Help with my XML parser....too many results

[anthony522]

I have an XML parser script that I wrote based off a tutorial on the web. The tutorial did a decent job of explaining what the pieces do but it did not explain how I could limit my results. This leaves me with the ability to parse the RSS feed and display it on the page but I'm at the mercy of the RSS feed's length as far as showing the headlines on my site though I only want to show 5. You can see what I'm talking about here: XML Parser script.

I was hoping somebody could take a look at the code below and try and point me in the right direction. I tried to incorporate creating a "counter" variable and then throughing a few if statements around different pieces but had no luck.

I have two goals with this script:

• Limit the script to 5 headlines

• ULTIMATE GOAL: Parse multiple RSS feeds at once and display them in the same script

Without further ado, here's the script:

<?php

$insideitem = false;
$tag = "";
$title = "";
$description = "";
$link = "";

// FUNCTIONS ###############################################################
function startElement($parser, $name, $attrs) 
	{
 _global $insideitem, $tag, $title, $description, $link;
 _if ($insideitem) 
 _	{
 _ _$tag = $name;
 _	} 
 _elseif ($name == "ITEM") 
 _	{
 _ _$insideitem = true;
 _	}
	}

function endElement($parser, $name) 
	{
 _global $insideitem, $tag, $title, $description, $link;
 _if ($name == "ITEM") 
 _	{
 _ _printf("<b><a href='%s' target='_blank'>%s</a></b><br />",
 _ _	trim($link),htmlspecialchars(trim($title)));
 _ _printf("%s<p class=\"gensmall\" />",htmlspecialchars(trim($description)));
 _ _$title = "";
 _ _$description = "";
 _ _$link = "";
 _ _$insideitem = false;
 _ _print "$counter";
 _	}
	}

function characterData($parser, $data) 
	{
 _global $insideitem, $tag, $title, $description, $link;
 _if ($insideitem) 
 _	{
 _ _switch ($tag) 
 _ _	{
 _ _ _case "TITLE":
 _ _ _$title .= $data;
 _ _ _break;
 _ _ _case "DESCRIPTION":
 _ _ _$description .= $data;
 _ _ _break;
 _ _ _case "LINK":
 _ _ _$link .= $data;
 _ _ _break;
 _ _	}
 _	}
	}
// END OF FUNCTIONS #####################################################

$xml_parser = xml_parser_create();
xml_set_element_handler($xml_parser, "startElement", "endElement");
xml_set_character_data_handler($xml_parser, "characterData");
$fp = fopen("http://rss.news.yahoo.com/rss/sports","r")
	or die("Error reading RSS data.");
while ( $data = fread($fp, 4096) )
	{
 _xml_parse($xml_parser, $data, feof($fp))
 _	or die(sprintf("XML error: %s at line %d", 
 _ _xml_error_string(xml_get_error_code($xml_parser)), 
 _ _xml_get_current_line_number($xml_parser)));
	}
fclose($fp);
xml_parser_free($xml_parser);
?>

Update:
Well I was able to limit the RSS feed in 6 story chunks (Why 6, I'm not sure) by using the following with the while statement:

while ( $data = fread($fp, 4096) )
	{
		if ($counter==1)
		{
			xml_parse($xml_parser, $data, feof($fp))
				or die(sprintf("XML error: %s at line %d", 
					xml_error_string(xml_get_error_code($xml_parser)), 
					xml_get_current_line_number($xml_parser)));
			//echo $counter;
			$counter++;
		}

Still looking to cut the feed down further.[/i]

[Norman_Graham]

Hi Anthony

I have a simple solution to this which is on my website. Unfortunately, my employer has just permanently shut down all FTP ports so I can't get the file. Grrrrrrr.

Send a short reply to this and then I'll get an e-mail about it to remind me to send you the file when I get home. It'll have to wait till tomorrow evening, though, because I won't get home until v. late this evening.

If you can wait that long, I have the answer.

Norm

[anthony522]

Great, look forward to seeing your code.

I did notice that if I adjust the "4096" part of my code it alters the "chunks" of the XML that the parser parses at a time. By playing with that I can limit the amount but I'm not sure if this code is still the best solution.

[Shrike]

Surely all you need to do is count the number of times you hit an end tag which closes one 'article' until you have enough, then exit the script?

[Norman_Graham]

Yeah, that's one part of it, Shrike, but the way Anthony's code works, you also have to do the same for the start tags, otherwise the default HTML recreates itself for every entry in the feed but without picking up the content - you get a lot of pointless HTML after the items you actually want.

Anyway, as I say Anthony, I'll give you the finished and tested code tomorrow or you can work it out yourself if you can't be bothered waiting till then. It's not terribly difficult, but it took me a little while to understand why it has to be the way it has to be.

Norm

[anthony522]

I'm still messing with it but as I said, would love to see your code.

[Norman_Graham]

Hi Anthony

As promised:

<?php

class RSSParser {

var $insideitem = false;
var $tag = "";
var $title = "";	
var $description = "";
var $link = "";
var $pubDate = "";
var $itemNumber = 0;

function startElement($parser, $tagName, $attrs) {		
	if ($this->insideitem) {
		$this->tag = $tagName;
	} elseif ($tagName == "ITEM" && $this->itemNumber <= 2) {
		$this->insideitem = true;			
	}
}

function endElement($parser, $tagName) {		
	if ($tagName == "ITEM" && $this->itemNumber <= 2) {			
		printf("<dt><a href='%s' target=\"_blank\">%s</a>\nPublication date:&nbsp;%s</dt>",				trim($this->link),htmlspecialchars(trim($this->title)),htmlspecialchars(trim($this->pubDate)));
		printf("<dd>%s</dd>",htmlspecialchars(trim($this->description)));
		$this->title = "";			
		$this->description = "";
		$this->link = "";
		$this->pubDate = "";
		$this->insideitem = false;
		$this->itemNumber = $this->itemNumber + 1;
	}
}

function characterData($parser, $data) {
	if ($this->insideitem) {
	switch ($this->tag) {
		case "TITLE":
		$this->title .= $data;
		break;			
		case "DESCRIPTION":
		$this->description .= $data;
		break;
		case "LINK":
		$this->link .= $data;
		break;
		case "PUBDATE":
		$this->pubDate .= $data;
		break;
	}
	}
}
}

?>

HTH

Norm

[anthony522]

Thank you Norm.