<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<rss version="2.0"   
     xmlns:yweather="http://xml.weather.yahoo.com/ns/rss/1.0" 
     xmlns:geo="http://www.w3.org/2003/01/geo/wgs84_pos#">
 <channel>
 <title>Yahoo! Weather - Cambridge, MA</title>
<link>http://us.rd.yahoo.com/dailynews/rss/weather/
Cambridge__MA/*http://weather.yahoo.com/forecast/USMA0066_f.html</link>
 <description>Yahoo! Weather for Cambridge, MA</description>
 <language>en-us</language>
 <lastBuildDate>Wed, 28 Nov 2007 2:54 pm EST</lastBuildDate>

 <ttl>60</ttl>
 <yweather:location city="Cambridge" region="MA" country="US" />
 <yweather:units temperature="F" distance="mi" pressure="in" speed="mph" />
 <yweather:wind chill="38" direction="350" speed="9" />
 <yweather:atmosphere humidity="43" visibility="1609"
                      pressure="30.38" rising="1" />
  <yweather:astronomy sunrise="6:50 am" sunset="4:14 pm" />
 
 <image>
 <title>Yahoo! Weather</title>
 <width>142</width>
 <height>18</height>
 <link>http://weather.yahoo.com/</link>
 <url>http://l.yimg.com/us.yimg.com/i/us/nws/th/main_142b.gif</url>
 </image>

 <item>
 <title>Conditions for Cambridge, MA at 2:54 pm EST</title>

  <geo:lat>42.38</geo:lat>
 <geo:long>-71.12</geo:long>
  <link>http://us.rd.yahoo.com/dailynews/rss/weather/
Cambridge__MA/*http://weather.yahoo.com/forecast/USMA0066_f.html</link>
 <pubDate>Wed, 28 Nov 2007 2:54 pm EST</pubDate>
 <yweather:condition text="Mostly Cloudy" code="28" temp="43" 
 date="Wed, 28 Nov 2007 2:54 pm EST" />
 <description><![CDATA[
<img src="http://l.yimg.com/us.yimg.com/i/us/we/52/28.gif" /><br />
 <b>Current Conditions:</b><br />
 Mostly Cloudy, 43 F<BR /><BR />
 <b>Forecast:</b><BR />
  Wed - Sunny. High: 45 Low: 31<br />
  Thu - PM Showers. High: 48 Low: 29<br />
 <br />
<a href="http://.........html">Full Forecast at 
   Yahoo! Weather</a><BR/>
 (provided by The Weather Channel)<br/>
 ]]></description>
 <yweather:forecast day="Wed" date="28 Nov 2007" low="31" high="45" 
                                    text="Sunny" code="32" />

<yweather:forecast day="Thu" date="29 Nov 2007" low="29" high="48" 
             text="PM Showers" code="39" />
  <guid isPermaLink="false">USMA0066_2007_11_28_14_54_EST</guid>
 </item>
</channel>
</rss><!-- p4.weather.sp1.yahoo.com compressed 
Wed Nov 28 12:03:12 PST 2007 -->

                    
<rss version="2.0"
  xmlns:mesh="http://www.hisown.com/NameSpaces/Mesh/20071203">
   <channel>
        <title>People</title>
        <item>
            <guid>Simpsons:/Homer_J_Simpson</guid>
            <title>Homer Jay Simpson</title>
          <link>http://en.wikipedia.org/wiki/Homer_Simpson</link>
            <description>Nuclear Plant Drone, Sector 7-G</description>
            <xvcf:... /> <!-- additional details about this person !-->
            <mesh:axon  type="relation" value="wife"> 
           Simpsons:/People/Marjorie_M_Simpson</mesh:axon>
     <mesh:axon  type="relation" value="son"> 
           Simpsons:/People/Bartholomew_J_Simpson</mesh:axon>
     <mesh:axon type="relation" value="father"> 
          Simpsons:/People/Abraham_A_Simpson</mesh:axon>
     <mesh:axon  type="location" value="work"> 
           Simpsons:/Places/Springfield_Nuclear_Power_Plant</mesh:axon>
        </item>
    </channel>
</rss>

                    
<rss version="2.0">
   <channel>
        <title>Places</title>
        <item>
            <guid> Simpsons:/Places/Springfield_Nuclear_Power_Plant</guid>
            <title>Springfield Nuclear Power Plant</title>
            <description>
            </description>
<image>
   <url> http://upload.wikimedia.org/wikipedia/en/6/6e/Snpp.gif</url>
  <title>Springfield Nuclear Power Plant</title>
 </image>
<link> http://en.wikipedia.org/wiki/Springfield_Nuclear_Power_Plant</link>
            <!-- additional details about this location, if any !-->
          <mesh:axon type="relation" value="proprietor">
                  Simpsons:/People/Charles_Montgomery_Burns</mesh:axon>
           </item> 
    </channel>
</rss>

