Issue #3003685 by matsbla, r.e.younan: Create option to make secondary exposed...

Issue #3003685 by matsbla, r.e.younan: Create option to make secondary exposed form options open by default

config/schema/better_exposed_filters.exposed_form.schema.yml

@@ -60,3 +60,6 @@ better_exposed_filters.general:
     secondary_label:
       type: label
       label: 'Secondary options label'
+    secondary_open:
+      type: boolean
+      label: 'Secondary options is open'

src/Plugin/views/exposed_form/BetterExposedFilters.php

@@ -98,6 +98,7 @@ class BetterExposedFilters extends InputRequired {
         'input_required' => FALSE,
         'allow_secondary' => FALSE,
         'secondary_label' => $this->t('Advanced options'),
+        'secondary_open' => FALSE,
       ],
       'sort' => [
         'plugin_id' => 'default',
@@ -287,6 +288,17 @@ class BetterExposedFilters extends InputRequired {
         ],
       ],
     ];
+    $form['bef']['general']['secondary_open'] = [
+      '#type' => 'checkbox',
+      '#default_value' => $bef_options['general']['secondary_open'],
+      '#title' => $this->t('Secondary option open by default'),
+      '#description' => $this->t('Indicates whether the details element should be open by default.'),
+      '#states' => [
+        'visible' => [
+          ':input[name="exposed_form_options[bef][general][allow_secondary]"]' => ['checked' => TRUE],
+        ],
+      ],
+    ];
 
     /*
      * Add options for exposed sorts.
@@ -728,6 +740,7 @@ class BetterExposedFilters extends InputRequired {
         ],
         '#type' => 'details',
         '#title' => $bef_options['general']['secondary_label'],
+        '#open' => $bef_options['general']['secondary_open'],
         // Disable until fields are added to this fieldset.
         '#access' => FALSE,
       ];