Problems with class extending UserDefinedForm in Silverstripe 4 - php

Question

I've been stuck on this for a while now and I can't see where I'm going wrong.
I've made a class that extends the UserDefinedForm so I can have a page that also has a UserDefinedForm on it. The form loads on the page, but it isn't as easy as just saying $Form on the template file, instead I have to make and call the following function:
public function getUserForm() {
$page = UserDefinedForm::get()->byID($this->ID);
$controller = UserDefinedFormController::create($page);
return $controller->Form();
}
So when I call that function on the template it displays the form, however, none of my field rules are applied and when submitting the form it takes me to a blank page with "/finished" appended to the URL: "https://example.com/finished".
Can someone please help me out here, would be much appreciated.
I will put my code down below.
Class extending the UserDefinedForm:
<?php
use SilverStripe\Forms\FieldList;
use SilverStripe\Forms\TextField;
use SilverStripe\Forms\FileHandleField;
use SilverStripe\Core\Injector\Injector;
use SilverStripe\Assets\Image;
use SilverStripe\Forms\HTMLEditor\HTMLEditorField;
use SilverStripe\Forms\GridField\GridField;
use SilverStripe\Forms\GridField\GridFieldConfig_RecordEditor;
use SilverStripe\Forms\DropdownField;
use SilverStripe\UserForms\Model\UserDefinedForm;
use SilverStripe\UserForms\Control\UserDefinedFormController;
use SilverStripe\UserForms\Model\EditableCustomRule;
class Package extends UserDefinedForm {
private static $db = [
'Date' => 'Text',
'Location' => 'Text',
'Availability' => 'Enum(array("Available","Hidden","Sold Out"))',
'Extras' => 'HTMLText',
'NeedTo' => 'HTMLText',
'Price' => 'Text'
];
private static $has_one =[
'Photo' => Image::class,
];
private static $has_many =[
'FileAttachments' => 'PackageFile'
];
private static $many_many = [
'SacredTexts' => 'ImportantText'
];
public function getCMSFields() {
$fields = parent::getCMSFields();
$fields->addFieldToTab('Root.Main', Injector::inst()->create(FileHandleField::class, 'Photo'));
$fields->addFieldToTab('Root.Main', new TextField('Date', 'Date'));
$fields->addFieldToTab('Root.Main', new TextField('Location', 'Location'));
$fields->addFieldToTab('Root.Main', new TextField('Price', 'Price'));
$fields->addFieldToTab('Root.Main', new HTMLEditorField('Extras', 'Extras'));
$fields->addFieldToTab('Root.Main', new HTMLEditorField('NeedTo', 'What you need to know'));
$fields->addFieldToTab('Root.Main', new DropdownField('Availability', 'Availability', singleton('Package')->dbObject('Availability')->enumValues()));
$fields->addFieldToTab('Root.Main', new GridField('SacredTexts', 'Important Texts', $this->SacredTexts(), GridFieldConfig_RecordEditor::create()),'Date');
$fields->addFieldToTab('Root.Main', new GridField('FileAttachments', 'File Attachments', $this->FileAttachments(), GridFieldConfig_RecordEditor::create()),'Content');
return $fields;
}
/* Look up SS4 docs on SS Sitetree URL parse function and what needs to be namespaced */
function onBeforeWrite () {
parent::onBeforeWrite ();
if($this->Name){
$this->Slug = str_replace(' ','-', strtolower($this->Name));;
}
}
public function ShortContent( $word_limit = 20 ) {
$NoHTML = htmlspecialchars_decode(strip_tags($this->NewsText),ENT_QUOTES);
$words = explode( ' ', $NoHTML );
return implode( ' ', array_slice( $words, 0, $word_limit ) );
}
public function ParentEvent(){
return $this->Parent()->URLSegment;
}
public function getUserForm() {
$page = UserDefinedForm::get()->byID($this->ID);
$controller = UserDefinedFormController::create($page);
return $controller->Form();
}
public function hasUserForm() {
if (count($this->getUserForm()->Fields()) > 1) {
return $this->getUserForm();
}
}
}

Answer 1

I figured it out.
Turns out the class controller I was extending to override wasn't working, instead it was referring to the UserDefinedFormController. I fixed it by copying the following function from the UserDefinedForm class:
public function getControllerName()
{
return UserDefinedFormController::class;
}
and copying it into my extended class from UserDefinedForm and renaming the return statement to the name of the class, for example:
public function getControllerName()
{
return PackageController::class;
}