observable(0);
    this.staticValue = ko.observable();

    this.getDataFromServer = function() {
        this.dynamicValue(this.randomNumber(300));
    };

};

var lines = [];
$('.line').each(function(index, element) {
    var line = new LineViewModel()
    //line.staticValue(parseInt($('[data-bind*="staticValue"]', element).text()));
    lines.push(line);
    ko.applyBindings(line, element);
});
var sum = new SumViewModel(lines);
ko.applyBindings(sum, $('#sum')[0]);

​

Answer 1

You could look at creating a custom binding, which would initialize the staticValue observable. Here is a working fiddle:

http://jsfiddle.net/z2ykC/6/