Initialize Knockout observable from element attribute value

Question

I have an element that possesses an attribute whose value is bound to a knockout observable:

Answer 1

Another option would be to use a custom binding, and collect the current value of the element in the init function. This is much more reusable, in my opinion.

ko.bindingHandlers.transform = {
    init: function(element, valueAccessor) {
        valueAccessor()(element.getAttribute('transform'));
    },
    update: function(element, valueAccessor) {
        var value = valueAccessor();
        element.setAttribute('transform', ko.utils.unwrapObservable(value))
    }
};

Of course, yours will be more complicated, since you must be doing something with this transform property. That logic will probably want to go in the update section.