Listing items from XML File

rctneil · February 28, 2010, 11:54am

Hello,
Today I ahve restarted working (for the time ebing anyway) on some work with XML which I am having difficulty with. I ahve the following PHP page:

<?php
session_start();
$user_id = $_SESSION['user_id'];

require_once('db.php');

echo "<h2>My Questions</h2>";

$sql = "SELECT id FROM questions WHERE userid = '$user_id' AND type = 'text'";

$result = mysql_query($sql);

while($questionids = mysql_fetch_array($result)){
//----------------------------------------------------------
//use simplexml to find all questions with the ids from xml file
$new_result = array();
 
$xml = simplexml_load_file('xml/text_questions.xml');
 
foreach ($xml->question_list as $question)
{
    if (in_array((integer) $question->id, $result))
    {
        $result[] = $question->name;
    }
}
//----------------------------------------------------------------
}

$xml = simplexml_load_file('xml/text_questions.xml'); 

foreach($xml as $question){
    echo 'QID #'.$question->id.': '.$question->text.'<hr />';

}
?>

and as you can see with the sql queiry above, it is meant to find the id’s of questions which have a user id equal to the id of the user currently signed in, ie, from the session variable. It is then meant to search through an XML file to find all the questions where the question id was returned from the sql query.

For some reason, the above script, is just displaying all questions from the XML file instead of only those for that specific user.

The XML file is structured as follows:

<?xml version="1.0"?>
<question_list>
	<question>
		<id>
			1
		</id>
		<text>
			What is a Cat?
		</text>
	</question>
</question_list>

Please can someone help me figure out what is going wrong here?

Jake_Arkinstall · February 28, 2010, 12:32pm

Look at what the last section of code, after the loop, is doing.

Also be careful about the variables you’re using inside that loop

rctneil · February 28, 2010, 12:53pm

Morning Jake!, You really are a great help on here.

I see that I have set it to load the XML file twice so ahve merged it toegther:

while($questionids = mysql_fetch_array($result)){
//----------------------------------------------------------
//use simplexml to find all questions with the ids from xml file
$new_result = array();
 
$xml = simplexml_load_file('xml/text_questions.xml');
 
foreach ($xml->question_list as $question)
{
    if (in_array((integer) $question->id, $result))
    {
        $result[] = $question->name;
		echo 'QID #'.$question->id.': '.$question->text.'<hr />';
    }
}
//----------------------------------------------------------------
}

?>

It’s now giving me no questions outputted at all. I am a bit confused as to how the simpleXML lines are working. Would it be possible for you to explain what the code is doing in english first and then I can try and figure the last bit out?

Jake_Arkinstall · February 28, 2010, 1:04pm

I’m sure you could find that out yourself, with a bit of use of the PHP Manual

[hint]The $result variable holds the mysql query, not an array.[/hint]

rctneil · February 28, 2010, 1:15pm

Right,

Just tried altering it and came up with this:

require_once('db.php');

echo "<h2>My Questions</h2>";

$sql = "SELECT id FROM questions WHERE userid = '$user_id' AND type = 'text'";

$result = mysql_query($sql);

while($questionids = mysql_fetch_array($result)){
//----------------------------------------------------------
//use simplexml to find all questions with the ids from xml file
$new_result = array();

while($row=mysql_fetch_assoc($result))
{ 
$new_result[]=$row;
}
 
$xml = simplexml_load_file('xml/text_questions.xml');

foreach ($xml->question_list as $question)
{
    if (in_array($question->id, $new_result))
    {
		echo 'QID #'.$question->id.': '.$question->text.'<hr />';
    }
}
//----------------------------------------------------------------
}

?>

It still doesn;t show any questions though. I tried looking at the manual for simpleXML but it just does not seem SIMPLE for me. The code I ahev just does not seem to relate to what in the manual in any way. And I don;t quite understand what lines such as this:

$xml->question_list as $question

are doing as question is a child element of question_list so I would ahve expected it would be written like:

$xml->question_list->question as $question

?

rctneil · February 28, 2010, 3:10pm

Latest code:

