Parsing DOM with PHP

Here's a dirty script that parses the XML feed provided by Environment Canada.

$data = file_get_contents("http://dd.weatheroffice.ec.gc.ca/citypage_weather/xml/AB/s0000047_e.xml");
$weather = new SimpleXMLElement($data);

$weather_data->location = (string) $weather->location->name;
$weather_data->date = (string) $weather->dateTime[1]->textSummary;
$weather_data->text = (string) $weather->currentConditions->condition;
$weather_data->forecastAbbreviated = (string) $weather->forecastGroup->forecast->abbreviatedForecast->textSummary;
$weather_data->forecast = (string) $weather->forecastGroup->forecast->textSummary;
$weather_data->pressure = (string) $weather->currentConditions->pressure;
$weather_data->temp = (string) $weather->currentConditions->temperature;

$forecasts = array();
foreach($weather->forecastGroup->forecast as $forecast) {
		$forecasts[] = array(
				"period" => (string)$forecast->period,
				"forecast" => (string)$forecast->textSummary,
				"text" => (string)$forecast->abbreviatedForecast->textSummary,
				"pop" => (int)$forecast->abbreviatedForecast->pop,
				"temperature" => (int)$forecast->temperatures->temperature,
				"windchill" => (int)$forecast->windChill->calculated,
				"icon" => (string)$forecast->abbreviatedForecast->iconCode
		);
}
$weather_data->forecasts = $forecasts;


$icon = "http://weather.gc.ca/weathericons/" . $weather->currentConditions->iconCode . ".gif";
$weather_data->icon = $icon;

$weather_data->source = "Environment Canada";

For something more complicated, you may want to take a look into XPath which allows you to navigate and search DOM elements.

For example, I used the following script to scrape the workrooms provided by the libCal service.

function parse_schedule($html) {
        $dom = new DOMDocument();
        $dom->loadHTML($html);

        $xpath = new DOMXpath($dom);


        $rooms = [];
        $bookings = $xpath->query("//*[@id='s-lc-rm-tg-rnames']/*");
        foreach($bookings as $el) {
                $room_number = trim($el->textContent);
                // nonbreaking space utf8 to ascii
                $room_number = trim($room_number, "\xc2\xa0");

                if (trim($room_number) != "") {
                        $rooms[] = $room_number;
                }
        }


        $hours = [];
        $hour_elements = $xpath->query("//*[@class='lc_rm_hours']/div");
        foreach($hour_elements as $el) {
                $hours[] = $el->textContent;
        }


        $bookings = [];
        $schedule = $xpath->query("//*[@id='s-lc-rm-scrolltb']/*/*/*[@class='lc_rm_b']|//*[@id='s-lc-rm-scrolltb']/*/*/*[@class='lc_rm_a']|//*[@id='s-lc-rm-scrolltb']/*/*/*[@class='lc_rm_u']"); // /*[@class=lc_rm_b|@class=lc_rm_u|@class=lc_rm_a]");
        foreach($schedule as $el) {
                $bookings[] = $el->getAttribute('class');
        }

        if (count($bookings) != count($rooms) * count($hours)) {
                echo "Item count mismatch...";
                echo "Got " . count($bookings) . " bookings and expected " . count($rooms) . " x " . count($hours) ;
                echo "\n";
                exit;
        }


        $schedule = [];
        $i = 0;
        foreach($rooms as $room) {
                $schedule[$room] = [];

                foreach($hours as $hour) {
                        $dateparsed = date_parse($hour);

                        $schedule[$room][ $dateparsed['hour'] ] = class_to_status($bookings[$i]);
                        $i++;
                }

        }

        return $schedule;
}