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Building Servlets.com, Part 1: Dreamweaver 4 Templates
May 15, 2001

by Jason Hunter

In this article, the first in a series, I'll show how Dreamweaver 4 templates have aided me in building Servlets.com, and I'll share some tips and tricks from my experience to help you make the most of templates.

For about nine months last year this web site ran into a serious state of disrepair. Pages weren't being updated, content wasn't being added, and this soapbox stayed silent. Not coincidentally, these were the same nine months I was heads-down working on the 2nd Edition of my book Java Servlet Programming. Seems I can write a book or I can publish a website, but I can't do both.

With the recent publication of the 2nd Edition I've had the time to do a full revamp of the site, bringing content up to date and creating a solid foundation for future growth. As part of this site recreation effort I've had some interesting experiences with some new technologies like Tea and RSS, things that weren't available when I first set up the site, and I've decided to write a short series of articles discussing the fun discoveries I've made and continue to make in creating Servlets.com. This article is the first in the series. Here we look at how the new Dreamweaver 4 helps me with the site.

I Want a Common Look

One of the most basic problems in web design is creating a consistent user experience from page to page. On Servlets.com for example, I want a common look to the site with a standard header, footer, and sidebar. I also want to be able to change the standard content (perhaps adding a new sidebar item) easily and have that change propagate readily throughout the site. If possible, I'd like to do this without placing an extra burden on the server at runtime.

There are many solutions to this problem people have tried including:

  • Create a basic prototype HTML file and start with a copy of that prototype file when creating each new file. This is the standard way to go, we've all done it, and we all know the problem: making a change to a template helps new files, but old files remain unchanged and updating them is a painful often manual process.
  • Use a dynamic include mechanism, like a JSP <%@ include %> directive or a server-side include. This tends to work better than above, but there are several limitations: There's now a runtime burden placed on the server to serve dynamically what could and should be served as a simple static file; editing the included content isn't amenable to HTML editors because they're just page fragments; and perhaps most importantly, relative links in the included content are next to impossible to manage because you never know from where the content will be included. Relative links are always good style but they're absolutely essential with the introduction of web applications where content must be pluggable into the server at any URI path.
  • Use a templating technology like XMLC or Cocoon to separate the data from the presentation. This has its merits for dynamic content (as written in the 2nd Edition of my book) but it's serious overkill for serving what really should be static files.

For this update of Servlets.com I've found an off-the-shelf technology that solves my problem perfectly and easily: Macromedia Dreamweaver 4 templates.

Macromedia Dreamweaver 4

The idea behind Dreamweaver 4 templates is simple. First, you create an HTML file using the pretty darn cool Dreamweaver 4 HTML editing tool. Into this file you put your standard content: your header, footer, sidebar, etc. You then mark blocks of the page as editable regions. These are the portions of the page where other pages derived from this template will be free to make customizations. For Servlets.com I use a simple template with editable regions for the title (the text in the blue box), deck (the text under the blue box), and main content. Any time I create a new HTML file I tell Dreamweaver to have it use the template, and I simply fill in that page's title, deck, and main content into the editable regions.

When I change and save the template, Dreamweaver asks if I'd like to update all pages derived from that template. I can do a mass update, or be selective about it. The derived pages are updated and saved and ready to be served as static HTML files. Dreamweaver takes care of "building" the pages offline!

Here are detailed instructions for using templates in Dreamweaver:

To create a new template:

  1. Open a new Dreamweaver window
  2. Create a simple prototype page, with "Content goes here" placeholders
  3. Save the file as a template ("File -> Save as Template...")
  4. Highlight each placeholder content block and mark the block as an editable region ("Modify -> Templates -> New Editable Region")

To create a page using a template:

  1. When creating the file use "File -> New from Template..."

To apply a template to an existing page:

  1. Open the file
  2. Select "Modify -> Templates -> Apply Template to Page..."
  3. Dreamweaver applies the page content to the editable region of your choice

Besides being easy to administer and light on the server, Dreamweaver templates avoid the "relative link problem" that plagues server-side includes. How you ask? By employing a little magic. During the update process all relative URLs are adjusted automatically depending on the page's location in the site. In other words, if your template refers to "../images/banner.png" then a page two levels deeper will have the path adjusted to "../../../images/banner.png".

Templates are generally stored in doc_root/Templates. When writing relative links in a Template you should make sure to use relative links rooted in doc_root/Templates, so for example a reference to doc_root/images/banner.png should be written as ../images/banner.png. If you use the Dreamweaver GUI to drag-and-drop your links you don't have to worry about this.

