tailieunhanh - developing facebookbapplications phần 6

Cùng với hành động, biểu đồ cũng có thể chứa một liên kết trợ giúp. Theo mặc định, các liên kết trợ giúp được đặt trên phía bên phải của bảng điều khiển. Bạn có thể xem những gì trông giống như trong hình 5,8. Các hành vi như là một thay thế cho khu vực để điều hướng | Hiding Content from Users 97 Profile edit Friends Networks V Inbox home account privacy logout H Invite your friends Help Feedback karatepoke Your Battles V Help Feedback Figure A dashboard with an action and a help link Along with actions dashboards can also contain a help link. By default help links are placed on the right side of the dashboard. You can see what this looks like in Figure . The fb dashboard acts as an alternative to the fb tab area for navigation. I prefer the tabs for navigation so let s remove the help link and action from our dashboard. We ve made some really small changes to our application that add a lot of style. We ll continue to look at other ways of adding style to our application throughout the rest of this book. Let s move on to looking at some more functional parts of the Facebook canvas. Hiding Content from Users As we develop Karate Poke we ll run into situations where we want to show content to only certain users. Facebook provides a number of powerful tools to make it easier to handle these cases. We ll see an example of how to use these tools here. We re going to make it easy to attack a user from their battles page. The Facebook user selector allows you to enter only those people you are friends with so this will also give us a way to attack people who aren t our friends. We ll add a form to the top of the page that allows the viewer to attack the owner of a battles page. We don t want this form to show up when we view our own battles page. After all we wouldn t want to attack ourselves. We already have the create action working so let s build a form that will reuse it. We can add a hidden field that includes the user s Facebook ID. If we name the field ids we won t have to change our create action. By adding to the end of a form field name you tell Rails that you want the result to be an array. Hiding Content from Users 98 ft Become Part of Facebook When you build a Facebook Platform application you have powerful .