HOME > PLUGINS

HDFPlugin (UNSUPPORTED)

The HDF Web-browser plugin, HDFPlugin, is a "windowed" browser plugin that is launched from a web browser to display HDF4 and HDF5 files. A browser plugin is a software program that extends the power of a web browser by adding more features and supporting more types of content than what the standard browser provides.

The HDF Web-browser plugin is not HDFView. HDFPlugin and HDFView are different software. HDFView is a Java-based standalone application that is used to view and edit HDF4 and HDF5 files and runs on multiple platforms. It has more browsing features and edting features. The HDF Web-browser plugin is a "light" browser that has less browsing features than HDFView. It has no editing features. For more information on HDFView, visit: /hdf-java-html/

The HDF Web-browser plugin is not an Applet. Although both the plug-in and applet are launched in a web browser, there is a major difference between the two. Like other software, a plug-in is downloaded and installed only once. It is installed onto local disk and launched from a local machine. Applets are downloaded at each invocation. Following are the reasons for using a plug-in over an applet:

An HDF applet must have a lot of GUI components, which will make the applet "big". Although applets can be cached, some users clean the cache often for various reasons.
There is no pure Java implementation of the HDF library. A dynamic JNI library is built to bridge the Java and HDF C library. There are different dynamic link libraries for different platforms. It will not work well to use an applet. The applet will not be platform independent because of the dynamic JNI library.

About Current Release

It is a challenge to implement browser plugins. Plugins are platform and browser dependent. Each of these platform/browser combinations has its own requirements. Furthermore, since Microsoft has removed support for Netscape plug-ins from IE 5.5 SP 2 and beyond, plug-ins developed in Netscape Plugin APIs will not work on IE anymore. Netscape/Mozilla does not support ActiveX controls either. It is impossible to implement a single plugin to support all platform/browser combinations.

The current HDFPlugin is a Windows only application. It is implemented as an active document server . An active document server such as Microsoft Office Binder or Internet Explorer hosts documents of other application types called Active documents. An active document is a COM (Component Object Model) component that shows some data (charts, sheets, text documents, bitmaps) which is given by the Active Document Server.

HDFPlugin is an active document server. When you put an HDF file into Internet Explorer, the Internet Explorer (Container) calls HDFPlugin (Server or plugin) to show HDF4 and HDF5 files. The HDFplugin can also run as a standalone application. You can open HDF files directly from HDFPlugin. For more details, read the User's Guide

- - Last modified:April 21st 2008