iterating over a Zend_Config #2443

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zfbot opened this Issue Sep 28, 2012 · 12 comments

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@zfbot
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zfbot commented Sep 28, 2012

Jira Information

Original Issue:ZF2-10
Issue Type:Bug
Reporter:meugen
Created:03/23/09
Assignee:DASPRiD
Components:Zend\Config

Description

There are two xml-files.

<?xml version="1.0" encoding="utf-8" ?>
<root>
    <files>
        <file id="index" location="index.html" />
        <file id="main_css" location="css/main.css" />
        <file id="main_js" location="js/main.js" />
    </files>
</root>

and

<?xml version="1.0" encoding="utf-8" ?>
<root>
    <files>
        <file id="index" location="index.html" />
    </files>
</root>

and the sample code:

<?php
    require_once 'Zend/Config.php';
    require_once 'Zend/Config/Xml.php';

    $config = new Zend_config_xml('/path/to/config.xml');
    foreach ($config->files->file as $value)
        echo 'id: '.$value->id.'<br />location: '.
            htmlspecialchars($value->location).'<hr />';
?>

If the {{/path/to/config.xml}} to substitute {{config1.xml}}, then everything works correctly. But if you substitute {{config2.xml}} error

Notice: Trying to get property of non-object in D:\www\index.php on line 7

How can I iterate all items {{file}}, if their number is not known in advance (one or more than one)?

@zfbot
Collaborator
zfbot commented Sep 28, 2012

(Originally posted by: akrabat on 04/05/09)

Can't fix at Zend_Config level. Workaround is to use UTF8 files without a BOM marker.

@zfbot
Collaborator
zfbot commented Sep 28, 2012

(Originally posted by: akrabat on 04/05/09)

(Closed wrong issue!)

@zfbot
Collaborator
zfbot commented Sep 28, 2012

(Originally posted by: akrabat on 04/05/09)

I'm not sure there's any way to resolve this issue due to the other than creating a dummy key to force an array:

<?xml version="1.0" encoding="utf-8" ?>
<root>
    <files>
        <file id="index" location="index.html" />
        <file />
    </files>
</root>

might work, but don't forget to test for id being null.

@zfbot
Collaborator
zfbot commented Sep 28, 2012

(Originally posted by: Patrick van Dissel on 09/02/09)

This issue also exists when using the toArray() method of Zend_Config.
The problem is that you just want the array to ALWAYS have the same layout.
Config files tent to grow and be extended, just like XML files.

In my opinion the Zend_Config API should work the same as the of SimpleXml, here two extended examples and their output:
h2. Using SimpleXML

<?php
// Files with single file element
$xmlString1 = <<<XML
<?xml version="1.0" encoding="utf-8" ?>
<root>
    <files>
        <file>
            <id>index</id>
            <location>index.html</location>
        </file>
    </files>
</root>
XML;

// Files with multiple file elements
$xmlString2 = <<<XML
<?xml version="1.0" encoding="utf-8" ?>
<root>
    <files>
        <file>
            <id>index</id>
            <location>index.html</location>
        </file>
        <file>
            <id>index2</id>
            <location>index2.html</location>
        </file>
    </files>
</root>
XML;

echo "Files with single file element, looping files->file:\n";
$xml1 = new SimpleXMLElement($xmlString1);
foreach ($xml1->files->file as $file) {
    var_dump($file);
    printf("%s: %s\n", 'id', $file->id);
    printf("%s: %s\n", 'localtion', $file->location);
}
echo "Files with single file element, looping files->file->id:\n";
foreach ($xml1->files->file->id as $id) {
    var_dump($id);
    printf("%s: %s\n", 'id', $id);
}

