Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

php xml code explantion

Posted on 2013-11-14
6
Medium Priority
?
352 Views
Last Modified: 2013-11-16
Please explain why this code works and the object part



 <?php // RAY_temp_rgb192.php error_reporting(E_ALL); echo '<pre>'; // SEE http://www.experts-exchange.com/Web_Development/Web_Languages-Standards/PHP/Q_28287746.html#a39633174 $url = 'http://www.experts-exchange.com/viewCodeSnippet.jsp?refID=39631349&rtid=20&icsi=3'; // THE XML FILE AT THE GIVEN $url IS UNUSABLE, SO IT'S INSERTED HERE $xml = <<<EOD <?xml version="1.0" encoding="UTF-8"?> <urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"> <url> <loc>http://website.com/</loc> <priority>1.0</priority> </url> <url> <loc>http://www.website.com/portfolio/</loc> <priority>0.9</priority> </url> <url> <loc>http://www.website.com/about/</loc> <priority>0.9</priority> </url> <url> <loc>http://www.website.com/contact/</loc> <priority>0.9</priority> </url> <url> <loc>http://www.website.com/portfolio/branding/</loc> <priority>0.8</priority> </url> <url> <loc>http://www.website.com/portfolio/web-wordpress/</loc> <priority>0.8</priority> </url> <url> <loc>http://www.website.com/portfolio/social-media/</loc> <priority>0.8</priority> </url> <url> <loc>http://www.website.com/portfolio/print/</loc> <priority>0.8</priority> </url> <url> <loc>http://www.website.com/portfolio/branding/cabrillo-youth-summer-institute.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/santacruz-popup-artparty.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/red-house.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/what-to-do-in.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/room-service.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/new-evolution.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/film-production-studio.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/rogueIBO.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/booster-bath.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/pilar-macchione.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/katie-mcmahon.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/genesis.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/tequila-jacks.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/em-integrated.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/em.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/orignauxmoose.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/corey-gegner.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/trey-hock.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/nathan-jones.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/morgan-victoria.php</loc> </url> </urlset> EOD; // MAKE AN OBJECT $obj = simplexml_load_string($xml); // USE AN ITERATOR TO RECOVER THE PARTS OF THE URL ARRAY $urlist = array(); foreach ($obj->url as $u) { $l = (string)$u->loc; $p = (string)$u->priority; $d = "$l,$p"; $d = rtrim($d, ','); $urlist[] = $d; } // SHOSW THE WORK PRODUCT print_r($urlist); 

Open in new window

0
Comment
Question by:rgb192
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 2
6 Comments
 
LVL 111

Expert Comment

by:Ray Paseur
ID: 39647992
The code does not work any more.  It worked when I posted it, but it appears to have been modified.  Do you have a copy of the original, with appropriate line breaks and formatting?  I do not keep copies of "RAY_temp_" scripts.
0
 
LVL 14

Expert Comment

by:jb1dev
ID: 39649094
As other comment said, this is really hard to read with the formatting you have posted.

But I gather your question is, how does the inline xml work?
This is using something called a heredoc
See
http://www.tuxradar.com/practicalphp/2/6/3

In your example, the code is using "EOD" (this can be anything, but usually people use EOD as short for "end of document")
So the string:
$xml = <<<EOD

is initialized to all the subsequent text until reaching a single line starting with "EOD"

It then attempts to load that xml document (from the string $xml) using this function:

$obj = simplexml_load_string($xml)

which appears to return an object.
0
 
LVL 111

Expert Comment

by:Ray Paseur
ID: 39649153
Note on HEREDOC... The end-of-document delimiter must start in column 1.  That is one of the reasons for keeping the original formatting.
0
Concerto's Cloud Advisory Services

Want to avoid the missteps to gaining all the benefits of the cloud? Learn more about the different assessment options from our Cloud Advisory team.

