DisplayLogictest.php

<?php

class Page extends Sitetree {
  public function getCMSFields(){
      $this->beforeUpdateCMSFields(function (FieldList $fields) {

            /**
             * DECLARE FIELDS
             */
            $bannerStylesDropdown = DropdownField::create('BannerStyle', 'Style', [
                'None'               => 'None',                  // /about-us/
                'DomainBanner'       => 'Domain banner',         // /domain/
                'SmallImage'         => 'Small image',           // /email/
                'TallImage'          => 'Tall image',            // /email/
                'SimpleCentered'     => 'Simple centered',       // /about-us/policies/
                'CallToActionBottom' => 'Bottom call to action', // /email/backup-mx/
                'CallToActionInline' => 'Inline call to action', // /web-hosting/
                'TripleActionButton' => 'Three action buttons'   // /web-hosting/diy-website-builder/
            ]);

            $bannerTitleField = TextField::create('BannerTitle', 'Banner title');

            $bannerBackgroundField = UploadField::create('BannerBackgroundImage', 'Background image')
                ->setFolderName('Images/banners/backgrounds')->setAllowedFileCategories('image');

            $bannerButtonOneField   = LinkField::create('BannerButtonOneID', 'Button one');
            $bannerButtonTwoField   = LinkField::create('BannerButtonTwoID', 'Button two');
            $bannerButtonThreeField = LinkField::create('BannerButtonThreeID', 'Button three');

            $bannerCallToActionTextField = TextField::create('BannerCallToActionText', 'Call to action text');

            $bannerSubContentField = HtmlEditorField::create('BannerContent', 'Banner content')->setRows('6');

            /**
             * DECLARE DISPLAY LOGIC
             */
            $bannerTitleField->displayUnless('BannerStyle')->isEqualTo('None');
            $bannerBackgroundField->displayUnless('BannerStyle')->isEqualTo('None')
            ->end();

            $bannerButtonOneField
                ->displayIf('BannerStyle')->isEqualTo('CallToActionBottom')
                ->orIf('BannerStyle')->isEqualTo('CallToActionInline')
                ->orIf('BannerStyle')->isEqualTo('TripleActionButton')
                ->orIf('BannerStyle')->isEqualTo('DomainBanner')
                ->end();

            $bannerButtonTwoField
                ->displayIf('BannerStyle')->isEqualTo('TripleActionButton')
                ->orIf('BannerStyle')->isEqualTo('DomainBanner')
                ->end();

            $bannerButtonThreeField->displayIf('BannerStyle')->isEqualTo('TripleActionButton')->end();

            $bannerCallToActionTextField
                ->displayIf('BannerStyle')->isEqualTo('CallToActionBottom')
                ->orIf('BannerStyle')->isEqualTo('CallToActionInline')
                ->end();

            $bannerSubContentField
                ->displayIf('BannerStyle')->isEqualTo('SimpleCentered')
                ->orIf('BannerStyle')->isEqualTo('CallToActionBottom')
                ->orIf('BannerStyle')->isEqualTo('CallToActionInline')
                ->orIf('BannerStyle')->isEqualTo('TripleActionButton')
                ->end();

            /**
             * ADD FIELDS TO TAB
             */
            $fields->addFieldsToTab('Root.PageBanner', [
                $bannerStylesDropdown,
                $bannerTitleField,
                $bannerButtonOneField,
                $bannerButtonTwoField,
                $bannerButtonThreeField,
                $bannerCallToActionTextField,
                $bannerBackgroundField,
                $bannerSubContentField
            ]);
        });
        
        return parent::getCMSFields();
  }
}