Starting August 15th, the AWS Product Advertising API, as the former E-Commerce Service is now called, will only accept signed requests. The plugin will stop working if you don’t update. Thus I needed to re-engineer a few functions of my WordPress Amazon Machine Tags Plugin.

What you need to do is:

• Update to version 3.0 of the plugin.
• If you didn’t adapt any files just overwrite them. If you customized the CSS or XSL files, take care that you don’t overwrite yours. Also the XSL namespace must reflect the API version used in the plugin (2009-07-01), i.e. xmlns:aws= "http://webservices.amazon.com/ AWSECommerceService/ 2009-07-01"
• Get your Secret Access Key in addition to your existing Access Key ID. Your future requests will be signed using the secret key.
• Go to the plugin’s admin interface and enter the secret key.
• Some people experienced a few minutes where the items didn’t show up, instead they got the untransformed XML code. After a few minutes the problem resolved itself. My guess is that Amazon cached the XSL files, the versions mismatched, therefore the XML wasn’t transformed. That’s why I renamed the XSL files so that the new ones will be used. If you want to be sure, also delete the cached files amtap-aws-items-for-post-*.html in your wp-content/cache directory.

If you encounter any problems with the update, re-install the old version and let me know what went wrong so that we can fix it together until August 15th.

You can also support the plugin by translating it. There’s an empty PO file in the package. With a tool such as Poedit it’s fairly easy to translate everything. Thanks.

1. Let’s start with the simplest transformation, pulling the number of people who have bookmarked your post on del.icio.us. There are two components: one line of PHP code to insert the result in the footer of a page (found in template file single.php), and a few lines of XSLT for the transformation:

   1. <?php inlineRSS(
   2. 'delicious-incoming-' . $id,
'http://feeds.delicious.com/rss/url?url=' . get_permalink(), 60, 'inline-rss-linked.xslt');
   3. ?>

   The function inlineRSS() takes four arguments: the filename where you want to cache the result, the feed URI, the time to cache in minutes, and the filename of the transformation stylesheet. The latter has to be in the same directory as inlineRSS.php (the plugin).

   1. <xsl:template match="/rdf:RDF">
   2. <xsl:if test="count( rss:item ) &gt; 0">
   3. Saved by <span class="linked-in"><xsl:value-of select="count( rss:item )" /></span> other people.
   4. </xsl:if>
   5. </xsl:template>

   Download: inline-rss-linked.xslt

2. In the sidebar of this blog you see a section “current reading” which displays my latest five del.icio.us entries I have tagged with show-in-blog. Because I’m too lazy to add a description on del.icio.us there is just the title and the tags, minus “show-in-blog.” Here is the code for sidebar.php:

   1. <?php inlineRSS(
   2. 'delicious-links',
'http://feeds.delicious.com/rss/ your-delicious-name/show-in-blog', 60, 'inline-rss-delicious.xslt');
   3. ?>

   Of course “your-delicious-name” needs to be replaced.

   Download: inline-rss-delicious.xslt

3. Finally there is a list of my upcoming events, including microformatted semantic information. The XSLT is a little longer, but not really complicated. You just need to replace the upcoming ID with your own.

   1. <?php inlineRSS(
   2. 'upcoming',
'http://upcoming.yahoo.com/ syndicate/v2/ my_events/ 123456', 60, 'inline-rss-upcoming.xslt');
   3. ?>

   Download: inline-rss-upcoming.xslt

I’d like to point out that this is certainly not the only, and perhaps not even the best way to implement feeds into your site, but it’s pretty convenient once you’ve installed inlineRSS.

Chris Heilmann approaches the issue with a client side plugin to distribute tasks from the server to the client. His JavaScript is insofar unobtrusive as the list of inline del.icio.us links is replaced with an external link to his del.icio.us category, but then you give away the responsibility that the list is accessible as well. That’s why I would prefer a server side solution.

Ed Eliot has written a script to create a very pretty server side del.icio.us badge that I highly recommend, but it’s not as universal as the inlineRSS plugin, and it’s not a WordPress plugin to begin with (the same applies to his neat SimpleRSS script). But both Chris’ and Ed’s solutions are decent alternatives to take into consideration.