<?php
session_start();
$user_id = $_SESSION['user_id'];

require_once('db.php');

echo "<h2>My Questions</h2>";

$sql = "SELECT id FROM questions WHERE userid = '$user_id' AND type = 'text'";

$result = mysql_query($sql);

$xml = simplexml_load_file('xml/text_questions.xml');

$questionids = array();
while($row = mysql_fetch_assoc($result)){
    $questionids[] = $result['id'];
}
$questions = $xml->question;

var_dump($questions);
echo '<br /><br />';
var_dump($questionids);
echo '<br /><br />';
var_dump($xml);
	
foreach ($xml->question_list as $question){
	if (in_array($question->id, $questionids)){
		printf('QID #%s: %s<hr />', $question->id, $question->text);
	}
}

?>

Output:

My Questions
object(SimpleXMLElement)#2 (2) { ["id"]=> string(8) " 1 " ["text"]=> string(21) " What is a Cat? " } 

array(1) { [0]=> NULL } 

object(SimpleXMLElement)#1 (1) { ["question"]=> array(18) { [0]=> object(SimpleXMLElement)#4 (2) { ["id"]=> string(8) " 1 " ["text"]=> string(21) " What is a Cat? " } [1]=> object(SimpleXMLElement)#5 (2) { ["id"]=> string(8) " 2 " ["text"]=> string(25) " What is your name? " } [2]=> object(SimpleXMLElement)#6 (2) { ["id"]=> string(8) " 3 " ["text"]=> string(25) " Where are you now? " } [3]=> object(SimpleXMLElement)#7 (2) { ["id"]=> string(8) " 5 " ["text"]=> string(34) " this text should be entered " } [4]=> object(SimpleXMLElement)#8 (2) { ["id"]=> string(8) " 6 " ["text"]=> string(31) " this is another question " } [5]=> object(SimpleXMLElement)#9 (2) { ["id"]=> string(1) "6" ["text"]=> string(14) "$question_text" } [6]=> object(SimpleXMLElement)#10 (2) { ["id"]=> string(1) "6" ["text"]=> string(13) "Where are we?" } [7]=> object(SimpleXMLElement)#11 (2) { ["id"]=> string(1) "9" ["text"]=> string(20) "Where is Manchester?" } [8]=> object(SimpleXMLElement)#12 (2) { ["id"]=> string(2) "10" ["text"]=> string(12) "who is sara?" } [9]=> object(SimpleXMLElement)#13 (2) { ["id"]=> string(2) "11" ["text"]=> string(6) "tester" } [10]=> object(SimpleXMLElement)#14 (2) { ["id"]=> string(2) "12" ["text"]=> string(6) "tester" } [11]=> object(SimpleXMLElement)#15 (2) { ["id"]=> string(2) "13" ["text"]=> object(SimpleXMLElement)#22 (0) { } } [12]=> object(SimpleXMLElement)#16 (2) { ["id"]=> string(2) "14" ["text"]=> string(21) "what is alisons name?" } [13]=> object(SimpleXMLElement)#17 (2) { ["id"]=> string(2) "15" ["text"]=> string(15) "Where is Imran?" } [14]=> object(SimpleXMLElement)#18 (2) { ["id"]=> string(2) "16" ["text"]=> string(17) "where is beijing?" } [15]=> object(SimpleXMLElement)#19 (2) { ["id"]=> string(2) "17" ["text"]=> string(8) "22222222" } [16]=> object(SimpleXMLElement)#20 (2) { ["id"]=> string(2) "18" ["text"]=> string(19) "where is neil" } [17]=> object(SimpleXMLElement)#21 (2) { ["id"]=> string(2) "19" ["text"]=> string(31) "What type of Object is Emerald?" } } }

XML:

<question_list>
<question>
<id>
1 
</id>
<text>
What is a Cat? 
</text>
</question>
<question>
<id>
2 
</id>
<text>
What is your name? 
</text>
</question>
</question_list>

Jake_Arkinstall · February 28, 2010, 3:26pm

The thing that strikes me here is that you’ve got:

$questions = $xml->question; 
var_dump($questions);

which outputs:

object(SimpleXMLElement)#2 (2) { ... }

Stating that $xml->question is a SimpleXMLElement.

