Posting JSON with Knockout.

formpost.html

<form action="/tasks/saveform" method="post">
    <hidden name="tasks" data-bind="value: ko.toJSON(tasks)"></hidden >
    <button type="submit">Save</button>
</form>

save.js

self.save = function() {
  $.ajax("/tasks", {
      data: ko.toJSON({ tasks: self.tasks }),
      type: "post", contentType: "application/json",
      success: function(result) { alert(result) }
  });
};