...

Awenda

http://ontarioparks.com/english/awen.html

-79.991000,44.784600

$url_index = 'http://ontarioparks.com/english/markers.xml';

require('../curl.php');
$curl = new CURL();
$curl->enableCache();

// fetch page, strip HTTP headers
$text_response = strstr($curl->get($url_index), '');
$xml = new SimpleXMLElement($text_response);

$url_base = 'http://www.ontarioparks.com/english/';
$marker_data = array();

foreach($xml->marker as $marker) {
$page = (string)$marker['url'];

// Some parks don't actually have a page.
if ('sorry.html' == $page) {
$desc = '(No data available about this park)‘;
} else {
$page_data = $curl->get($url_base . $page);
// extract info here; build $desc
}

$marker_data[] = array(
‘name’ => (string)$marker[’park’],
‘desc’ => $desc,
‘ll’ => (string)$marker[’lng’] . ‘,’ . (string)$marker[’lat’]
);
}

Quetico is a protected, pristine wilderness retreat of international acclaim west of Lake Superior on the Canada-U.S. border. The park’s tangled network of lakes once formed water routes travelled by Ojibway and fur traders. Now it is primarily the destination of experienced canoeists seeking solitude and rare glimpses of wildlife by cascading waterfalls, glassy lakes and endless forests. The park is accessible at four points by canoe and two by car (Dawson Trail Campground and Lac la Croix Ranger Station).
Bringing your own supply of firewood to the park this summer? Please read this.
 appears nowhere else but here, which makes it the best candidate we’ve got. This wouldn’t really be acceptable as a permanent solution, but we’re only running this once to generate our file, and we can tweak it as many times as it takes to get it right.

if (preg_match('#
.*?(.*?)

.*?

#is’, $page_data, $match)) {
$paragraph = trim(strip_tags($match[1]));
}

That regex may look scary as night, but the key part is that it grabs the first paragraph inside the specified td, and dot meta-character can include newlines. I only strip_tags it to get rid of the image, from those parks that have it.
Scraping out the activities and facilities is slightly more involved, but it’s the same principle at work, only in two stages. The first stage grabs the table surrounding them, and then a preg_match_all snatches each individual one. You can see it in action in the full code link at the bottom of the post. If there’s interest, I’ll put up a future article about regular expressions, specifically tailored to the art of scraping.
KML Output
Once I had everything in the big $marker_data array, it was just a matter of doing the actual generating KML part. You can see that I use short tags here, since it’s a template situation. You shouldn’t use them in portable code, but if it’s your own scripts, it can really turn up the readability and help distinguish PHP from markup.

'; ?>

Ontario Parks

]]>



It would have been possible to use SimpleXML or DOM to generate this XML, but it’s a fairly simple example
Saving To A File
When I was debugging all this, I’d let it simply output to the browser, where I could make a visual inspection. Once it came time to run it on Google Maps and Google Earth, I had it saved to a file for me, a task most easily accompished with output buffering:

 // start buffering

// do output ...



Once the file ends, the buffer gets written out to the screen anyways, but it’s also captured and saved to a file.
Limitations of KML
As stated yesterday, there are some fairly significant limitations on KML, particularly in the Google Maps implementation. The most glaring of these is the filesize limit, which could be overcome in part by just sending the points in batches and withholding infoWindow contents until specifically requested. Other points to consider:

You can’t use custom icons. There are 250 common ones that ship with Maps and Earth, which you can reference, although we didn’t bother in this case. This is a limitation that will hopefully be lifted in the near future, especially given that KML can already make external image references for overlays.
You can’t control everything. For example, the name field will become a tooltip in Earth, but it’s only a sidebar label in Maps. It is possible to do tooltips in a full mashup, of course, as demonstrated in Chapter 8 of the book, but the Maps implementation of KML doesn’t include this yet.
You can’t use JavaScript in the information bubbles, nor can you use the Google Maps tabbed infowindow. It would have been cool to also grab each park’s photograph, as well as the information about facilities and activities, but this data simply wouldn’t all fit in a single infowindow.

These limitations may be frustrating, but they’re hardly deal-breakers. For those dozens of mashups where you only need a few simple points plotted, why not just publish KML?
Full source here: Generate.php