find a plugin installed?

Question

From web, I want to detect if our application has been installed or not. With number of research, we have found this site:

Detect from browser if specific application is installed

There is a light for us to write something to detect:

if (navigator.plugins["Adobe Acrobat"]) {
// do some stuff if it is installed
} else {
// do some other stuff if its not installed
}

The questions are:

• how the browsers find "adobe acrobat" on the local machine?
• is "adobe acrobat" a plugin installed? how can I check it manually on my machine?
• how to write a program or a plugin like "adobe acrobat" so that I can use: navigtor.plugins?

Thanks in advance.

Answer 1

1 You will have to check each browser vendor for their plugin api.

2a For security, the only way javascript is allowed to check for installed programs is if it is a plugin for that particular browser

2b Each browser is different.

3 Each browser is different. Check the plugin api's (most browsers use a similar api called npapi)