Web – Page 28 – Burningbird

Recovered from the Wayback Machine.

Dynamic HTML Power Guide authored by Shelley Powers, published in January, 1998. 1/19/98 – Finally, at long last, this book is in the bookstores!“Dynamic HTML” book provides over 100 examples covering both Microsoft Internet Explorer 4.0 and Netscape Navigator 4.0 Dynamic HTML. This includes an explanation and demonstration of the style specification standard CSS1, and provides an overview of both VBScript and JavaScript 1.2, to assist in understanding examples written with both scripting languages. The book also has separate sections providing comprehensive coverage and demonstrations of the IE 4.0 and Navigator 4.0 scripting object models.

The end of the book features a section containing complex cross-browser examples such as an online presentation, magazine, game, and catalog page.

What cross-browser techniques will you learn? How to layer content, use layers and DIV blocks together, hide and show content, two different techniques for drag and drop, event capturing, clipping, element movement, and yes, even how to replace content in a page AFTER the page has been loaded. This is in addition to how to maintain DHTML “state”, and how to create cross-browser scripting objects that take care of browser differences.

The book also has fun with each individual browser. Using forms and layers together. Hiding and showing form “hints”. Learn how to emulate the IE shadow and alpha visual filters in Navigator. Play with drag and drop art. Have some fun with Microsoft’s visual and transition filters. Hide and show content, or change the style attribute for content.

The book has been tested against the delivered IE 4.0 product, and Navigator 4.4, on Windows95 and NT.

Book is for an intermediate/advanced audience.

Dynamic Web Publishing Unleashed co-authored by Shelley Powers, published in December, 1997 by SAMS.Book is an overview of Web-based technologies including HTML 4.0, DHTML, CSS1, Scripting, Java 1.1, Channels, server-side techniques and more. If you are new to Web, or have only worked with one or two Web technologies this book can help you “catch up” with the seemingly endless components of Web development. The book follows more of a reference format, meaning that each section can be read in any order. The book also follows the philosophy of “less talk, more code”.

The Channels and VRML chapters, and my commentary chapter on the future of the Web technologies, are online at SAMS at http://www.mcp.com/sites/1-57521/1-57521-363-x/.

Note that there is some confusion at various online bookstores about the size of the book. It is a little over 800 pages in length, not including the online chapters. Also note that this book is not by the same author as Web Publishing Unleashed, follows a different format, and contains new content.

Perl from the Ground Up, by Osborne McGraw-Hill, due to be published in 1997.I wrote the chapters on Object-Oriented Perl, and Perl and the Internet-based libraries. The book promises to be a good overall discussion of Perl that does not require any previous Perl experience.

Java Unleashed 1.1 – published by SAMS, 1997.I wrote the chapters on the SQL classes, and Java Databases. This book provides a good, overall, coverage of the JDK 1.1, including coverage of RMI, JDBC, threads, JAR, networking, sockets, applets, and much more.

Maximum Java 1.1 – published by SAMS, 1997.I wrote the chapters on Managing Media, Finding and Using Resources, and the Java Commerce API. This is a book that covers advanced Java topics such as the Java and VRML 2.0, Reflection and Introspection, factory objects, serialization and persistence and other. This book takes off from where others end.

PowerBuilder 5 How To, co-authored by Shelley Powers, published in 1996 by Waite Group Press.Book is fairly large and answers some of the most common PB 5.0 questions, using the Waite Group Press “Question and Answer” format popular with the “How To” series. In addition, this was the first book on the shelves that provided examples for using the DataWindow plug-ins.

I am particularly proud of the section I wrote on creating the different types of applications, demonstrating that PB applications do not need to be MDI (multiple document interface) apps, only.

Using Perl 5 for Web Programming, co-authored by Shelley Powers, published by Que, 1996.This is an Amazon Bookstore bestseller. I particularly like the company newsletter example I created for this book.

Any information system group that has a client base that is split geographically will have a problem with distribution: how do you notify the clients that a new version of the tool(s) they are using is out, what the version contains, and how to upgrade.

You can automate the upgrade process by using tools that determine that the application a person is accessing is now out of date and upgrading it accordingly. The problem with this approach is that the user will not have control of when the upgrade is occurring and may be wary of an update that they know nothing about.