Another perk I've found while using Dreamweaver is that it has an easy site manager (see the "Site -> New Site..." option) which lets you view your file set as a unit and switch between different sites you're working on easily. What's best about the site manager is that if you use the Site window to move or rename files, Dreamweaver offers to automatically correct all links pointing at the file within your site. Ah, if only Dreamweaver could correct all links on the Internet at large, eh?

How It Really Works

If you look at a template file or file derived from a template, you'll notice Dreamweaver adds HTML comment markers within the files. For example, this is the HTML block that declares the Deck of a Servlets.com page:

<font SIZE="+1" COLOR="#003366"><B>
<!-- #BeginEditable "deck" -->Deck<!-- #EndEditable -->
</B></font>

The default value is "Deck" but any page can override that. There is HTML outside the editable region setting a default font size and color. This lets me change the deck look later quickly and easily.

Because simple HTML comments drive the templating mechanism, Dreamweaver templates work well for editing JSP files, Tea template files, Velocity files, and so on. Since I use Dreamweaver to edit Tea files, I've found it useful to tell Dreamweaver to treat *.tea files as HTML documents so it knows to update them during the template update process. New file types like *.tea are added by manually editing the dreamweaver_root/Configuration/Extensions.txt file. I notice JSP files are recognized by default.

For users of WebMacro, there's an interaction problem between the WebMacro parser and the Dreamweaver comment syntax. When WebMacro's parser (as of 0.95p1) sees #BeginEditable it parses it as a WebMacro directive because that's exactly what WebMacro directives look like. When WebMacro tries to load the directive it fails and errors out. For a trick on how to get things working with WebMacro see the WebMacro list archives Message #5668.

Tips and Tricks

Related Reading:
DreamWeaver 4: The Missing Manual

DreamWeaver 4: The Missing Manual
By Dave McFarland
July 2001 (est.)
0-596-00097-9,
420 pages (est.), $24.95 (est.),
Pre-order with Amazon

There are a couple things I had to learn the hard way while using templates: First, it sometimes happens that you want to force the content within an editable region to update across all pages. For example, you might accidentally have placed a <font> tag within the editable region and later want to move it outside so that the font can be changed sitewide without editing each page. Or you might want to update the standard title for all pages. Dreamweaver templates are designed to change what's outside an editable region, not what's within a region, so the two best ways I've found to do such updates are:

1. Write a little Perl or sed script to manually adjust the content. This has the advantage that existing content in the editable region can be massaged into the new form. This works well for the <font> example given above.

2. Remove the editable region from your template, update all pages, then add back the editable region and update all pages again. This clears out any previous values and starts all pages fresh. This works well for the page title example given above.

Another thing I noticed was that in the template creating a link to "../" to point at the site home page does not work due to a bug in the update logic. Dreamweaver for some reason changes the link to a file: URL as it updates. The easy workaround is to point directly at ../index.html or whatever your front page is.

There are some limitations to the Dreamweaver template mechanism. For example, if you have a front page with a slightly different look than the other pages you might have to manage two template files or edit the front page manually. For Servlets.com I got lucky when I discovered that setting the title and deck regions to the empty string creates HTML that effectively ignores the overall blue box and deck region. On IE there's a thin blue line on the front page, but it actually looks kind of stylish.

If I hadn't been so lucky, I could have used Dreamweaver library components. These components are bits of HTML managed as individual assets that can be included into a page. Any later change to the library component can be pushed to all pages using that library component the same way template changes are pushed to pages using the template. Multiple template files might use the same library component, so with libraries there's a mechanism to change content across templates as well.

Conclusion

Dreamweaver 4 templates have made the revision and management of Servlets.com dramatically easier than before when I used simple static files for all content and sed scripts to manage sitewide updates. I'm not generally the kind of person that relies on tools much beyond vim and javac, but for Dreamweaver 4 I'll make an exception. If you're interested in getting Dreamweaver, it's a commercial product from Macromedia available on Amazon. There's also a book coming out in July 2001 from O'Reilly titled Dreamweaver 4: The Missing Manual.


This is the first in a new series of articles. To be notified when new articles are added to the site, subscribe here.

Care to comment on the article? Fire an email to dreamweaver-talkatservlets.com. Interesting comments may be posted unless you specify otherwise.

 


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