 

Author Comment

by:rgb192
ID: 39651078
<?php // RAY_temp_rgb192.php
error_reporting(E_ALL);
echo '<pre>';

// SEE http://www.experts-exchange.com/Web_Development/Web_Languages-Standards/PHP/Q_28287746.html#a39633174

$url = 'http://www.experts-exchange.com/viewCodeSnippet.jsp?refID=39631349&rtid=20&icsi=3';

// THE XML FILE AT THE GIVEN $url IS UNUSABLE, SO IT'S INSERTED HERE
$xml = <<<EOD
<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"> <url> <loc>http://website.com/</loc> <priority>1.0</priority> </url> <url> <loc>http://www.website.com/portfolio/</loc> <priority>0.9</priority> </url> <url> <loc>http://www.website.com/about/</loc> <priority>0.9</priority> </url> <url> <loc>http://www.website.com/contact/</loc> <priority>0.9</priority> </url> <url> <loc>http://www.website.com/portfolio/branding/</loc> <priority>0.8</priority> </url> <url> <loc>http://www.website.com/portfolio/web-wordpress/</loc> <priority>0.8</priority> </url> <url> <loc>http://www.website.com/portfolio/social-media/</loc> <priority>0.8</priority> </url> <url> <loc>http://www.website.com/portfolio/print/</loc> <priority>0.8</priority> </url> <url> <loc>http://www.website.com/portfolio/branding/cabrillo-youth-summer-institute.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/santacruz-popup-artparty.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/red-house.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/what-to-do-in.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/room-service.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/new-evolution.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/film-production-studio.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/rogueIBO.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/booster-bath.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/pilar-macchione.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/katie-mcmahon.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/genesis.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/tequila-jacks.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/em-integrated.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/em.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/orignauxmoose.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/corey-gegner.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/trey-hock.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/nathan-jones.php</loc> </url> <url> <loc>http://www.website.com/portfolio/branding/morgan-victoria.php</loc> </url> </urlset>
EOD;

// MAKE AN OBJECT
$obj = simplexml_load_string($xml);

// USE AN ITERATOR TO RECOVER THE PARTS OF THE URL ARRAY
$urlist = array();
foreach ($obj->url as $u)
{
    $l = (string)$u->loc;
    $p = (string)$u->priority;
    $d = "$l,$p";
    $d = rtrim($d, ',');
    $urlist[] = $d;
}

// SHOSW THE WORK PRODUCT
print_r($urlist);

Open in new window


Sorry, mobile.ee to copy paste PREVIOUSLY
0
 
LVL 111

Accepted Solution

by:
Ray Paseur earned 2000 total points
ID: 39651302
The script uses the SimpleXML class to create an object from the XML string.  In PHP both arrays and objects are iteratible, so you can use foreach() to process objects iteratively, drawing out data elements one at a time in sequence.  That is what we are doing with the $l and $p variables.  In some cases the $p variable does not exists, so after concatenating the $l,$p, we use rtrim() to remove the trailing comma, if any.

Programming with PHP is only about the data, and that is all that PHP does -- transform data from one form to another.  We can use print_r() to visualize the data.  In the case of the $obj variable, it is an object that contains an array of smaller objects.  It looks like this:

SimpleXMLElement Object
(
    [url] => Array
        (
            [0] => SimpleXMLElement Object
                (
                    [loc] => http://website.com/
                    [priority] => 1.0
                )

            [1] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/
                    [priority] => 0.9
                )

            [2] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/about/
                    [priority] => 0.9
                )

            [3] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/contact/
                    [priority] => 0.9
                )

            [4] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/
                    [priority] => 0.8
                )

            [5] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/web-wordpress/
                    [priority] => 0.8
                )

            [6] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/social-media/
                    [priority] => 0.8
                )

            [7] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/print/
                    [priority] => 0.8
                )

            [8] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/cabrillo-youth-summer-institute.php
                )

            [9] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/santacruz-popup-artparty.php
                )

            [10] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/red-house.php
                )

            [11] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/what-to-do-in.php
                )

            [12] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/room-service.php
                )

            [13] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/new-evolution.php
                )

            [14] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/film-production-studio.php
                )

            [15] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/rogueIBO.php
                )

            [16] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/booster-bath.php
                )

