iframes trên trang vải, nhưng bạn không thể sử dụng cùng một khung nội tuyến vào các mã trong hộp hồ sơ. Ngoài ra còn có một danh sách các thẻ yêu cầu đang được xem xét để đưa lần lặp kế tiếp thiết lập tag FBML. Mặc dù không phải tất cả các thẻ sẽ được đưa vào ngôn ngữ chính thức, | 48 Learning Facebook Platform Fundamentals iframes on canvas pages but you cannot use the same iframe on the code in the profile box. There is also a queue of requested tags that are being considered for inclusion with the next FBML tag set iteration. Although not all of these tags will make it into the official language it s interesting to see what the developer community is requesting to be included. You can view and add to these requests at http Requested_FBML_Tags. The developer s wiki for the Facebook platform groups the tags by their function. I believe this is perhaps the most useful way to work with the FBML because of the sheer volume of tags almost 100 as of version . Also because of this volume some tags will necessarily have more information about them than others. If you find some of these descriptions and examples insufficient please refer to the official documentation for the tags. FBML tags are set apart from other HTML tags with the fb prefix and follow the format fb tag_name . Conditionals FBML contains many conditional tests that can help you cut down on implementing this code in your application. At the heart of these conditionals is the fb if tag fb if value true p Hi p fb if At first glance this isn t that useful because the value attribute will always be true. This is where your programming language comes into play. To actually make this do something useful you need to be able to dynamically set this value. Let s write a short test to see whether the logged-in user has a user ID of 12345 and show a customized message php user facebook- require_login test false you may also use 1 0 for true false if user 0000001 test 1 fb if value php echo test p This is the secret message. p fb else Graham Learning Facebook Platform Fundamentals 49 p No secret message for you p fb if This is a nonsense example but it shows how you can you use the fb if fb else construct to display custom messages to your users. You .