echo "Files with multiple file elements, looping files->file:\n";
$xml2 = new SimpleXMLElement($xmlString2);
foreach ($xml2->files->file as $file) {
    var_dump($file);
    printf("%s: %s\n", 'id', $file->id);
    printf("%s: %s\n", 'localtion', $file->location);
}
echo "Files with multiple file elements, looping files->file->id:\n";
foreach ($xml2->files->file->id as $id) {
    var_dump($id);
    printf("%s: %s\n", 'id', $id);
}
Files with single file element, looping files->file:
object(SimpleXMLElement)#3 (2) {
  ["id"]=>
  string(5) "index"
  ["location"]=>
  string(10) "index.html"
}
id: index
localtion: index.html
Files with single file element, looping files->file->id:
object(SimpleXMLElement)#2 (1) {
  [0]=>
  string(5) "index"
}
id: index
Files with multiple file elements, looping files->file:
object(SimpleXMLElement)#6 (2) {
  ["id"]=>
  string(5) "index"
  ["location"]=>
  string(10) "index.html"
}
id: index
localtion: index.html
object(SimpleXMLElement)#3 (2) {
  ["id"]=>
  string(6) "index2"
  ["location"]=>
  string(11) "index2.html"
}
id: index2
localtion: index2.html
Files with multiple file elements, looping files->file->id:
object(SimpleXMLElement)#4 (1) {
  [0]=>
  string(5) "index"
}
id: index

h2. Using Zend_Config_Xml
possibly a global Zend_Config or other Zend_Config* types issue, I have not tested that_

<?php
set_include_path(
    get_include_path()
    . PATH_SEPARATOR . 'library/'
);

require_once 'Zend/Loader/Autoloader.php';
Zend_Loader_Autoloader::getInstance()->setFallbackAutoloader(true);

// Files with single file element
$xmlString1 = <<<XML
<?xml version="1.0" encoding="utf-8" ?>
<root>
    <files>
        <file>
            <id>index</id>
            <location>index.html</location>
        </file>
    </files>
</root>
XML;

// Files with multiple file elements
$xmlString2 = <<<XML
<?xml version="1.0" encoding="utf-8" ?>
<root>
    <files>
        <file>
            <id>index</id>
            <location>index.html</location>
        </file>
        <file>
            <id>index2</id>
            <location>index2.html</location>
        </file>
    </files>
</root>
XML;

echo "Files with single file element, looping files->file:\n";
$xml1 = new Zend_Config_Xml($xmlString1);
foreach ($xml1->files->file as $file) {
    var_dump($file);
    printf("%s: %s\n", 'id', $file->id);
    printf("%s: %s\n", 'localtion', $file->location);
}
echo "Files with single file element, looping files->file->id:\n";
foreach ($xml1->files->file->id as $id) {
    var_dump($id);
    printf("%s: %s\n", 'id', $id);
}

echo "Files with multiple file elements, looping files->file:\n";
$xml2 = new Zend_Config_Xml($xmlString2);
foreach ($xml2->files->file as $file) {
    var_dump($file);
    printf("%s: %s\n", 'id', $file->id);
    printf("%s: %s\n", 'localtion', $file->location);
}
echo "Files with multiple file elements, looping files->file->id:\n";
foreach ($xml2->files->file->id as $id) {
    var_dump($id);
    printf("%s: %s\n", 'id', $id);
}
Files with single file element, looping files->file:
string(5) "index"
<br />
<b>Notice</b>:  Trying to get property of non-object in <b>D:\www\htdocs\dev\config\config.php</b> on line <b>44</b><br />
id: 
<br />
<b>Notice</b>:  Trying to get property of non-object in <b>D:\www\htdocs\dev\config\config.php</b> on line <b>45</b><br />

localtion: 
string(10) "index.html"
<br />
<b>Notice</b>:  Trying to get property of non-object in <b>D:\www\htdocs\dev\config\config.php</b> on line <b>44</b><br />
id: 
<br />
<b>Notice</b>:  Trying to get property of non-object in <b>D:\www\htdocs\dev\config\config.php</b> on line <b>45</b><br />

