Klasse in Contao 3 überschreiben

Hallo,

ich verzweifle gerade etwas am Namespace-System von Contao 3.1. Und zwar möchte ich die FormSubmit.php aus dem core überschreiben. Da dachte ich mir, ich nutze mal die neue Namespace-Funktionalität und habe eine Erweiterung angelegt mit folgenden Dateien:

config/autoload.ini
config/autoload.php
FormSubmit.php

In autload.php gebe ich Contao einfach die andere Klasse mit:

Code:

---

<?php

ClassLoader::addClasses(array
(
        // Forms
        'Contao\FormSubmit'                => 'system/modules/xmeinmodul/FormSubmit.php',
));

---

Und FormSubmit.php sieht so aus:

Code:

---

<?php

namespace MyNamespace;
use \Contao\FormSubmit as FormSubmitOld;

class FormSubmit extends FormSubmitOld {

        public function generate()
        {
                if ($this->imageSubmit)
                {
                        // Check for version 3 format
                        if ($this->singleSRC != '' && !is_numeric($this->singleSRC))
                        {
                                return '<p class="error">'.$GLOBALS['TL_LANG']['ERR']['version2format'].'</p>';
                        }

                        $objModel = \FilesModel::findByPk($this->singleSRC);

                        if ($objModel !== null && is_file(TL_ROOT . '/' . $objModel->path))
                        {
                                return sprintf('<input type="image" src="%s" id="ctrl_%s" class="submit%s" title="%s" alt="%s"%s%s',
                                                                $objModel->path,
                                                                $this->strId,
                                                                (($this->strClass != '') ? ' ' . $this->strClass : ''),
                                                                specialchars($this->slabel),
                                                                specialchars($this->slabel),
                                                                $this->getAttributes(),
                                                                $this->strTagEnding);
                        }
                }

                // Return the regular button
                return sprintf('<button type="submit" id="ctrl_%s" class="submit%s"%s>%s</button>',
                                                $this->strId,
                                                (($this->strClass != '') ? ' ' . $this->strClass : ''),
                                                $this->getAttributes(),
                                                specialchars($this->slabel));
        }
}

---

Wenn ich ausführe, bekomme ich einen Fatal error:

Code:

---

Fatal error: Class 'Contao\FormSubmit' not found in <...>\system\modules\xmeinmodul\FormSubmit.php on line 15

---

Bin etwas ratlos und hoffe, es kann jemand Licht ins Dunkel bringen ;)

Ciao The_Unknown

Lass dir die autoload.php generieren übers Backend, dann wirst du den Fehler sehen.

OK, er hat mir jetzt das hier generiert und es funktioniert tatsächlich.

Code:

---

<?php

/**
 * Contao Open Source CMS
 *
 * Copyright (c) 2005-2013 Leo Feyer
 *
 * @package Xmrl
 * @link    https://contao.org
 * @license http://www.gnu.org/licenses/lgpl-3.0.html LGPL
 */


/**
 * Register the namespaces
 */
ClassLoader::addNamespaces(array
(
        'MyNamespace',
));


/**
 * Register the classes
 */
ClassLoader::addClasses(array
(
        'MyNamespace\FormSubmit' => 'system/modules/meinmodul/FormSubmit.php',
));

---

Jetzt habe ich eine Klasse in einem eigenen Namespace registriert, ok. Aber woher weiß Contao nun, dass es diese anstatt der eigenen Klasse nehmen soll? Die Klassen liegen doch in völlig verschiedenen Namespaces?

Nun, das ist so in Contao, grob gesagt, er nimmt den ersten Teil weg und registriert alles was danach kommt im globalen Namespace.
Und, er registriert erst die Core Module und dann die externen Erweiterungen.

Würde bei dir nun heißen:

• es greift jemand zu über \FormSubmit : es würde deine Klasse genommen werden, da deine die letzte ist die unter diesen Namen registriert ist.
• es greift jemand zu über \Contao\FormSubmit : es würde die originale Klasse von Contao verwendet werden.

Aah, ok. Sehr gut erklärt, vielen Dank!

Is this still the way to override classes in contao4?

Overriding classes is deprecated. It still works in Contao 4 for some cases but not all. What exactly do you want to do?

Hi Spooky, thank you for the info. I was wondering to what extend it is supported in Contao4 because in Contao3, if I remember it correctly, it was seen as a feature to able to override core classes, back then.
I have an old custom module which overrides contao Search class (Search.php), to eliminate some special chars, words, and char length < 3 filling up DB. I know there is a HOOK `indexPageHook` which due to its position didn't gave me a full advantage.
Anyway now I'm using this hook to achieve the same result in my Contao 4 module, but I've to repeat some part of logic from core class inside my hook.

Zitat:

---

Zitat von Spooky

Overriding classes is deprecated. It still works in Contao 4 for some cases but not all.

---

Do you mean this way is deprecated?

PHP-Code:

---

$GLOBALS['TL_MODEL']['tl_form_field'] = \App\Model\MyCustomModel::class; 


---

That's still supported (though there may be some caveats). What's not supported is overriding classes via the root namespace.

Zitat:

---

Zitat von Spooky

That's still supported (though there may be some caveats). What's not supported is overriding classes via the root namespace.

---

In that case, my example would have no point, because instantiating FormFieldModel is hardcoded in \Contao\Form. I guess that's the caveat... Or is it a bug?