Grabbing Dynamically Generated XML

[DVigneault]

Hey all--

 

So I've got a php script that generates an xml page, which is working, as follows:

 

<?php header ("Content-Type:text/xml");

echo '<?xml version="1.0" encoding="UTF-8"?>';

?>

//Functions to generate xml

 

I'm then trying to grab some of that data in another php script.  In the past, when the xml was hard-coded (file extension .xml), I've used the following:

 

$xml = new SimpleXMLElement(file_get_contents(/path/to/file));

 

When I try to use this to grab my dynamically-generated xml page above (file extension .php), I get a bunch of SimpleXMLElement::__construct() warnings.

 

Sorry in advance if this is a naive question--I'm sure what I'm doing wrong will be glaringly obvious to the people reading this forum.

 

Best,

 

--Davis

[requinix]

Put the logic that generates the XML as a string in some common place. Then use that in both scripts: the one script calls header() and outputs the XML, the other uses it for whatever.

[DVigneault]

Thanks!  So I think understand how to store the hard-coded part of my XML as a string...

 

<?php
$xmlstr = <<<XML
//Some hard-coded XML
XML;
?>

 

...but what about XML I'm generating from a database?  So far I've just been getting it from a database and echoing it like this:

 

    $con = new mysqli($host, $username, $password, $database);
    
        $result = $con->query("SELECT stuff");
        mysqli_close($con);
        $row = mysqli_fetch_array($result);
        while ($row = mysqli_fetch_array($result)) {
                echo '<parent>';
                echo '<child1>' . $row['something'] . '</child1>' . PHP_EOL;
                echo '<child2>' . $row['somethingelse'] . '</child2>' . PHP_EOL;
                echo '</parent>' . PHP_EOL;

[requinix]

Put it all into a variable instead of echoing it.

[DVigneault]

So I've got it outputting XML using ob_start(), ob_get_contents, and ob_end_clean(), as follows:

 

$xml1 = <<<XML

<urlset> //and some hard-coded XML

XML;

ob_start()
    $con = new mysqli($host, $username, $password, $database);
    
        $result = $con->query("SELECT stuff");
        mysqli_close($con);
        $row = mysqli_fetch_array($result);
        while ($row = mysqli_fetch_array($result)) {
                echo '<parent>';
                echo '<child1>' . $row['something'] . '</child1>' . PHP_EOL;
                echo '<child2>' . $row['somethingelse'] . '</child2>' . PHP_EOL;
                echo '</parent>' . PHP_EOL;

$xml2 = ob_get_contents()

ob_end_clean()

$xml3 = '</urlset>';

$sitemap = $xml1 . $xml2 . $xml3;

 

Printing $sitemap with the xml header works, but...

 

$sitemapXML = new SimpleXMLElement($sitemap);

foreach ($sitemapXML->path->to->element as $var) {
    echo $var->whatiwant;
    }

 

...gives me an error, saying that I'm supplying an invalid argument.

 

Thanks for bearing with me...

[Christian F.]

First and foremost, you should have done what requinix said in his/her last post. All that output buffering and multiple variable use is completely unnecessary.

$sitemap = <<<XML

<urlset> //and some hard-coded XML

XML;

$con = new mysqli($host, $username, $password, $database);
$result = $con->query("SELECT stuff");
$row = mysqli_fetch_array($result);

while ($row = mysqli_fetch_array($result)) {
$sitemap .= '<parent>';
$sitemap .= '<child1>' . $row['something'] . '</child1>' . PHP_EOL;
$sitemap .= '<child2>' . $row['somethingelse'] . '</child2>' . PHP_EOL;
$sitemap .= '</parent>' . PHP_EOL;
}

$sitemap .= '</urlset>';

 

The less code you use to accomplish your goal, (generally) the easier it'll be to understand and maintain it.

 

As for your error: What, exactly, is the error message and what line of your code triggers it? Also, how does your XML look like when completely generated?

[DVigneault]

Thanks for the help, ChristianF--I didn't realize that you could append to a variable like that.

 

The output looks like:

 

<?xml version="1.0" encoding="UTF-8"?>
<urlset  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://www.sitemaps.org/schemas/sitemap/0.9 http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd"
         xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
   <url>
      <loc>http://example.com</loc>
      <lastmod>2012-07-30</lastmod>
      <changefreq>monthly</changefreq>
      <priority>0.5</priority>
   </url>
   //More <url></url> elements
</urlset>

 

In the code-block I gave in my last post, the error is on the foreach statement:

 

foreach ($sitemapXML->path->to->element as $var) {

 

and it says that I'm supplying an invalid argument.

 

Warning: Invalid argument supplied for foreach() in path/to/what/i/just/wrote on line 5.

 

Searching on google says that this could mean that I'm not supplying it with an array (and, infact, I just found the is_array() function, and is_array($sitemapXML) returns false).

 

Thanks again for your help, everyone.

[Christian F.]

I'd recommend running a var_dump ($sitemapXML) just before that foreach loop, to see what kind of data's in that variable. Should help you track down the real issue.

 

You're welcome, by the way. Glad we could be of assistance.

[DVigneault]

var_dump() helped alot--I've got it working!  The problem, it seems, was that I included the <urlset> parent element in my foreach path.  When I got rid of that, everything worked like a charm.  :-)

[Christian F.]

Good to hear that you got it working, and happy to be of assistance.

Thanks for sharing the solution to the problem as well.