PHP DOM parser get data from a span - php

Question

I am trying to use DOM to get the days and times and also the rooms (im actually getting everything in my script but its getting these two im having trouble with) from the following batch of HTML:
</td><td class="call">
<span>12549<br/></span>View Book Info
</td><td>
<span id="ctl10_gv_sectionTable_ctl03_lblDays">F:1000AM - 1125AM<br />T:230PM - 355PM</span>
</td><td class="room">
<span id="ctl10_gv_sectionTable_ctl03_lblRoom">KUPF106<br />KUPF106</span>
</td><td class="status"><span id="ctl10_gv_sectionTable_ctl03_lblStatus" class="red">Closed</span></td><td class="max">20</td><td class="now">49</td><td class="instructor">
Schoenebeck Kar
</td><td class="credits">3.00</td>
</tr><tr class="sectionRow">
<td class="section">
101<br />
Here is what I have so far for finding days
$tracker =0;
// DAYS AND TIMES
$number = 3;
$digit = "0";
while($tracker<$numSections){
$strNum = strval($number);
$zero = strval($digit);
$start = "ctl10_gv_sectionTable_ctl";
$end = "_lblDays";
$id = $start.$zero.$strNum.$end;
//$days = $html->find('span.$id');
$days=$html->getElementByTagName('span')->getElementById($id);
echo "Days : ";
echo $days[0] . '<br>';
$tracker++;
$number++;
if($number >9){
$digit = "1";
$number=0;
}
}
as you can see from the HTML, the site im parsing has pretty unique ID's for some of its spans (ctl10_gv_sectionTable_ctl03_lblRoom). As I only posted 1 section's HTML block, what you don't see is that the code for the next class section is identical except for the "ctl03" part, which is what all the extra code I have takes care of, just so no one is thrown off by it.
I've tried a few different ways but can not seem to get the days (i.e. "1000AM - 1125AM") or the rooms (i.e. KUPF106). The rest of the stuff is pretty simple to grab but these two don't have class identifiers or even a td identifier. I think I just need to know how to use the value I have in $id as the specific span id I am looking for? If so can someone show me how to do that?

Answer 1

This:
$html->getElementByTagName('span')->getElementById($id);
makes no sense. getElementByTagName returns a DOMList, which does not have a getElementById method.
I think you mean $html->getElementById($id);, but I can't be sure because I don't know what $html is.
Once you have the element, you can get the text value with $element->textContent if you don't need to walk among the text nodes.
Have you considered using DOMXPath for your parsing task? It's probably much easier and clearer.

Answer 2

Simple Html Dom should be avoided unless you're using Php version <= 4. The built in Dom functions in Php5 use the much more reliable libxml2 library.
The proper way to iterate that html is to first identify the rows to iterate and then write xpath expressions to pull the data relative to that row.
$dom = new DOMDocument();
#$dom->loadHTML($html);
$xpath = new DomXpath($dom);
foreach($xpath->query("//tr[#class='sectionRow']") as $row){
echo $xpath->query(".//span[contains(#id,'Days')]",$row)->item(0)->nodeValue."\n";
echo $xpath->query(".//span[contains(#id,'Room')]",$row)->item(0)->nodeValue."\n";
echo $xpath->query(".//span[contains(#id,'Status')]",$row)->item(0)->nodeValue."\n";
}