XML Reference Guide

In other guide sections, I've made the case for the Semantic Web, I've shown you an example of it in use in Google Base, and I've talked about microformats, the so-called (lowercase) semantic web. And all of this is fine, but what we really need is an easy way to produce this information on a regular basis.

If you're a blogger, and thus someone who regularly contributes content to the web, you can try StructuredBlogging. StructuredBlogging is a plug-in for two of of the most popular blogging programs, Wordpress and Movable Type, that makes it easy to create content that is easily analyzed. The StructuredBlogging initiative is also looking to implement microformats, so you can expect greater interoperation between the two of them in the future.

So let's look at how this works. The first step is to go to http://www.structuredblogging.org/download.php and download the StructuredBlogging plug-in for your blogging tool. At the time of this writing, the most recent version is 1pre15.

Once you download the plug-in, you'll need to install it. Instructions for both Wordpress and Movable Type are online, but since I use Movable Type, that's what we'll look at here.

Assuming that you have all of the prerequisites (Movable Type 3.2, MySQL, the XML::Parser Perl module and the LWP::UserAgent Perl module), start by installing the actual software. Unpack the archive file to your hard drive, and then copy all of the files from the plugins directory to the plugins directory of your MT installation. Make sure permissions are set such that the files are readable by your web server.

The StructuredBlogging plug-in enables you to add files such as images to some types of postings, so next you'll need somewhere to put them. Create a directory and make sure the web server can write to it. The actual name and location is immaterial; you'll be telling the plug-in where to find it when you do the configuration. That's the next step.

From the main menu of your Movable Type installation, choose the PLUGINS entry in the right hand column. You should see a listing for the new plugin, along with a Show Settings link on the right hand side. If the Show Settings link does not appear, edit the plugins/StructuredBlogging/StructuredBlogging.pl file as follows:

… author_link => 'http://www.broadbandmechanics.com/', version => '1.0pre15', config => \&configure_plugin_settings, config_template => sub { $structuredblogging->load_tmpl('settings_blog.tmpl') }, settings => new MT::PluginSettings([ ['blog_amazon_url', { Default => 'us' }], ['blog_amazon_affiliate'], …

Click the Show Settings link and enter the appropriate information into the form:

If you don't have an Amazon affiliate ID, that's all right, but it's certainly to your advantage to get one. The plugin inserts this value into any Amazon URLs that reference items you are reviewing. If someone clicks on that link, and then purchases an item, you get paid. Of course, if you really don't want to get one, you can leave it blank. (Or feel free to use my affiliate ID (thevanguardsc-20) if you're feeling generous.)

The OutputThis.org entries pertain to a site that enables you to simultaneously publish your postings to other blogs and destinations. Currently this site is still in beta, and configuring for it is not required.

Now you're ready to create an actual posting.

Creating structured postings

The whole idea behind StructuredBlogging is the thought that data can be marked up in an intelligent way, so it has to be entered in such a way that the plugin understands what the data means. In other words, you can't simply enter everything into one big paragraph and expect the software to figure it out. To that end, if you click on the New Entry button in the Movable Type management interface, you will see a number of new options in the left-hand navigation, including New Review, New List, and New Audio Post. Clicking New Review, gives you the opportunity to choose from a number of different options:

Each type of review has its own fields. For example, it doesn't make any sense to specify the Director of a journal article. For the sake of creating an example, let's create a new Book review:

If you have all of the prerequisites on your server -- specifically, LWP::UserAgent -- all you have to do is enter a title and click the Lookup link next to it. A small window will pop up enabling you to choose from appropriate items as listed on Amazon.com, and if you find the item you're reviewing, selecting it populates the rest of the entries on the page. The ones that involve your opinions, of course, such as the rating and the actual review, will still be left blank.

Complete your review and save the entry. (Note: do not use the "preview" option in Movable Type.)

Fixing the templates

Now, even though you've created a review, or any other type of StructuredBlogging post, if you actually view the pages of your blog, you will see a blank entry. This is because the post is not stored in the normal database location, so we have to adapt the Movable Type templates so they know to look for data stored by the StructuredBlogging plugin.

To do that, go back to the blog administration page and click Configure -> Templates. We'll start by making the post appear on the homepage of the blog. Under the Indexes tab, click the Main Index and add the following code:

...
<MTEntryCategories glue=" | ">
   <a href="<$MTCategoryArchiveLink$>"><$MTCategoryLabel$></a>
</MTEntryCategories>

</span>
 
   <$MTEntryBody$>

   <MTStructuredBloggingHTML>
   <MTStructuredBloggingXML>

          Technorati tags:   <MTEntryTags>
  <a href="http://www.technorati.com/tag/<$MTTag encode_url="1"$>"
    rel="TAG" title="TAG:<$MTTag$>"><$MTTag$></a> | 
  </MTEntryTags>

     <br /> <br />

   <MTEntryIfExtended>

   <div class="extended" style="margin-bottom: 10px"><a href="<$MTEntryPermalink$>#more">Continue reading "<$MTEntryTitle$>"</a></div><br />

   </MTEntryIfExtended>
…

Note that the actual placement of these two tags (which we'll discuss in a moment) will vary according to how your template is laid out, but the important part is that the content is near your <$MTEntryBody$> tag. The instructions on the StructuredBlogging web site will tell you to place these tags inside the <MTEntryIfExtended> element, but if you do, the information won't show up because these posts aren't extended entries.

