1. HDF and HDF-EOS Workshop VIII, October 26-28, 2004 1/12 Peter Cao, National Center for Supercomputing Applications This work is supported in part by a Cooperative Agreement with the National Aeronautics and Space Agency (NASA) and National Center for Supercomputing Applications (NCSA) HDF Web-Browser Plug-in

2. HDF and HDF-EOS Workshop VIII, October 26-28, 2004 2/12 Outline Plug-in Basics Plug-in Basics Development issues Development issues An example: windows plug-in for IE5 An example: windows plug-in for IE5

3. HDF and HDF-EOS Workshop VIII, October 26-28, 2004 3/12 What Is HDFView A browser plug-in is a software program that extends the power of Web browser by adding more features and supporting more types of content than what the standard browser provides A browser plug-in is a software program that extends the power of Web browser by adding more features and supporting more types of content than what the standard browser provides An HDF browser Plug-in is a windowed Plug-in that is launched from Web browser to display HDF4 and HDF5 files An HDF browser Plug-in is a windowed Plug-in that is launched from Web browser to display HDF4 and HDF5 files Web Browser Plug-ins New Datatype New Feature

4. HDF and HDF-EOS Workshop VIII, October 26-28, 2004 4/12 Reasons for a HDF Plug-in Click-and-view : by clicking on or drag-drop a HDF file, the browser will recognize and display the file (much like the acrobat reader plug-in for pdf files) Click-and-view : by clicking on or drag-drop a HDF file, the browser will recognize and display the file (much like the acrobat reader plug-in for pdf files) Easy install and update : downloading and installing the plug-in is just a simple click. No uninstall and reinstall is necessary for new release. Users will be asked for automatic update when a new version is released Easy install and update : downloading and installing the plug-in is just a simple click. No uninstall and reinstall is necessary for new release. Users will be asked for automatic update when a new version is released Browse remote files : with predefined the MIME type, the plug-in will take the advantage of the web browser to browse HDF files over the internet Browse remote files : with predefined the MIME type, the plug-in will take the advantage of the web browser to browse HDF files over the internet

5. HDF and HDF-EOS Workshop VIII, October 26-28, 2004 5/12 How Plug-ins Works Web Browser: Internet Explorer Netscape Mozilla Browser Side Plug-in API Plug-in Java C C++ Plug-in Side Plug-in API HDFLibrary HDF File A standard set of plug-in APIs are defined for communication between applications and the browser Netscape Plug-in APIs Netscape Plug-in APIs Microsoft ActiveX controls Microsoft ActiveX controls

6. HDF and HDF-EOS Workshop VIII, October 26-28, 2004 6/12 Implementation Challenge Plug-ins are platform and browser dependent Platforms Platforms Windows Windows Mac Mac Linux Linux Solaris Solaris Browsers Browsers Internet Explorer Internet Explorer Netscape or Mozilla Netscape or Mozilla

7. HDF and HDF-EOS Workshop VIII, October 26-28, 2004 7/12 Implementation Challenge continue Since Microsoft has removed support for Netscape plug-ins from IE 5.5 SP 2 and beyond, plug-ins developed in Netscape Plug-in APIs will not work on IE. Netscape/Mozilla does not support ActiveX controls NS Plug-in APIs Microsoft ActiveX IE 5.5 SP 2 + Netscape/Mozilla

8. HDF and HDF-EOS Workshop VIII, October 26-28, 2004 8/12 Choice: Microsoft ActiveX Pros: Better performance (speed and memory) Better performance (speed and memory) Easy installation (one piece software) Easy installation (one piece software) Works best for IE, which has 80% of the users Works best for IE, which has 80% of the usersCons: Works only on IE and Windows. Works only on IE and Windows. Maintenance and support Maintenance and support

9. HDF and HDF-EOS Workshop VIII, October 26-28, 2004 9/12 Choice: Java Pluglet API A Pluglet is a Plug-in that is written in Java and a close Plug-in 1:1 implementation of the C++ Plug-in API in Mozilla Plug-in API Plug-in API Pluglet Pluglet Engine (Java) JVM (C++) Plug-in API (NS API) IEMozilla ActiveX

10. HDF and HDF-EOS Workshop VIII, October 26-28, 2004 10/12 Choice: Java Pluglet API continue Pros: Support all major platforms Support all major platforms Easy maintenance (reuse HDFView code) Easy maintenance (reuse HDFView code)Cons: Lower performance (Java  C) Lower performance (Java  C) Requires Java Runtime Environment Requires Java Runtime Environment Installation (classpath, JNI path, security) Installation (classpath, JNI path, security)

11. HDF and HDF-EOS Workshop VIII, October 26-28, 2004 11/12 Short Demo: Plug-in For IE

12. HDF and HDF-EOS Workshop VIII, October 26-28, 2004 12/12 Questions