Issue #3002872 Support to add styles and scripts in head tag

src/Form/HeaderForm.php

@@ -0,0 +1,76 @@
+<?php
+
+namespace Drupal\header_and_footer_scripts\Form;
+
+use Drupal\Core\Form\ConfigFormBase;
+use Symfony\Component\HttpFoundation\Request;
+use Drupal\Core\Form\FormStateInterface;
+
+/**
+ * Provide settings page for adding CSS/JS before the end of body tag.
+ */
+class HeaderForm extends ConfigFormBase {
+
+  /**
+   * Implements FormBuilder::getFormId.
+   */
+  public function getFormId() {
+    return 'hfs_header_settings';
+  }
+
+  /**
+   * Implements ConfigFormBase::getEditableConfigNames.
+   */
+  protected function getEditableConfigNames() {
+    return ['hfs_header_scripts.settings'];
+  }
+
+  /**
+   * Implements FormBuilder::buildForm.
+   */
+  public function buildForm(array $form, FormStateInterface $form_state, Request $request = NULL) {
+    $header_section = $this->config('hfs_header_scripts.settings')->get();
+
+    $form['hfs_header'] = [
+      '#type'        => 'fieldset',
+      '#title'       => $this->t('Add Scripts and Styles in Header'),
+      '#description' => $this->t('All the defined scripts and styles in this section would be added just before closing the <strong>body</strong> tag.'),
+    ];
+
+    $form['hfs_header']['styles'] = [
+      '#type'          => 'textarea',
+      '#title'         => $this->t('Header Styles'),
+      '#default_value' => isset($header_section['styles']) ? $header_section['styles'] : '',
+      '#description'   => $this->t('<p>You can add multiple <strong>stylesheets</strong> here with multiple ways, For example: </p><p>1. &lt;link type="text/css" rel="stylesheet" href="http://www.example.com/style.css" media="all" /&gt;</p><p> 2. &lt;link type="text/css" rel="stylesheet" href="/style.css" media="all" /&gt;</p><p> 3. &lt;style&gt;#header { color: grey; }&lt;/style&gt;</p>'),
+      '#rows'          => 10,
+    ];
+
+    $form['hfs_header']['scripts'] = [
+      '#type'          => 'textarea',
+      '#title'         => $this->t('Header Scripts'),
+      '#default_value' => isset($header_section['scripts']) ? $header_section['scripts'] : '',
+      '#description'   => $this->t('<p>You can add multiple <strong>scripts</strong> here with multiple ways, For example: </p><p>1. &lt;script type="text/javascript" src="http://www.example.com/script.js"&gt;&lt;/script&gt;</p><p> 2. &lt;script type="text/javascript" src="/script.js"&gt;&lt;/script&gt;</p><p> 3. &lt;script type="text/javascript"&gt;console.log("HFS Header");&lt;/script&gt;</p>'),
+      '#rows'          => 10,
+    ];
+
+    return parent::buildForm($form, $form_state);
+  }
+
+  /**
+   * Implements FormBuilder::submitForm().
+   *
+   * Serialize the user's settings and save it to the Drupal's config Table.
+   */
+  public function submitForm(array &$form, FormStateInterface $form_state) {
+    $values = $form_state->getValues();
+
+    $this->configFactory()
+      ->getEditable('hfs_header_scripts.settings')
+      ->set('styles', $values['styles'])
+      ->set('scripts', $values['scripts'])
+      ->save();
+
+    drupal_set_message($this->t('Your Settings have been saved.'), 'status');
+  }
+
+}