Click the Archives tab and perform the same steps for the Category- and Date-based and Individual Entry archive templates.

You'll also want to add this information to your RSS feed, and/or to your Atom feed, if you have one. To do that, go back to the Indexes tab and edit the appropriate template as follows:

...
<description><$MTEntryBody encode_xml="1"$>
<MTStructuredBloggingHTML encode_xml="1">
<MTStructuredBloggingXML encode_xml="1"></description>
...

Seeing the results

Okay, so what does all of that actually mean? Let's look at the actual generated page:

All of the information is here, though you'll probably want to adjust the styling somewhat. But let's look at what actually happens on the backend. The two tags we added produced the following code in the actual page:

...
<div class="blogbody">

<a name="000772"></a>

<h3 class="title">Changing my life in seven days</h3>

<span style="margin-bottom: 10px; font-size: smaller;"><a href="http://www.chaosmagnet.com/blog/archives/cat_personal.html"
>Personal</a></span>

<!-- ******* MTStructuredBloggingHTML code starts here ******** -->

<div id="sbentry_772">

  <div class='hreview x-wpsb-review-book'>
     <div>

        <h3 class='item fn'><a class='url' href='http://www.amazon.com/exec/obidos/ASIN/1400082870/thevanguardsc-20/102-6251743-4557719?%5Fencoding=UTF8&camp=1789&link%5Fcode=xm2'>Change your life in seven days</a></h3>

         <p><div><img src="https://ec1.images-amazon.com/images/P/1400082870.01._SCTHUMBZZZ_.jpg"/></div></p>

         <div><b>Rating</b>: <span class="rating">5</span> out of 5<div class="sb-fullstar"> </div><div class="sb-fullstar"> </div><div class="sb-fullstar"> </div><div class="sb-fullstar"> </div><div class="sb-fullstar"> </div></div>

         <p><b>Author</b>: Paul McKenna</p>
         
         <p><b>Year</b>: 2005</p>

         <p><b>Category</b>: Personal development</p>
         <p><b>Publisher</b>: Harmony</p>
         <p><b>Price</b>: 14.95</p>

         <p><b>ISBN</b>: <span class='Z3988' title='ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:book&rft.isbn=1400082870'>1400082870</span></p>
      </div>

      <div class='description'>With a title like "Change Your Life in Seven Days", expectations are pretty high for a book like this.  But I have to say, this book really lives up to the promise of its title.  I've never seen any book that so clearly pointed out in not just what I was doing, but also how I was reacting to everything around me.  This book makes everything so clear that you will wonder why you didn't do this years ago. Buy this book!</div>
      <p><b>Tags</b>: personal development, self-help</p>
   </div>

</div>

<!-- ******** MTStructuredBloggingHTML code ends here ******** -->

<!-- ******** MTStructuredBloggingXML code starts here ******** -->

<script type="application/x-subnode; charset=utf-8">
<!-- the following is structured blog data for machine readers. -->
<subnode alternate-for-id="sbentry_772" xmlns:data-view="http://www.w3.org/2003/g/data-view#" data-view:transformation="http://structuredblogging.org/subnode-to-rdf-interpreter.xsl" xmlns="http://www.structuredblogging.org/xmlns#subnode">
<xml-structured-blog-entry xmlns="http://www.structuredblogging.org/xmlns">

<generator id="mtsb-772" type="x-mtsb-post" version="1"/>
<review><subject year="2005" isbn="1400082870" publisher="Harmony" name="Change your life in seven days" url="http://www.amazon.com/exec/obidos/ASIN/1400082870/thevanguardsc-20/102-6251743-4557719?%5Fencoding=UTF8&camp=1789&link%5Fcode=xm2" image="http://ec1.images-amazon.com/images/P/1400082870.01._SCTHUMBZZZ_.jpg" author="Paul McKenna" price="14.95" category="Personal development" /><rating min="0" max="5">5</rating><description>With a title like "Change Your Life in Seven Days", expectations are pretty high for a book like this.  But I have to say, this book really lives up to the promise of its title.  I've never seen any book that so clearly pointed out in not just what I was doing, but also how I was reacting to everything around me.  This book makes everything so clear that you will wonder why you didn't do this years ago. Buy this book!</description><tags>personal development, self-help</tags></review></xml-structured-blog-entry>

</subnode>
</script>

<!-- ******** MTStructuredBloggingXML code ends here ******** -->

If you read the previous entry on microformats, much of this information is going to look familiar. The StructuredBlogging plugin simply takes the information then outputs it in the appropriate microformat format.

What's more, the MTStructuredBloggingXML tag adds the XML representation, making it even easier for aggregators and other applications to analyze the data.

The end result is that it becomes fairly straightforward to enter structured data, enabling you and every other everyday blogger to more easily contribute to the semantic web.