However, when you var_dump($xml):

object(SimpleXMLElement)#1 (1) { ["question"]=> array(18) { ... } ... }

Stating that $xml->question is an array.

Are you sure that this is the current uploaded version?

rctneil · February 28, 2010, 3:27pm

Positive that that is the latest version

Jake_Arkinstall · February 28, 2010, 3:29pm

I don’t know if this is the problem - in fact I doubt it is - but your XML declaration is missing.

Put this at the top of your XML file:

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

rctneil · February 28, 2010, 3:31pm

It did already have that, just that Opera doesn’t show that when viewing an XML document

Jake_Arkinstall · February 28, 2010, 3:36pm

Ok then.

Soooo, forgetting that dodgy error (or perhaps a slip-up on my behalf) and forcing an array:

<?php 
session_start(); 
$user_id = $_SESSION['user_id']; 

require_once('db.php'); 

echo '<h2>My Questions</h2>'; 
$sql = "SELECT id FROM questions WHERE userid = '$user_id' AND type = 'text'"; 
$result = mysql_query($sql); 
$xml = simplexml_load_file('xml/text_questions.xml'); 

$questionids = array(); 

while($row = mysql_fetch_assoc($result)){ 
    $questionids[] = $row['id']; 
}

echo '<h3>MySQL Question IDs: </h3>';
    echo '<ul>';
    foreach($questionids as $qid){
        echo "<li>{$qid}</li>";
    }
    echo '</ul>';
echo '<h3>XML Question IDs:</h3>';
    echo '<ul>';
    foreach ($xml->question as $question){ 
        echo "<li>{$question->id} - ";
        if (in_array($question->id, $questionids)){ 
            //echo "QID #{$question->id}: {$question->text}<hr />";
            echo 'Match';
        }else{
            echo 'No match';
        }
        echo '</li>';
    }
    echo '</ul>';
?>

What is the output?

rctneil · February 28, 2010, 3:42pm

Output:

My Questions
MySQL Question IDs:
19
XML Question IDs:
1 - No match
2 - No match
3 - No match
5 - No match
6 - No match
6 - No match
6 - No match
9 - No match
10 - No match
11 - No match
12 - No match
13 - No match
14 - No match
15 - No match
16 - No match
17 - No match
18 - No match
19 - Match

Jake_Arkinstall · February 28, 2010, 3:47pm

In which case, it is working.

sooo, remove the debug code and uncomment the original output code:

<?php 
session_start(); 
$user_id = $_SESSION['user_id']; 
require_once('db.php'); 

echo '<h2>My Questions</h2>'; 

//Load the IDs from the database into a compact array:
$questionids = array(); 
$sql = "SELECT id FROM questions WHERE userid = '$user_id' AND type = 'text'"; 
$result = mysql_query($sql); 
while($row = mysql_fetch_assoc($result)){ 
    $questionids[] = $row['id']; 
}

//load the XML file and loop - when there's a match, output
$xml = simplexml_load_file('xml/text_questions.xml'); 
foreach ($xml->question as $question){ 
    if (in_array($question->id, $questionids)){ 
        echo "QID #{$question->id}: {$question->text}<hr />";
    }
}
?>

There should be 1 question, #19, output for that user.

rctneil · February 28, 2010, 3:49pm

Excellent, Thanks, the question does show up. I hvae no idea why it didn;t work before. Thanks

AnthonySterling · February 28, 2010, 3:49pm

is thinking someone should check $user_id.

Off Topic:

Doh! That’ll teach me for reading the thread, composing a post then buggering off to make a coffee before submitting!

rctneil · February 28, 2010, 3:50pm

huh?

Topic		Replies	Views
Not printing questions from XML file PHP	14	741	April 14, 2010
Find XML nodes PHP	4	339	February 2, 2010
Query XML file and show pages based on the values PHP	33	3579	March 15, 2015
XML, PHP return all items PHP xml	7	1775	November 18, 2016
Help with loop please PHP	23	1281	February 22, 2011

Listing items from XML File

Related topics