Tag Archive: WordPress

Aug 08 2010

Archives for Custom Post Types in WordPress

When you create a new post type in WordPress using register_post_type(), WordPress does not automatically create a page for listing the archives of that post type. It’s possible to create one, though, without too much hassle.

For example, you can create an post type called article, and set the permalink for that post type to articles (i.e., an article will have a URL like http://example.com/articles/my-article-title).

Where do you go for a list of all articles, though? You might assume http://example.com/articles/, but you would be assuming erroneously. You could create a page with the slug articles and use a custom template for that page, but that doesn’t work with paging (e.g., http://example.com/articles/page/2/).

Instead, you need to fiddle with WordPress’s rewrite rules. (And thanks to Andrew Wilson for helping me understand this.)
Continue reading →

Posted by Jonathan Brinley

Category: Coding

Tags: , ,

4 Comments

May 26 2010

Limit to One Post on WordPress Front Page

Let’s say you have a WordPress blog. You only want one post to appear on the front page of that blog. But, you want all other pages (e.g., the second page, category pages, monthly archives, etc.) to display more than one (be it 5, 10, or whatever you chose on your “Reading Settings” page). The first part is easy, the latter has a few pitfalls to be aware of.

First, we’re going to call query_posts to modify the query a bit. We only want this on the home page, so we wrap it in an if statement:

global $wp_query;
if ( is_home() && !is_paged() ) {
  query_posts(
    array_merge(
      $wp_query->query,
      array('posts_per_page'=>1)
    )
  );
}

is_home() will be TRUE if you’re on the main blog page; !is_paged() verifies that we’re on the first page (because is_home() is still TRUE on subsequent pages (e.g.http://example.com/page/2/)).
Continue reading →

Posted by Jonathan Brinley

Category: Coding

Tags: , ,

2 Comments

May 20 2010

Custom Permalinks for Custom Post Types in WordPress 3.0+

Update 2010-10-04: See Understanding Rewrite Tags for a somewhat more helpful treatment of the subject.

I’ve been playing around with WordPress 3.0 to create a bug/issue-tracking plugin (i.e., using WP to track bugs, not to track WP bugs (although it could conceivably do that)). More details about the plugin will be forthcoming, but now is as good a time as any to share the solution to one problem I came across.

Creating New Post Types and Taxonomies

When you create a new post type, you use the register_post_type function. When you create a new post type through that function, WP creates a new rewrite rule base on the name you give the post type. In my case, I’ve created an issue post type, so all issues, by default, will have the permalink /issue/%issue%/ (where %issue% is replaced with the post slug). Using the rewrite argument to register_post_type, you can change the beginning of the permalink to something different (e.g., /bugs/%issue%/) should you so desire.
Continue reading →

Posted by Jonathan Brinley

Category: Coding

Tags: , ,

52 Comments

Nov 28 2009

Save Time with sed

When I develop WordPress sites, I find that I end up repeating many identical tasks for each site. The phrase “repeating identical tasks” should (and does) set off alarms: This should be automated! To that end, I’m trying to learn some more command line tools for doing tasks that I currently use a GUI for.

One such task is migrating my development database to the staging/production server. Basically a mysqldump from my local database that I can then import on another server. A key thing to watch out for with WordPress, though, is the base URL for your site. If you’re serving a site from localhost while you develop it, you’ll need to change every occurrence of localhost in your database to the base URL for the new server.

sed is a command line tool for doing just that job. It runs a regular expression search on the input and outputs the replacement. Example:

$ echo "localhost" | sed "s/localhost/www.example.com/g"
www.example.org

Pipe your mysqldump through sed to have an SQL file ready for your new server.

$ mysqldump -uusername -ppassword database_name | sed "s/localhost/www.example.com/g" > database.sql

This way I avoid having to open the SQL file in a text editor, doing a global search and replace, and re-saving.

Posted by Jonathan Brinley

Category: Coding

Tags: , , , ,

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Nov 17 2008

Custom Thumbnails WordPress Plugin

When you upload images into WordPress, it automatically creates smaller derivative images to serve as thumbnails. You have little control over these derivatives, aside from setting their maximum dimensions. If you upload any non-image media (e.g., a PDF, a video, an MP3, a tarball, etc.), you don’t get any thumbnail, for fairly obvious reasons.

Let’s say you want more control over your image thumbnails, or you would like to have thumbnails attached to your other uploads. You would need to install a plugin like the Custom Thumbnails plugin I just wrote.

What it does

WordPress associates each upload with a post or a page, using the item’s post_parent attribute. This plugin adds a field to the editing screen for your upload, allowing you to associate it with a “Parent Item”. Once thus associated, any time WordPress requests the thumbnail image of the parent item, it will retrieve the thumbnail image you uploaded, instead.

How it works

Writing this plugin took me much farther into the bowels of WordPress than I had reached before. As it turns out, I needed to use four completely undocumented filters to achieve the effect I wanted. Continue reading →

Posted by Jonathan Brinley

Category: Coding

Tags: , ,

15 Comments