Is There A Way To Tell Knockout To Wait To Recalculate Computed Values Until After The View Model Is Defined?

I have a complex view model which is a couple hundred lines of javascript code with a good amount of observable properties, computed observable properties, writable computed observ

Solution 1:

Computed observables accept a deferEvaluation option that prevents the initial evaluation from happening until something actually tries to retrieve the computed's value.

You would define it like:

self.fullName = ko.computed({
   read: function() {
       return self.firstName() + " " + self.lastName();
   },
   deferEvaluation: true
});

Just for completeness, you could also specify it like:

this.fullName = ko.computed(function() {
       return this.firstName() + " " + this.lastName();
 }, this, { deferEvaluation: true });

Or you could wrap it like:

ko.deferredComputed = function(evaluatorOrOptions, target, options) {
   options = options || {};

   if (typeof evaluatorOrOptions == "object") {
       evaluatorOrOptions.deferEvaluation = true;   
   } else {
       options.deferEvaluation = true;
   }

   return ko.computed(evaluatorOrOptions, target, options);
};