Issue #3514451 by jastraat: Provide default strings for template types

src/Controller/ChooseSectionFromLibraryController.php

@@ -149,8 +149,8 @@ class ChooseSectionFromLibraryController implements ContainerInjectionInterface
     ];
 
     // Use configured labels.
-    $sectionLabel = $this->config->get('section_label');
-    $templateLabel = $this->config->get('template_label');
+    $sectionLabel = $this->config->get('section_label') ?? 'Section';
+    $templateLabel = $this->config->get('template_label') ?? 'Template';
     $template_types = [
       'any' => $this->t('- Any -'),
       'section' => $sectionLabel,

src/Form/AddSectionToLibraryForm.php

@@ -155,8 +155,8 @@ class AddSectionToLibraryForm extends ContentEntityForm {
 
     if (isset($form['actions']['submit'])) {
       // Use configured labels.
-      $sectionLabel = strtolower($this->config->get('section_label'));
-      $templateLabel = strtolower($this->config->get('template_label'));
+      $sectionLabel = strtolower($this->config->get('section_label') ?? 'section');
+      $templateLabel = strtolower($this->config->get('template_label') ?? 'template');
       if ($this->templateType === 'template') {
         $form['actions']['submit']['#value'] = $this->t('Add :templateLabel', [':templateLabel' => $templateLabel]);
       }
@@ -240,7 +240,7 @@ class AddSectionToLibraryForm extends ContentEntityForm {
    *   Title to use for the route.
    */
   public function titleCallback(string $template_type = 'section'): string {
-    $label = $this->config->get($template_type . '_label');
+    $label = $this->config->get($template_type . '_label') ?? 'Section';
     return $this->t('Add %type to Library', ['%type' => $label]);
   }
 

src/SectionLibraryRender.php

@@ -25,8 +25,8 @@ class SectionLibraryRender implements TrustedCallbackInterface {
     if (isset($elements['layout_builder'])) {
       $sections = $elements['layout_builder'];
       $config = \Drupal::config('section_library.settings');
-      $section_label = strtolower($config->get('section_label'));
-      $template_label = strtolower($config->get('template_label'));
+      $section_label = strtolower($config->get('section_label') ?? 'section');
+      $template_label = strtolower($config->get('template_label') ?? 'template');
 
       $url_options = [
         'attributes' => [