            [17] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/pilar-macchione.php
                )

            [18] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/katie-mcmahon.php
                )

            [19] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/genesis.php
                )

            [20] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/tequila-jacks.php
                )

            [21] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/em-integrated.php
                )

            [22] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/em.php
                )

            [23] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/orignauxmoose.php
                )

            [24] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/corey-gegner.php
                )

            [25] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/trey-hock.php
                )

            [26] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/nathan-jones.php
                )

            [27] => SimpleXMLElement Object
                (
                    [loc] => http://www.website.com/portfolio/branding/morgan-victoria.php
                )

        )

)

Open in new window

In the case of the $urlist array, it looks like this:

Array
(
    [0] => http://website.com/,1.0
    [1] => http://www.website.com/portfolio/,0.9
    [2] => http://www.website.com/about/,0.9
    [3] => http://www.website.com/contact/,0.9
    [4] => http://www.website.com/portfolio/branding/,0.8
    [5] => http://www.website.com/portfolio/web-wordpress/,0.8
    [6] => http://www.website.com/portfolio/social-media/,0.8
    [7] => http://www.website.com/portfolio/print/,0.8
    [8] => http://www.website.com/portfolio/branding/cabrillo-youth-summer-institute.php
    [9] => http://www.website.com/portfolio/branding/santacruz-popup-artparty.php
    [10] => http://www.website.com/portfolio/branding/red-house.php
    [11] => http://www.website.com/portfolio/branding/what-to-do-in.php
    [12] => http://www.website.com/portfolio/branding/room-service.php
    [13] => http://www.website.com/portfolio/branding/new-evolution.php
    [14] => http://www.website.com/portfolio/branding/film-production-studio.php
    [15] => http://www.website.com/portfolio/branding/rogueIBO.php
    [16] => http://www.website.com/portfolio/branding/booster-bath.php
    [17] => http://www.website.com/portfolio/branding/pilar-macchione.php
    [18] => http://www.website.com/portfolio/branding/katie-mcmahon.php
    [19] => http://www.website.com/portfolio/branding/genesis.php
    [20] => http://www.website.com/portfolio/branding/tequila-jacks.php
    [21] => http://www.website.com/portfolio/branding/em-integrated.php
    [22] => http://www.website.com/portfolio/branding/em.php
    [23] => http://www.website.com/portfolio/branding/orignauxmoose.php
    [24] => http://www.website.com/portfolio/branding/corey-gegner.php
    [25] => http://www.website.com/portfolio/branding/trey-hock.php
    [26] => http://www.website.com/portfolio/branding/nathan-jones.php
    [27] => http://www.website.com/portfolio/branding/morgan-victoria.php
)

Open in new window

HTH, ~Ray
0
 

Author Closing Comment

by:rgb192
ID: 39653170
The script uses the SimpleXML class to create an object from the XML string.  In PHP both arrays and objects are iteratible, so you can use foreach() to process objects iteratively, drawing out data elements one at a time in sequence.  That is what we are doing with the $l and $p variables.  In some cases the $p variable does not exists, so after concatenating the $l,$p, we use rtrim() to remove the trailing comma, if any.


Thanks
0

Featured Post

Concerto Cloud for Software Providers & ISVs

Can Concerto Cloud Services help you focus on evolving your application offerings, while delivering the best cloud experience to your customers? From DevOps to revenue models and customer support, the answer is yes!

Learn how Concerto can help you.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Things That Drive Us Nuts Have you noticed the use of the reCaptcha feature at EE and other web sites?  It wants you to read and retype something that looks like this. Insanity!  It's not EE's fault - that's just the way reCaptcha works.  But it i…
There are times when I have encountered the need to decompress a response from a PHP request. This is how it's done, but you must have control of the request and you can set the Accept-Encoding header.
Learn how to match and substitute tagged data using PHP regular expressions. Demonstrated on Windows 7, but also applies to other operating systems. Demonstrated technique applies to PHP (all versions) and Firefox, but very similar techniques will w…
The viewer will learn how to look for a specific file type in a local or remote server directory using PHP.

721 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question