PHP Increment/Decrement value from xml

Question

This is my xml.

    <episodes>
        <episode>
           <series_name>Test</series_name>
            <season_number>1</season_number>
            <episode_number>10</episode_number>
            <episodes_in_season>12</episodes_in_season>
            <notes>Testing</notes>
         </episode>
    </episodes>

What i want to do is get the number of season/episode number and increment or decrement i from that xml and then save it back (i have +/- buttons on my page for season_number and for episode_number, and i am using `$_post for that button).

And here is my code so far.

$xmlDoc = new DOMDocument();
$xmlDoc->load($user);
$xpath = new DOMXpath($xmlDoc);
$test = $xmlDoc->getElementsByTagName('episode')->item(0);

// example for episode number increment / decrement (what i think)

   $number = $test->childNodes->item(2); 

    $increment = $number + 1; 
    $decrement = $number - 1; // example

i am stuck here and i didn't complete it since i can't see whats going on in $number because i am getting this error Object of class DOMElement could not be converted to int.

i have also tried it with (int)$number = $test->childNodes->item(2); but with no luck. And also i am a beginner in php so i might got this thing wrong all together.

edit:

  $eNumber = $xpath->query('episode_number', 'episode')->item(0);
      $esNumber = $xpath->query('episodes_in_season', 'episode')->item(0);
     if ($eNumber == $esNumber)
     {
        echo "You have reached the max episode in season";

     }
     else
     {

     $eNumber->nodeValue++;
     }

it always says i have reached the max episode

I think you posted the wrong XML. You search for tags named 'series' but your example only has 'episode'. — Fabian Schmengler, Feb 04 '13 at 11:39

Álvaro González · Answer 1 · 2013-02-04T12:07:14.057

2

The DOMNodelist::item() method you are using does not return a value (neither string nor integer), it returns a node:

DOMNode DOMNodelist::item ( int $index )

As such (and assuming your Xpath query was correct), you need to access its nodeValue property to read the number. Then, if you cast to integer make sure you do it before you assign the result to a variable:

$number = (int)$test->childNodes->item(2)->nodeValue;

... though it's normally not necessary since PHP will do it for you as soon as you do math:

$foo = '33';
var_dump($foo); // string(2) "33"
$foo++;
var_dump($foo); // int(34)

edited Feb 04 '13 at 12:07

answered Feb 04 '13 at 11:35

Álvaro González

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This does not work. You cannot convert DOMElement objects to int or string, neither implicitly (like in the question) nor explicitly (like in your answer). – Fabian Schmengler Feb 04 '13 at 11:46
1

Probably you were thinking of `SimpleXMLElement` ;-) – Fabian Schmengler Feb 04 '13 at 12:01
@ÁlvaroG.Vicario np tried like fab said and it worked, anyway thank you both. – MePo Feb 04 '13 at 12:07
@fab - You bet I was! Although the question has been answered, I've fixed my answer for the records. – Álvaro González Feb 04 '13 at 12:09
Mind if ask you one more thing... don't want to open another question as it is in topic with this one – MePo Feb 04 '13 at 12:30
@fab and ÁlvaroG.Vicario Mind if ask you one more thing... don't want to open another question as it is in topic with this one (see edit) – MePo Feb 04 '13 at 12:36
1

@MePo - Please read answers carefully. `item(0)` returns an object, you want `item(0)->nodeValue` every time you need the number. Additionally, learn to use `var_dump()`. – Álvaro González Feb 04 '13 at 12:40
ok got it and ty again.. and sorry for troubling you. will do that – MePo Feb 04 '13 at 12:43

score 2 · Accepted Answer · answered Feb 04 '13 at 11:50

2

If $number is the DOMElement corresponding to episode_number, do the following to increment:

$number->nodeValue++;

By the way, instead of $number = $test->childNodes->item(2); I would recommend XPath to always address the correct element:

$number = $xpath->query('episode_number', $test)->item(0);

answered Feb 04 '13 at 11:50

Fabian Schmengler

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Will try that.. will get back to you fab. – MePo Feb 04 '13 at 11:56
Worked like a charm :) ty. Edit: ok will try that also – MePo Feb 04 '13 at 12:00

PHP Increment/Decrement value from xml

2 Answers2