title: Referencing properties of object constructor outside view model in knockout
body: <p>So, I'm not entirely sure how to phrase this question as it's sort of two in one. I'm having a weird issue where I have an object constructor to create new 'projects' from an HTML form which are then pushed into an observableArray when the form is submitted. Everything works fine but to reference the related observables I have to use 'value: Project.title' or 'value: Project.whatever'. I haven't seen 'value: NameOfConstructor.property' used in any of the examples I've seen. I assume this works this way because the constructor is outside of my view model.</p>
  
  <p>My question is this: Is there a better way to assign the value of a property in a constructor that is not in my view model? In other words, is there a better or more correct way than 'Project.title', ect?
  I ask partially because one thing in my code doesn't work currently; the knockout enable property doesn't work on my "New Project" button, it stays disabled even if there is something written in the 'title' input box. I have the feeling it's because it's written as data-bind='enable: Project.title' but I can't figure how else to write it.</p>
  
  <p>I've included a jsfiddle for reference though it obviously isn't working because of external dependencies.
  <a href="https://jsfiddle.net/bmLh0vf1/1/" rel="nofollow">https://jsfiddle.net/bmLh0vf1/1/</a></p>
  
  <p>My HTML:</p>
  
  <pre><code>&lt;form id='addBox' action='#' method='post'&gt;
      &lt;label for='pTitle'&gt; Title: &lt;/label&gt;
      &lt;input id='pTitle' data-bind='value: Project.title' /&gt;
      &lt;br/&gt;
      &lt;label for='pPriority'&gt; Priority &lt;/label&gt;
      &lt;select id='pPriority' data-bind='options: priorityOptions, value: Project.priority'&gt;&lt;/select&gt;
      &lt;br/&gt;
      &lt;button data-bind='enable: Project.title, click: newProject'&gt;New Project&lt;/button&gt;
    &lt;/form&gt;
  </code></pre>
  
  <p>And my Javascript:</p>
  
  <pre><code>function Project(title, priority) {
    this.title = ko.observable(title);
    this.priority = ko.observable(priority);
  };
  
  
  function ProjectViewModel() {
    var self = this;
    this.priorityOptions = ko.observableArray(['High', 'Medium', 'Low'])
    this.projectList = ko.observableArray([
      new Project('Create App', 'High')
    ]);
    this.newProject = function() {
      var np = new Project(Project.title, Project.priority);
      self.projectList.push(new Project(Project.title, Project.priority));
      console.log(self.projectList().length);
      if (self.projectList().length &gt; 1) {
        console.log(self.projectList()[1].title());
      };
    }
  };
  
  var viewModel = new ProjectViewModel();
  $(document).ready(function() {
    ko.applyBindings(viewModel);
  });
  </code></pre>
  
  <p>Lastly, I apologize if I've missed any posting conventions or if my code is especially bad. I'm very new and still teaching myself.</p>