I’ve just wrote my first WordPress public plugin, that I’m licensing under GPL v3. This post is to make it public. I’m writing in English because the WordPress plugin directory asks me to provide a plugin page to host the files there and I’ll provide the URL of this post. Update: The plugin is now in the WordPress plugin directory: wordpress.org/extend/plugins/retrospective/

The website of the brazilian newspaper O Estado de São Paulo has a nice way to display news in a retrospective-style (check this screenshot or this link — Flash required).

Wouldn’t it be nice if we could display WordPress posts in our pages and categories in the same way just by using a shortcode? The possibilities are many. That’s why I wrote the Retrospective plugin for WordPress.

It has at least two advantages over the version you just saw:

1. Does not require Flash (its implementation uses only CSS and JavaScript/jQuery)
2. Has a option to respect the (time-)scale of the posts.

Its use is very simple. Wherever you add the shortcode [retrospective] the plugin will draw that cool retrospective. The shortcode supports several attributes:

• count — limit the number of posts to be displayed (default = 10; use -1 to display all)
• cat — display posts with category IDs comma-separated (default = display all posts)
• width — the width of the timeline in pixels (default = 600)
• delay — the time of the focus change animation in milisseconds (default = 1000)
• scale — if set, respect the time scale in the distances between the points in the timeline (default = false)
• image_width, image_height — the dimensions of the thumbnail images in pixels (default = 300×180)
• image_border_size — the size of the image’s border in pixels (default = 7)
• image_border_color — the color of the image’s border in hexa RGB (default = 000000)
• image_margin — the space between the images (default = 5)
• date_format — the date format in PHP format (default = d/m/Y)

Some screenshots

Here is a screenshot from juntos.org.br with scale=true (in the link you can see it working):

And here is a screenshot from a fresh WordPress install (TwentyEleven theme without modifications):

Customizing

Post thumbnails

For better results, I suggest always adding post thumbnails to your posts and using registered image sizes in image_width and image_height attributes.

Styling retrospectives

The generated HTML is very easy to style (but just be careful with margins and paddings, they’re set with !important attribute — I did it to try not to break with any theme). Here is a sample:

<div id="retro-uniquehash" class="retrospective">
  <!-- TIMELINE -->
  <ul class="time">
    <li rel="0">
      <a href="permalink" style="left:0px;"><span>date</span></a>
    </li>
    <li rel="1">
      <a href="permalink" style="left:300px;"><span>date</span></a>
    </li>
    <li rel="2">
      <a href="permalink" style="left:600px;"><span>date</span></a>
    </li>
  </ul>

  <!-- PHOTOS -->
  <div class="photos">
    <ul>
      <li rel="0">
        <a href="permalink" title="title"
          ><img src="file" class="wp-post-image"
        /></a>
      </li>
      <li rel="1">
        <a href="permalink" title="title"
          ><img src="file" class="wp-post-image"
        /></a>
      </li>
      <li rel="2">
        <a href="permalink" title="title"
          ><img src="file" class="wp-post-image"
        /></a>
      </li>
    </ul>
  </div>

  <!-- POSTS -->
  <ul class="posts">
    <li rel="0">
      <a href="permalink" title="title">
        <h2>Title <span>(date)</span></h2>
        <p>Excerpt</p>
      </a>
    </li>
    <li rel="1">
      <a href="permalink" title="title">
        <h2>Title <span>(date)</span></h2>
        <p>Excerpt</p>
      </a>
    </li>
    <li rel="2">
      <a href="permalink" title="title">
        <h2>Title <span>(date)</span></h2>
        <p>Excerpt</p>
      </a>
    </li>
  </ul>
</div>

Styling a specific retrospective

The generated hash takes in consideration all the attributes sent to the shortcode and also how many retrospectives appeared before in the parsing of the actual page. I made it that way to allow users to set up two exactly equal retrospectives in the same page. Because of that, I don’t recommend setting styles for #retro-uniquehash. I think a reasonable solution for this issue is to make add an outer container.

Download

Here is the code for download: retrospective.zip

* Warning: Please consider I’m using a bazaar approach here. Be aware that the plugin probably has a lot of bugs (and please tell me if you catch any).

I hope you enjoy it. Have fun and please let me have your feedback! :)