                    
<rss version="2.0">
   <channel>
        <title>Calendar</title>
        <item>
            <guid>http://jade.hisown.com/Calendar/Meetings/1234</guid>
            <title>Meeting with Mr. Burns</title>
            <description>
            </description>
            <xics: /> <!-- additional details about this event !-->
<mesh:axon type="location" value="place"> 
Simpsons:/Places/Springfield_Nuclear_Power_Plant</mesh:axon>  
          <mesh:axon type="relation" value="participant">
                  Simpsons:/People/Homer_J_Simpson </mesh:axon>
          <mesh:axon type="relation" value="participant">
                  Simpsons:/People/Charles_Montgomery_Burns</mesh:axon>
           </item> 
    </channel>

</rss>

                    
function get_elements($xml, $element,$multiple)
{
 if ($multiple) { 
       /* Return ALL matches of this element in the $xml provided. 
        * Results will be returned as an array or arrays
        */ if ($multiple) {
       $item = preg_match_all("#<$element(|[^>]*)>(.*)</$element>#msU",
                               $xml,
                              $matches,PREG_PATTERN_ORDER);
        
       /* Trim whitespace. This could've been done in the RegExp, */
       /* but you can also use PHP's trim() function for that.     */
            for ($i = 0;
             $i < count ($matches[2]);
             $i++)
            {
                $matches[2][$i] = trim ($matches[2][$i]);
             } /* end for */
           }
          else
          {
          $item = preg_match("/<$element(|[^>]*)>(.*)<\/$element>/msU",
                             $xml,
                             $matches);
          $matches[2] = trim($matches[2]);
 }

      /* 
       * When you get here, $matches is either an array of arrays, or a 
       * single array, in the following format:
       *     
       *   [0] => Entire pattern matched  
       *   [1] => "", or attributes of this element (if any) (| [^>]*)
       *   [2] => Element content (corresponding to (.*)
       * 
       * You thus choose to return [2] = Element contents, or array of  
       * matched elements' contents.
       */  
   return ($matches[2]); /* Element content */
}

                    
function get_specific_element($feed, $child, $value)
{
  $items = get_elements($feed, "item",true);
  if (!$items) { echo "What are you feeding me? No items here!\n"; 
                 return(false);}
  for ($i = 0 ; $i < count ($items);$i++){
     /* to get child elements, simply call on parent element, 
      * with child name as argument 
      */
  
   $val = (get_elements($items[$i],"$child",false)); 
   if ($val == trim($value)) {return ($items[$i]); } ;
     }
     return(false);
}

                    

$feed = get_channel ($feed_url);
$desired_child = /* Whatever, obtain from user */;
$desired_value = /* Whatever, obtain from user */;
$elem = get_specific_element($feed, 
                             $desired_child, 
                             $desired_value);

/* Have some fun with this element: */
$title = (get_elements($elem,"title",false));
$description = (get_elements($elem,"description",false));
/* do something with title and description */
      ...
/* get zero or more connections (axons) this element has ..*/
$axons = (get_elements($elem,"mesh:axon",true));

                    
function get_feed($url)
{
 /* open the feed locally */
 $fp = fopen ($url, "r");

$content = fread($fp, filesize($url));

 return ($content);
}

                    
$contacts_feed = get_feed ("simpsons_contacts.xml");
$engagements_feed = get_feed ("simpsons_engagements.xml");
$places_feed = get_feed ("simpsons_places.xml");

                    

$engs = get_elements($engagements_feed, "item",true);

foreach ($engs as $eng)
{
  $title = (get_elements($eng,"title",false));

 echo ("Got Engagement: $title\n");
}

                    
$engs = get_elements($engagements_feed, "item",true);

foreach ($engs as $eng)
{

  $title = (get_elements($eng,"title",false));

  echo ("Got Engagement: $title\n");

  $axons = (get_elements($eng,"mesh:axon",true));

  foreach ($axons as $ax)
  {
    if (strstr($ax, "Simpsons:/People")) {
      /* Lookup this person */
      $part = get_specific_element($contacts_feed,
                                   "guid",
                                   $ax);

      if (!$part) { echo ($ax . " Not found\n");}
      else {

            $title = (get_elements($part,"title",false));
            echo ("Participant: $title\n");
          }
    }
  }

                    
$contacts_feed = get_feed ("simpsons_contacts.xml");
$contacts = get_elements($contacts_feed,"item",true);
$common_axons = Array();
foreach ($contacts as $contact)
{
  $title = get_elements($contact,"title",false);
  echo ("Got contact: $title<BR/>\n");
  $axons = (get_elements($contact,"mesh:axon",true));
  foreach ($axons as $ax)
  {
    /* Lookup these axons in the $common_axons */
    $cax_count = count ($common_axons);
    for($cax_no = 0;
            $cax_no < $cax_count;
            $cax_no++)
      {
         if ($common_axons[$cax_no] == $ax)
          {
             echo ("Bingo! Commonality found: $ax\n");
             exit(0);
          }
      }
     /* Add anyway */
     $common_axons [count($common_axons)] = $ax;
  } 
} /* end foreach*/

                    
Got contact: Homer Jay Simpson
Got contact: Charles Montgomery_Burns
Bingo! Commonality found: Simpsons:/Places/Springfield_Nuclear_Power_Plant