Browsinform Technical Description

Technical Description		How it Works Requirements Performance On-line Doc & Samples Sun JDK installation Usage Tips Revision history

This page gives a brief technical overview of Browsinform. If you have any additional questions or comments, please review the Overview, or email browsinform@mandosoft.com.

How it Works

When the query HTML page is displayed, it invokes the iDB applet. That applet reads the data file for each application, parses it and stores it in the browser's cache.

All further operations (queries, sorts, drill-downs, details display) occur within the browser, i.e., the original file is not accessed again.

While reading the data file the applet also starts processing that file making the first query operate faster.

Security: as such, Browsinform does not promote or prevent security precautions. The datafile is only shown in a read-only mode. You may elect to write-protect that file, or restrict its read-access without impacting your Browsinform applications, provided the file is still accessible by the browser; the particular restrictions and possibilities depend on your operating system and web server.

You can also encrypt and password-protect your data files to make sure that only authorized users can view the data.

Because of the way Java applets work within the browser, the browser may keep a copy of the datafile in its cache. The data in that cache cannot be protected, i.e. the data could be read from the cache after the applet has been unloaded or the browser window closed.

Browsinform does not read (except for the datafiles) or write any files on your computer, and is therefore unable to access or transmit any private information.

Browsinform can also dynamically connect to a Web Server, which allows you to query a live database in real time. No special software is required on the browser's end, or on the server (except of course the actual backend program support, e.g., a Web Server and PERL). You can use any backend support you wish (e.g. PERL / Java, CGI, ASP, ColdFusion, Servlets, etc.).

Platform / Browser Requirements

Because Browsinform uses only standard Java (1.1), HTML (3.2) and JavaScript (1.1), it can be used in any browser (e.g., Netscape, Microsoft Internet Explorer) or platform (Windows, Unix, Mac), provided that:

The browser must support Java 1.1 or above and JavaScript 1.1 and above (Netscape version 4 and above, MSIE version 4 and above)
The browser's Java and Javascript support must be enabled in the user preferrences
The CSV datafile can be generated by any standard application (e.g., MS Excel or Access, Corel's Quattro Pro), or even using a standard text editor. Both Unix and Windows line and file endings are supported.

We try our best ensure that Browsinform is compatible for all platforms and browsers as described above. However, there is always a possibility that a configuration we haven't yet encountered poses problems. If that is the case, please contact us.

We will adapt or upgrade the Browsinform code as needed, as new platforms or browser features are released by their manufacturers.

Performance Limitation

The Browsinform application operates within the browser and is therefore subject to the limitations of the browser itself. The main performance concern is with the datafile size. The maximum file size that Browsinform can process depends on:

the number of rows in the file
the number of columns in the file
the length of the text in each of the columns
the amount of physical and virtual memory on the computer
the amount of memory dedicated to the browser's cache
the efficiency of the Operating System's memory management (e.g., Unix seems generally much more effective than Windows)
the type and version of the browser you are using
the other applications and system resources currently loaded or running on your PC

For example, we have found that on a standard-equipped Windows 95 PC, while Microsoft Internet Explorer has no problem processing files over 1.5 Mb, Netscape has trouble with files larger than 1 Mb. Of course, as stated above, these values depend on the particular machine and configuration your are using. Note that each browser and Operating System deals with lack of memory or memory overload in a different fashion and may or may not lock up your PC when experiencing problems.

In practice, the files you will be using will probably be far below the limit: for example a typical datafile of 1000 records may be 200Kb or less, depending on the amount of data you store.
If you are dealing with very large amount of data, a server-based solution may be more appropriate than Browsinform anyway.

Note also that the combinations of the above factors, plus the processor speed and cache, may affect the search and display speed as well.