Plugin for Netscape Navigator

Last Updated: January 23, 1997
For Netscape Navigator versions 2.02 and 3.0

Overview

The Microsoft Win32 Virtual Machine for Java (Microsoft VM) plugin allows users of Netscape Navigator to use Microsoft's implementation of the Java VM for Win32. Once the plugin dynamic link library (DLL) and the Microsoft VM are installed on a user's machine, the <embed> tag can be used to cause Java programs running inside Navigator to be executed using Microsoft's VM.

Installation

To install the plugin for Navigator, place npmsjava.dll in the .\program\plugins subdirectory of the Navigator installation tree (which is usually c:\program files\netscape\navigator). The location can be discovered programatically by querying the registry for the navigator installation directory.

HTML Syntax

To use the plugin inside of Netscape Navigator, you must use the <embed> tag. Here is a list of the <embed> tag attributes you will need to do this.

Attribute Description

src The Java class file.

code The Java class file.

codebase | basehref Location of the Java class file.

type Type of object to create. Value="application/java | application/ms-java"

width Pixel coordinates for the width of the applet.

height Pixel coordinates of the applet height.

param Specifies the parameters for the applet. When the param keyword is found, it must be followed by the name= and value= attributes.

param_name Parameter name for the applet. Must be followed by param_value.

param_value Value of a parameter for the applet.

Attribute	Description
src	The Java class file.
code	The Java class file.
codebase \| basehref	Location of the Java class file.
type	Type of object to create. Value="application/java \| application/ms-java"
width	Pixel coordinates for the width of the applet.
height	Pixel coordinates of the applet height.
param	Specifies the parameters for the applet. When the param keyword is found, it must be followed by the name= and value= attributes.
param_name	Parameter name for the applet. Must be followed by param_value.
param_value	Value of a parameter for the applet.

Specifying Parameters

The plugin for Navigator allows a content developer to specify parameters in one of the following three ways:

<embed src="foo.class" myparam=foo>
<embed src="foo.class" param name="myparam" value="foo">
<embed src="foo.class" param_name="myparam" param_value="foo">

The first method is to simply describe your parameters in the embed syntax. The second method is to use the param keyword followed by name= and value=. The third method is to use the param_namekeyword followed by the param_value keyword.

Differences Between Navigator 2.02 and Navigator 3.0

Navigator 2.02 does not support the type attribute.
Navigator 2.02 does not support the creation of multiple objects with the same src attribute.

You can easily get around the limitations of Navigator 2.02 by creating a dummy class file that contains at least one byte.

In the above example, foo.class and bar.class are dummy files on the server (that contain at least one byte).

Examples

Navigator 3.0 - Using the SRC Attribute
<embed src="my.class" width=100 height=100 myparam=foo myotherparam=bar>

Navigator 3.0 - Using the TYPE Attribute
<embed type="appication/java" code="my.class" width=100 height=100 myparam="foo" myparam2="bar">

Navigator 3.0 - Two Applets Using the Same Class
<embed src="my.class" width=100 height=100 myparam=foo myotherparam=bar>
<embed src="my.class" width=100 height=100 myparam=baz myotherparam=zed>

Navigator 2.02 - Two Applets Using the Same Class
<embed src="dummy1.class" code="my.class" width=100 height=100 myparam=foo myotherparam=bar>
<embed src="dummy2.class" code="my.class" width=100 height=100 myparam=baz myotherparam=zed>

System Requirements

The plugin requires Microsoft's VM for Java, which is shipped as a component both of Microsoft Internet Explorer 3.01 and of Microsoft's SDK for Java.

Compatibility

The plugin for Navigator is compatible with Netscape 3.0 and Netscape 2.02.

Known Issues

When this plugin is used with Netscape Navigator 2.02, some drawing and repainting problems have been reported. This is not a defect in the plugin, but rather is caused by the fact that Navigator 2.02 does not always instruct child windows to repaint when necessary. The Navigator release notes advise reloading or resizing the page to force a repaint in these cases. However, this is not a feasible option for a Java VM plugin.

The Microsoft VM for Java plugin utilize's its own network DLLs and cache. There is a known problem when navigating to a file URL and then an HTTP URL. There is a collision between the version of WinSock utilized by the plugin and the WinSock utilized by Netscape. To avoid this problem, always navigate to an URL first.