FireFox Extension Development Question

[Andy]

What I want to do is code a FireFox plugin / extension to display intraday charts of stock prices extracted from a Dynamically Updating Java Applet (one that is already running on a web page). Is this possible?

Sure it may be difficult to do, but I just need to know if it is possible at the moment since I don't know much about how Java works. What I don't want to do is continually poll a URL.

Firefox extensions seem to use Javascript to modify the page or new window, so I guess I will use Javascript to inspect the DOM of the web page at regular intervals with a timer or implement a listener function on incoming internet data.

Very early days so far, I only worked through a tutorial of how to make a "hello world" plugin so far.

So if you have any tips on how to go about doing this, please comment 

[Manu]

You might find this interesting - http://www.madan.org/tickertool/

It really depends. First you should decide where will you display the charts. If you want to display indices, you much decide which one. It should be possible as there are hundreds if not thousands of windows vista sidebar widgets which yields just the same. Secondly, if individual stock's chart, then how do a user search for the same etc. etc.

The professional traders I know use their sophisticated software. The less frequent Internet savvy traders that I know mostly use Google finance or their fav. websites to track and see intraday charts. They use firefox search engine plugin for their fav. tool.

[Andy]

Thanks for the suggestions but I want to code my own so I can access and process the data stream with code.

An example of an existing solution: http://www.sharescope.co.uk/sharescript.php

[Andy]

It seems like it may not be possible to grab the text from a Java Applet since it is not part of the visible code or in the DOM.

So it may require sniffing the HTTP stream of data delivered to the browser from the server. Then I would expect the data to be encrypted in some way. Oh dear! Also, I had the idea to hack the JAVA runtime code if it is open source and recompile my own version that outputs text to another application, that would be the ideal way to do it I think.

Also a super computer could be used to perform OCR (Optical Character Recognition) on rapidly changing and scrolling images showing text to do what I wanted.

Grabbing delayed stock price results is probably easier since I used to download text files of 15 minute delayed prices in a list format from a particular site. But 15 minutes is a long time when you are day trading.

I may have to give up on this idea, but at least I got some idea about how you create a FireFox extension/plugin.

Update: it's possible by finding the data in memory. But the data may change location with each new instance maybe? So your code could scan the computer memory for a pattern that signals the start of the data that you are looking for. But this would be not be possible in a FF extension.