You can take a more passive approach by sending an email or memo out to all of your clients that an update has occurred to the application and they then can access the update on a certain sub-directory. The problem with this is that unless the update is fixing a problem that the client specifically wants or asked for, they may not be as willing to take the time to make the upgrade to their own installation, and then you in the IS department are now faced with trying to support multiple installations using multiple versions of your product. Additionally, the application user will then have to find this upgrade, download it on their own, and install the upgrade, a multiple step process which can generate problems.

Is there a simple solution? There is a simple possibility.

Many companies are interested in porting applications to the Web in some form of an internal intranet just for this problem. Unfortunately as many IS departments are finding out, most applications will not port to the web that easily. However, this is not the only way the web can be used to solve migration and upgrade problems.

Another approach is to use techniques such as Server Side Includes and to use the concept of the personalized user page. This is a web document that the user will open every morning. The contents of the document have been personalized for the user and presents information from categories that they have chosen. A case in point is that a person who works with Group A in Department 1B for Division J for Company XYZ. They will have a web page that contains new information pertinent to Company XYZ at the top, then information pertinent only to Division J next, information for Department 1B next, and finally information for Group A.

A Server Side Include (SSI) embeds a command line in the HTML document given an extension which is usually .shtml or .stm (the webmaster can determine what this extension is). This type of extension tells the web server to parse the web document for SSI commands before sending the document to the browser. An example of one of these commands is:

<!–#include file=”company.html” –>

This SSI command will instruct the web server to open the file called company.html and load the contents of company.html at this point.

The advantage of this approach should be fairly obvious: the information is specific to the interests and needs of the individual and is presented in such a way that they can examine it for the entire day if they need to; the information can include links to other documents if the person wishes to pursue more in-depth knowledge; and the document can be saved using most browers SaveAs capability. In stead of a flurry of emails which may or may not contain information that is relevant and that can be ignored and difficult to follow or read you have one document that contains all the information.

Another advantage is that no programming is required, and the information for each department can be maintained by each department. Group A maintains the HTML document that is specific to them. If there is no new information a blank HTML document or one containing the words “No New Information” can be given. Division J can maintain their own HTML document, and so on. With the many many simple to use HTML tools this should not be a solution that requires programming intervention.

While presenting a unified approach to information presentation, each group maintains autonomous control over what information is presented.

For our distribution problem, if IS has upgraded software that is in use throughout Division J, a notice can go into the Division J section that a new version of the software is being created, what bugs it will fix and features it will add. When the software is ready, a link can be inserted into the document that will allow the person to download the upgrade with one click of the button. The user can then double click on this file as soon as it is on their machine and the upgrade process can occur.

What is the advantage of this technique over others? The information about the upgrade is presented in the same format and in the same context as the upgrade itself. Information about the upgrade and the upgrade itself are only given to those who are impacted by it.

How can this solve the multiple version problem? After all the user can continue to ignore the upgrade notice and continue on their merry way. Well, this is where the concept of something called a Netscape Cookie comes in.

A Netscape cookie, implemented by both Netscape and Internet Explorer browsers, is a tiny bit of information that is stored locally on the client’s machine and that can be accessed by the browser when a specific web document is loaded. When the document containing the information about the upgrade is loaded, this value is set for the first time. After that point every time the person accesses their personalized web page the cookie is accessed and the value is incremented or decremented. Information can be printed out to the effect that they have so many days to make the upgrade, and this value is decremented for each day.

If they make the upgrade, the cookie information is destroyed and the reader will no longer get the count down.

With additional sophistication, one can create the page in such a way that the download no longer shows once they make the upgrade. To use this approach, persisten information about what HTML documents one specific person will see is kept in a file on the server. When the person logs in and gives their user name and password this file is accessed. Instead of an HTML document the person accesses a file that is called index.cgi. This application will access the file containing the person’s preferences and the information is then used to determine how to build the page the person will see. The application does this by opening up the individual HTML documents that make up the person’s preferences and printing them back to the browser, in turn.

With this approach, after a person makes an upgrade their personal preference file is accessed and the entry that contains the upgrade information is removed. Not only will the person receive timely information that is pertinent to their needs, they will receive content that is dynamic and also matches their choices.

Finally, if the person still does not upgrade by a specific date an email can be generated automatically that will be sent to the IS department informing them of this information.

A link file containing sample Perl script that demonstrates the CGI based approach and that demonstrates the use of SSI can be found here.