divide xml into chunks based on url in php - php

Question

I have a robots.txt file
in that i generate dynamic sitemap links.
I get the following links if i run the robots.txt file in the browser.
Here you get 5 sitemap links for each language.
Reason: there are 10 products in database.
i want to show only two products per link. so i divided the total no.of products with no.of products on one page.
Sitemap:http://demo.com/pub/sitemap_products.php?page=1&lang=it_IT
the part in bold is dynamic.
code in: sitemap_products.php
$Qproduct : returns an array of all the products in the db for all the languages.
So the bellow loop generates an xml having links of the products for the language in the sitemap url
for eg.
if the link is
Sitemap:http://demo.com/pub/sitemap_products.php?page=1&lang=it_IT
it will generate all the products present in IT language.
The xml links that are generated now are based on languages that we get from url.
but i want to divide them into chunks of 2 product's xml per sitemap link.
while($Qproduct->next())
{
if(!isset($page_language[$Qproduct->valueInt('language_id')]))
{
$page_language[$Qproduct->valueInt('language_id')] = mxp_get_page_language($MxpLanguage->getCode($Qproduct->valueInt('language_id')), 'products');
}
if($Qproduct->valueInt('language_id') == $QproductLang->valueInt('languages_id'))
{
$string_to_out .= '<url>
<loc>' . href_link($page_language[$Qproduct->valueInt('language_id')], $Qproduct->value('keyword'), 'NONSSL', false) . '</loc>
<changefreq>weekly</changefreq>
<priority>1</priority>
</url>';
}
}
what i wish to do is apply a condition so that it gives me exactly two products links in xml when page=1(see in the sitemap links) instead of all the 10 products link in xml.
similarly if page=2 it should display next 2 products. and so on.
I am a bit confused in the condition that i am supposed to apply.
Please help me out.

Answer 1

First of all, use an XML library to create the XML, not string concatenation. Example:
$loc = href_link($page_language[$Qproduct->valueInt('language_id')], $Qproduct->value('keyword'), 'NONSSL', false);
$url = new SimpleXMLElement('<url/>');
$url->loc = $loc;
$url->changefreq = 'weekly';
$url->priority = 1;
In your case, you can even easily wrap that into a function that just returns such an element and which has two parameters: $Qproduct and $page_language (as string, not array (!)).
But that's just some additional advice, because the main point you ask about is the looping and more specifically the filtering and navigating inside the loop to the elements you're interested in.
First of all you operate on all results by looping over them:
while ($Qproduct->next())
{
...
}
Then you say, that you're only interested in links of a specific language:
while ($Qproduct->next())
{
$condition = $Qproduct->valueInt('language_id') == $QproductLang->valueInt('languages_id');
if (!$condition) {
continue;
}
...
}
This already filters out all elements not interested in. What is left to keep track and decide which elements to take:
$page = 1;
$start = ($page - 1) * 2;
$end = $page * 2 - 1;
$count = 0;
while ($Qproduct->next())
{
$condition = $Qproduct->valueInt('language_id') == $QproductLang->valueInt('languages_id');
if (!$condition) {
continue;
}
$count++;
if ($count < $start) {
continue;
}
...
if ($count >= $end) {
break;
}
}
Alternatively, instead writing this all the time your own, create an Iterator for $Qproduct iteration and the use FilterIterator and LimitIterator for filtering and pagination.