localtion: 
Files with single file element, looping files->file->id:
<br />
<b>Warning</b>:  Invalid argument supplied for foreach() in <b>D:\www\htdocs\dev\config\config.php</b> on line <b>48</b><br />
Files with multiple file elements, looping files->file:
object(Zend_Config)#9 (8) {
  ["_allowModifications:protected"]=>
  bool(false)
  ["_index:protected"]=>
  int(0)
  ["_count:protected"]=>
  int(2)
  ["_data:protected"]=>
  array(2) {
    ["id"]=>
    string(5) "index"
    ["location"]=>
    string(10) "index.html"
  }
  ["_skipNextIteration:protected"]=>
  NULL
  ["_loadedSection:protected"]=>
  NULL
  ["_extends:protected"]=>
  array(0) {
  }
  ["_loadFileErrorStr:protected"]=>
  NULL
}
id: index
localtion: index.html
object(Zend_Config)#11 (8) {
  ["_allowModifications:protected"]=>
  bool(false)
  ["_index:protected"]=>
  int(0)
  ["_count:protected"]=>
  int(2)
  ["_data:protected"]=>
  array(2) {
    ["id"]=>
    string(6) "index2"
    ["location"]=>
    string(11) "index2.html"
  }
  ["_skipNextIteration:protected"]=>
  NULL
  ["_loadedSection:protected"]=>
  NULL
  ["_extends:protected"]=>
  array(0) {
  }
  ["_loadFileErrorStr:protected"]=>
  NULL
}
id: index2
localtion: index2.html
Files with multiple file elements, looping files->file->id:
<br />
<b>Warning</b>:  Invalid argument supplied for foreach() in <b>D:\www\htdocs\dev\config\config.php</b> on line <b>61</b><br />

{color:red}note:{color} Output rendered with PHP in error_reporting mode = E_ALL | E_STRICT

@zfbot
Collaborator
zfbot commented Sep 28, 2012

(Originally posted by: akrabat on 09/04/09)

I'm open to ideas on how to solve this without breaking backwards compatibility.

@zfbot
Collaborator
zfbot commented Sep 28, 2012

(Originally posted by: DASPRiD on 09/04/09)

You could just do:

$files = (isset($files->file[0]) ? $files->file : array($files->file));

And then just work with the $files variable as array. That works pretty well.

@zfbot
Collaborator
zfbot commented Sep 28, 2012

(Originally posted by: wimg on 04/28/11)

Although this is fixable, fixing it will always break backwards compatibility.
When a developer knows there's only 1 item, code such as this will be broken :

echo $config->files->file['id'];

Because it will in fact have to become :

$file = $config->files->file->toArray();
echo $file[0]['id'];

I would advise against modifying this for ZF 1.x - not sure how this will be handled in ZF 2, but introducing this backwards incompatibility is not a good idea in any case...

The only other option is to modify just the magic/fluent notation, but that will make things complicated and will cause inconsistency between fluent notation and array notation, which should be avoided.

@zfbot
Collaborator
zfbot commented Sep 28, 2012

(Originally posted by: akrabat on 04/28/11)

One idea I have had is to introduce a children() method that always returns an iterator/array regardless of whether there is is one or many children:

$files = $config->files->children();
foreach ($files as $file) {
    echo $file->id;
}

Thoughts on this approach?

@zfbot
Collaborator
zfbot commented Sep 28, 2012

(Originally posted by: akrabat on 05/26/11)

Moved to ZF2 as likely to involve a BC break.

@zfbot
Collaborator
zfbot commented Sep 28, 2012

(Originally posted by: EvanDotPro on 07/20/12)

Approaching RC1, we need to decide if anything is going to be done about this.

@zfbot
Collaborator
zfbot commented Sep 28, 2012

This issue was ported from the ZF2 Jira Issue Tracker at
http://framework.zend.com/issues/browse/ZF2-10

Known GitHub users mentioned in the original message or comment:
@DASPRiD, @akrabat, @wimg, @EvanDotPro

@DASPRiD DASPRiD was assigned Sep 28, 2012
@ralphschindler
Member

Closing due to inactivity.

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