Client-side programming can download program with Web page, execute on client machine Web Programing a JavaScript ape in 1995 9e for Web pages, developed by a C++/Java-like syntax, so familiar to programmers, good for adding dyramic features to Web page. ontrolling forms and GUI Continuously Changing Information Server Push Technology Needed for Client forms connection Animations Server sends updates repeatedly Rapid updates(e.g, stock pr Achieved with two mechanisms Active document Active Document Technology Active Document Representation a server Desire Sends computer program to client Platform independence Client Efficient execution Runs program locally High-speed data transmission m Program binding Controls display Compact representation .Interpretive execution10 哈工大计算机学院 李全龙 Network Application Development Server Software Design 55 Web Programing 哈工大计算机学院 李全龙 Network Application Development Server Software Design 56 Client-side programming „ JavaScript „ a scripting language for Web pages, developed by Netscape in 1995 „ uses a C++/Java-like syntax, so familiar to programmers, but simpler „ good for adding dynamic features to Web page, controlling forms and GUI „ Java applets ƒ can define small, special-purpose programs in Java called applets ƒ provides full expressive power of Java (but more overhead) ƒ good for more complex tasks or data heavy tasks, such as graphics can download program with Web page, execute on client machine ƒ simple, generic, but insecure 哈工大计算机学院 李全龙 Network Application Development Server Software Design 57 Continuously Changing Information „ Needed for „ Animations „ Rapid updates (e.g., stock prices) „ Achieved with two mechanisms „ Server push „ Active document 哈工大计算机学院 李全龙 Network Application Development Server Software Design 58 Server Push Technology „ Client forms connection „ Server sends updates repeatedly „ Impractical 哈工大计算机学院 李全龙 Network Application Development Server Software Design 59 Active Document Technology „ Server „ Sends computer program to client „ Client „ Runs program locally „ Program „ Controls display „ Interacts with user 哈工大计算机学院 李全龙 Network Application Development Server Software Design 60 Active Document Representation „ Desire „ Platform independence „ Efficient execution „High-speed data transmission „ Late binding „ Consequence „ Compact representation „ Interpretive execution