silverstripe-userforms: Form not showing when Elemental is installed

Please note the following steps were taken on a project with which I have very little familiarity.

The problem (pre-investigation) I have the UserDefinedForm module and Elemental installed. My UserDefinedForm.ss template looks like the following:

$ElementalArea
$Form

However, the $Form is refusing to render and I initially had no ideas on why that wasn’t working.

The problem (post-investigation) So after digging into the code of UserDefinedFormController, I deduced that the index action is blanking out the “Form” property, because $Content defaults to having “$UserDefinedForm” when you create the page.

EDIT: If you don’t know, the $Content field is completely removed / hidden in the CMS when you have Elemental installed. This made discovery of this problem tough!

The proposed solution Add a config that disables the blanking out of the “Form”. Modules like Elemental or Blocks could enable this OOTB.

ie.

public function index(HTTPRequest $request = null)
{
    // Add this vvvv
    if ($this->config()->disable_form_content_interpolation) {
        return [];
    }
    if ($this->Content && $form = $this->Form()) {
        $hasLocation = stristr($this->Content, '$UserDefinedForm');
        if ($hasLocation) {
            /** @see Requirements_Backend::escapeReplacement */
            $formEscapedForRegex = addcslashes($form->forTemplate(), '\\$');
            $content = preg_replace(
                '/(<p[^>]*>)?\\$UserDefinedForm(<\\/p>)?/i',
                $formEscapedForRegex,
                $this->Content
            );
            return [
                'Content' => DBField::create_field('HTMLText', $content),
                'Form' => ''
            ];
        }
    }

    return [
        'Content' => DBField::create_field('HTMLText', $this->Content),
        'Form' => $this->Form()
    ];
}

Why not use Elemental UserForms?

• Maybe you don’t want the client to decide where the Form belongs on their page. (you just want it to be before or after all Elemental blocks)
• Maybe the client creates lots of forms and always forgets to add in the Elemental block. (As they’re used to this kind of workflow as that’s how their site always worked prior to SS4)