How to make dynamically-generated content searchable in WordPress?

I’m writing a plugin for WordPress that dynamically generates content from a Google Documents Spreadsheet. Specifically, the plugin provides a shortcode that generates a good-looking staff list. It works, but there are two problems:

1. Pages that use the shortcode load a little slow, because they have to make multiple requests to another server
2. Since the content is generated when the page is loaded, the contents of the staff list do not show up in search results on the site

I can fix the first problem with some level of caching, but what can I do about the second problem? I mention the first problem because I think the ideal solution is one in which WordPress indexes the cached copy of the page.

Another solution I can think of would be to have the content of the page composed by a plugin periodically. That way the page could be searched and wouldn’t be dynamically generated every time. However, it seems like a strange paradigm for a plugin to completely control the content of a page…are there other plugins that do this? Also, this approach exposes complexity to the user that it shouldn’t have to. (They’d have to edit the contents of the page from a plugin page instead of the normal place.)

Here’s a sample of what part of the markup for the page looks like:

<h2>General Management</h2>

[staff-directory department="General Management"]

The spreadsheet to hit is configured separately. The “department” specifies the worksheet. (I’d show you what the results look like, but I don’t have enough rep to post an image.)

Your suggestions are greatly appreciated.

The wp_posts table has a post_content_filtered column that plugins can use to cache expensive post content filters. The idea is that when you display the page, you don’t read post_content but you read post_content_filtered. This is nice, but it won’t solve your search problem because WordPress by default only looks at post_content and post_title.

You can however do it the other way around: store the editor content in post_content_filtered and the rendered page in post_content (update it periodically with a cron job). There are filters that are called before the post is edited, you can use them to pass post_content_filtered instead of post_content to the editor. So the user will see no difference, but the performance and the search experience will be improved.