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-inHDF Web-Browser Plug-in

HDF and HDF-EOS Workshop VIII, October 26-28, 2004 2/12

OutlineOutline

Plug-in BasicsPlug-in Basics Development issuesDevelopment issues An example: windows plug-in for IE5An example: windows plug-in for IE5

HDF and HDF-EOS Workshop VIII, October 26-28, 2004 3/12

What Is HDFViewWhat Is HDFView A A browser plug-inbrowser plug-in is a software program that extends is a software program that extends

the power of Web browser by adding more features the power of Web browser by adding more features and supporting more types of content than what the and supporting more types of content than what the standard browser providesstandard browser provides

An An HDF browser Plug-inHDF browser Plug-in is a windowed Plug-in that is is a windowed Plug-in that is launched from Web browser to display HDF4 and launched from Web browser to display HDF4 and HDF5 filesHDF5 files

Web Browser

Plug-ins

New Datatype

New Feature

HDF and HDF-EOS Workshop VIII, October 26-28, 2004 4/12

Reasons for a HDF Plug-in Reasons for a HDF Plug-in Click-and-viewClick-and-view:: by clicking on or drag-drop a HDF file, by clicking on or drag-drop a HDF file,

the browser will recognize and display the file (much like the the browser will recognize and display the file (much like the acrobat reader plug-in for pdf files)acrobat reader plug-in for pdf files)

Easy install and updateEasy install and update: : downloading and installing downloading and installing the plug-in is just a simple click. No uninstall and reinstall is the plug-in is just a simple click. No uninstall and reinstall is necessary for new release. Users will be asked for automatic necessary for new release. Users will be asked for automatic update when a new version is releasedupdate when a new version is released

Browse remote filesBrowse remote files:: with predefined the MIME type, with predefined the MIME type, the plug-in will take the advantage of the web browser to the plug-in will take the advantage of the web browser to browse HDF files over the internetbrowse HDF files over the internet

HDF and HDF-EOS Workshop VIII, October 26-28, 2004 5/12

How Plug-ins Works How Plug-ins Works

Web Browser:Web Browser:Internet ExplorerNetscape Mozilla

Browser Side Plug-in API

Plug-inPlug-inJavaCC++

Plug-in SidePlug-in API

HDFHDFLibraryLibrary

HDF File

A standard set of plug-in APIs are defined for A standard set of plug-in APIs are defined for communication between applications and the browser communication between applications and the browser

Netscape Plug-in APIsNetscape Plug-in APIs Microsoft ActiveX controlsMicrosoft ActiveX controls

HDF and HDF-EOS Workshop VIII, October 26-28, 2004 6/12

Implementation ChallengeImplementation Challenge

Plug-ins are platform and browser dependentPlug-ins are platform and browser dependent PlatformsPlatforms

WindowsWindows MacMac LinuxLinux SolarisSolaris

BrowsersBrowsers Internet ExplorerInternet Explorer Netscape or MozillaNetscape or Mozilla

HDF and HDF-EOS Workshop VIII, October 26-28, 2004 7/12

Implementation Challenge Implementation Challenge continuecontinue

Since Microsoft has removed support for Netscape plug-ins Since Microsoft has removed support for Netscape plug-ins from IE 5.5 SP 2 and beyond, plug-ins developed in Netscape 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 Plug-in APIs will not work on IE. Netscape/Mozilla does not support ActiveX controlssupport ActiveX controls

NS Plug-in APIsNS Plug-in APIs Microsoft ActiveXMicrosoft ActiveX

IE 5.5 SP 2 +IE 5.5 SP 2 +Netscape/MozillaNetscape/Mozilla

HDF and HDF-EOS Workshop VIII, October 26-28, 2004 8/12

Choice: Microsoft ActiveXChoice: Microsoft ActiveX

Pros: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 usersWorks best for IE, which has 80% of the users

Cons:Cons: Works only on IE and Windows. Works only on IE and Windows. Maintenance and supportMaintenance and support

HDF and HDF-EOS Workshop VIII, October 26-28, 2004 9/12

Choice: Java Pluglet APIChoice: Java Pluglet APIA A PlugletPluglet is a is a Plug-in that is written in Java and a close that is written in Java and a close 1:1 implementation of the C++ 1:1 implementation of the C++ Plug-in API in Mozillain Mozilla

PlugletPluglet

Pluglet EnginePluglet Engine(Java)(Java)

JVMJVM

Pluglet EnginePluglet Engine(C++)(C++)

Plug-in APIPlug-in API(NS API)(NS API)

IEIEMozillaMozilla

ActiveXActiveX

HDF and HDF-EOS Workshop VIII, October 26-28, 2004 10/12

Choice: Java Pluglet API Choice: Java Pluglet API continuecontinue

Pros:Pros: Support all major platforms Support all major platforms Easy maintenance (reuse HDFView code)Easy maintenance (reuse HDFView code)

Cons:Cons: Lower performance (Java Lower performance (Java C) C) Requires Java Runtime EnvironmentRequires Java Runtime Environment InstallationInstallation (classpath, JNI path, security) (classpath, JNI path, security)

HDF and HDF-EOS Workshop VIII, October 26-28, 2004 11/12

Short Demo: Plug-in For IEShort Demo: Plug-in For IE

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

QuestionsQuestions