Static vs. Dynamic Content

This document provides an overview of the differences between static and dynamic content, how ExSite manages these, and various tricks you can use to mix and match them.

Static Content

Static content is published to regular files on your server and handled using the simplest methods available to the web server. The advantages of static content are:

it is the fastest and most efficient way to deliver content
it does not require any code to execute or any databases to be accessed, which makes it the most secure way to deliver content
it uses simple, clean URLs to address the content
it takes best advantage of web caching systems, which further boosts performance
it is compatible with every type of webserver technology

However, it also has the following disadvantages:

it must be republished when it changes, or your viewers will not see the updates
it cannot display differently to different viewers, depending on their login status or other factors

Dynamic Content

Dynamic content is generated for you at the time you request the page. The document you view exists only for you at that moment; if viewed by someone else at the same time, or by you at a slightly different time, you could get something different. Dynamic content is good for:

pages whose content changes too quickly to easily republish it
pages that display viewer-specific content (eg. user profiles)
pages that display content conditionally (ie. member-only pages)

However, dynamic content has the following disadvantages:

it is resource-intensive compared to static pages. That means the number of dynamic pages your server can display per second will generally be much less than the number of static pages. This can be especially important if you are swamped with traffic, or generating thousands of dynamic page views for robots or other automated agents that you don't really care about.
dynamic pages execute code on your server, and can read from and write to your database. If your website has any security problems, dynamic pages is where those problems will be exposed.
in many typical default webserving configurations, the index page of a website is presumed to be a static page (eg. "index.html"). That means there are some places where it is impractical or more difficult to use dynamic pages than others.

Default View

Every page can declare whether it is static or dynamic. This determines the default view of the page, for example the initial view of the page when you first navigate to it from a menu.

Static is the most efficient method, but some pages are best set to a dynamic view, because their contents change rapidly or unpredictably. For example, forums can be updated at any time by readers, so a dynamic view works best to display the current comments.

Private (member-only) pages are dynamic by default, because they display different content depending on who is viewing them.

Switching from static to dynamic

Pages in ExSite are not either static or dynamic, but can switch between these modes as needed. The static URL to a page will be something like:

http://foobar.com/somepage.html

whereas the dynamic URL will be something like:

http://foobar.com/cgi/page.cgi?_id=123

http://foobar.com/cgi/page.cgi/somepage.html

If available, the static representation is used as the default page view because it is more efficient, but it will automatically switch to dynamic if necessary.

Pseudo-Dynamic Pages

There are a few tricks for getting some of the benefits of a dynamic page, while using a published static HTML file that is served like a static page.

DHTML (client-side dynamic content)

This method requires that you use Javascript to modify your content, allowing for a small amount of flexibility in varying what you display to your viewer. One example in ExSite is the Login plug-in, which detects whether you are logged in or not, and displays either a login or logout link. This allows normal static pages to adjust their displayed functions depending on the viewer, without actually executing any server code or connecting to your database.

Scheduled republishing

This method uses automatic republishing tools to regenerate a static page at regular intervals. That allows the static page to be updated with current content, without the webmaster having to log in and manually republish every time something new happens. This method is good for general content that changes frequently, but will not work for user-specific content that changes for each viewer.

Check out the article on ((Scehduled Publishing)) for more information.

AJAX

This method uses AJAX to dynamically fetch certain page elements and insert them into a published static page. For example, a static home page could include an AJAX-generated index of the most recent user comments from the forums. Such pages are partially static and partially dynamic. Robots will generally ignore the AJAX calls, and get only a static page.

ExSite allows you to automatically run any plug-in in AJAX mode, with a minor change to the plug-in tag. See the article on ((Working with Plug-ins)) for more information on using AJAX.

Pseudo-Static Pages

Similarly, there are some tricks you can use to make it appear that a page is static, when in fact it is fully dynamic:

Clean URLs

with this method, the page indexing information is passed as path data rather than query data in the URL. A dynamic page URL like

http://foobar.com/cgi/page.cgi?_id=123

will become something like:

http://foobar.com/cgi/page.cgi/somepage.html

This resembles the style of URL used for static pages, and may get you some of the caching or SEO benefits reserved for static pages. A sharp eye will still spot the "/cgi/page.cgi" part of the address, and recognize that as characteristic of dynamic pages. You can use Apache's mod_rewrite tools to edit this out of the URLs, if that concerns you.

Note that clean URLs are slightly more costly to use, because they require more database lookups to find the page than the default URL style.

To get clean URLs for your basic pages, use the following configuration setting in your exsite.conf file:

page.dyn_url_type = path

Some plug-ins can also support clean URLs. You may need to add additional configurations to extend clean URLs into these plugins. For example, to also get clean URLs on your e-Zines and articles, add the following configuration parameter to your Zine.conf file:

link_style = path

Prepublishing Dynamic Pages

With this method, all pages are published to disk, whether static or dynamic. However, for the dynamic pages, the dynamic elements of the page (namely the plug-ins) are left unresolved. In the published page's HTML file, they appear as CMS tags. If the page is viewed as a normal static file, those tags are treated as HTML comments and they do nothing - the plug-in area will appear blank. If, however, the page is viewed using the clean URL method (above), ie.

http://foobar.com/cgi/page.cgi/somepage.html

then ExSite will display the published HTML file, and dynamically expand the remaining plug-ins on the page. Mod_rewrite can be used to translate the "static" URL http://foobar.com/somepage.html to the dynamic URL noted above.

If any of the pages are truly static, they will still display correctly if they are translated to the dynamic URL. That means it is quite safe to rewrite all URLs to the dynamic form.

To prepublish your dynamic pages, set the following configuration setting in your exsite.conf file:

page.prepublish_dynamic = 1

To have ExSite always link to the static URL for these dynamic pages, you should also set:

page.static_urls = 1

but if you do this you will need to add some Apache mod_rewrite instructions to run all static page URLs though page.cgi, for example:

http:://www.foo.com/page.html -> rewrite to http:://www.foo.com/cgi/page.cgi/page.html

Redirecting to Dynamic Pages

This method publishes a dummy static page that consists of nothing more than a meta-refresh instruction that redirects the browser to the actual dynamic page. Links and menus will point to the dummy static page.

The effect for regular visitors is that they see the URL of the static dummy page in their address bar, but they receive the content of the full dynamic page. Robots will crawl the efficient dummy static page, rather than tax your server with requests for dynamic pages. (Smart robots will see the meta-refresh instruction and come back later for the dynamic page, but dumb robots may just leave it at that and stop pestering your website.)

To publish dynamic pages to a meta-refresh instruction, add the following configuration setting to your exsite.conf file:

page.redirect_dynamic = 1

Relative URLs

ExSite can use full or relative URLs, and the choice can be different on static and dynamic pages. The default configuration settings are:

page.relative_static_url = 0

page.relative_dynamic_url = 1

Dynamic Content Objects

We have been discussing page views above, but it is also possible to view particular images or files (non-HTML pages) either dynamically or statically. If a content object is published to disk, it will have a normal URL such as:

http://foobar.com/_Library/docs/somefile.pdf

(The specifics of the URL will vary depending on whether the file is placed in a library, template, or normal page.)

The same content object can also be viewed dynamically, eg:

http://foobar.com/content.cgi/somefile.pdf?id=789

The advantage of dynamic content views is that they can be restricted to certain users (eg. members-only documents).