Networking with JSON and Java

index.html

User name: 
<form>
<input data-bind="value: user, valueUpdate: 'afterkeydown'"
  placeholder="Your own? Or try 'tmysik'">
</input> 
<input type="submit" data-bind="click: computeGists, enable: validUser" value="Show!">
</form>

<h3><span data-bind="text: user"></span>'s Code Snippets</h3>

<!-- iterate through list of Gists and show their id and description -->
<ul data-bind="foreach: gists">
  <li>
    <span data-bind="text: id"></span> -
    <a data-bind="attr: { href: html_url }, text: description" target="gists">
    </a>
  </li>
</ul>

ListGists.java

package dew.demo.gists;

import java.util.Arrays;
import net.java.html.json.*;

@Model(className="UI", properties={
  @Property(name="user",type=String.class),
  @Property(name="gists",type=Gist.class, array = true)
})
class ListGists {
  /** Generates class Gist which is a Java representation
  * of appropriate JSON object send from the server.
  */
  @Model(className="Gist", properties={
    @Property(name="id", type=String.class),
    @Property(name="url", type=String.class),
    @Property(name="html_url", type=String.class),
    @Property(name="description", type=String.class)
  })
  static class GistImpl {
  }
  
  @ComputedProperty static boolean validUser(String user) {
    return user != null && !user.isEmpty();
  }
  
  /** Generates method <b>gists</b> into the associated model
  * class UI which connects to here in specified URL, obtains
  * results (asynchronously) and when list of gists is here,
  * calls back to this method.
  */
  @OnReceive(url = "https://api.github.com/users/{user}/gists")
  static void gists(UI ui, Gist[] gists) {
    // replace list of gists with new list
    ui.getGists().clear();
    ui.getGists().addAll(Arrays.asList(gists));
  }
  
  @Function static void computeGists(UI model) {
    // when Show! button is pressed, query for gists of specified user
    model.gists(model.getUser());
  }
  
  static {
    UI m = new UI();
    m.applyBindings();
  }
}