ModelJS firstName lastName

This is a simple example that uses Model.js to update a "lastName" property based on properties "firstName" and "lastName" using forms.

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>ModelJS Example</title>
    <script src="//cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js"></script>
    <script src="model.js"></script>
    <style>
      body {
        margin: 220px;
      }
    </style>
  </head>
  <body>
    <form>
      First name: <input type="text" id="firstNameInput"><br>
      Last name:  <input type="text" id="lastNameInput"><br>
      Full name: <span id="fullNameSpan"></span>
    </form>
    <script>
      var model = Model({
        firstName: "",
        lastName: ""
      });

d3.select("#firstNameInput").on("input", function (e){
        model.firstName = this.value;
      });

d3.select("#lastNameInput").on("input", function (e){
        model.lastName = this.value;
      });

model.when(["firstName", "lastName"], function (firstName, lastName){
        model.fullName = firstName + " " + lastName;
      });

model.when("fullName", function (fullName){
        d3.select("#fullNameSpan").text(fullName);
        console.log("Full name updated.");
      });

</script>
  </body>
</html>

https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js