Adding a config entity for the module to save site info.

config/schema/sitedash.schema.yml

@@ -0,0 +1,20 @@
+sitedash.sitedash.*:
+  type: config_entity
+  label: 'Sitedash config'
+  mapping:
+    id:
+      type: string
+      label: 'ID'
+    label:
+      type: label
+      label: 'Label'
+    siteUrl:
+      type: string
+      label: 'Sitedash Site URL'
+    siteAPIUrl:
+      type: string
+      label: 'Sitedash Site API endpoint URL'
+    token:
+      type: string
+      label: 'Sitedash Site API token'
+

sitedash.links.action.yml

@@ -0,0 +1,5 @@
+entity.sitedash.add_form:
+  route_name: 'entity.sitedash.add_form'
+  title: 'Add sitedash'
+  appears_on:
+    - entity.sitedash.collection

sitedash.links.menu.yml

@@ -0,0 +1,5 @@
+entity.sitedash.collection:
+  title: 'Sitedash'
+  parent: system.admin_config_system
+  description: 'Configure sitedash'
+  route_name: entity.sitedash.collection

sitedash.routing.yml

@@ -4,4 +4,36 @@ sitedash.content:
     _controller: '\Drupal\sitedash\Controller\SiteDashController::content'
     _title: 'Site Dashboard'
   requirements:
-    _permission: 'access content'
+    _permission: 'administer site configuration'
+
+entity.sitedash.collection:
+  path: '/admin/config/system/sitedash'
+  defaults:
+    _entity_list: 'sitedash'
+    _title: 'Sitedash configuration'
+  requirements:
+    _permission: 'administer site configuration'
+
+entity.sitedash.add_form:
+  path: '/admin/config/system/sitedash/add'
+  defaults:
+    _entity_form: 'sitedash.add'
+    _title: 'Add sitedash'
+  requirements:
+    _permission: 'administer site configuration'
+
+entity.sitedash.edit_form:
+  path: '/admin/config/system/sitedash/{sitedash}'
+  defaults:
+    _entity_form: 'sitedash.edit'
+    _title: 'Edit sitedash'
+  requirements:
+    _permission: 'administer site configuration'
+
+entity.sitedash.delete_form:
+  path: '/admin/config/system/sitedash/{sitedash}/delete'
+  defaults:
+    _entity_form: 'sitedash.delete'
+    _title: 'Delete sitedash'
+  requirements:
+    _permission: 'administer site configuration'

src/Controller/SitedashListBuilder.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace Drupal\sitedash\Controller;
+
+use Drupal\Core\Config\Entity\ConfigEntityListBuilder;
+use Drupal\Core\Entity\EntityInterface;
+
+/**
+ * Provides a listing of Sitedash.
+ */
+class SitedashListBuilder extends ConfigEntityListBuilder {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildHeader() {
+    $header['label'] = $this->t('Sitedash');
+    $header['id'] = $this->t('Machine name');
+    $header['siteUrl'] = $this->t('Site URL');
+    return $header + parent::buildHeader();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildRow(EntityInterface $entity) {
+    $row['label'] = $entity->label();
+    $row['id'] = $entity->id();
+    $row['siteUrl'] = $entity->siteUrl;
+
+    // You probably want a few more properties here...
+
+    return $row + parent::buildRow($entity);
+  }
+
+}

src/Entity/Sitedash.php

@@ -0,0 +1,101 @@
+<?php
+
+namespace Drupal\sitedash\Entity;
+
+use Drupal\Core\Config\Entity\ConfigEntityBase;
+use Drupal\sitedash\SitedashInterface;
+
+/**
+ * Defines the Sitedash entity.
+ *
+ * @ConfigEntityType(
+ *   id = "sitedash",
+ *   label = @Translation("Sitedash"),
+ *   handlers = {
+ *     "list_builder" = "Drupal\sitedash\Controller\SitedashListBuilder",
+ *     "form" = {
+ *       "add" = "Drupal\sitedash\Form\SitedashForm",
+ *       "edit" = "Drupal\sitedash\Form\SitedashForm",
+ *       "delete" = "Drupal\sitedash\Form\SitedashDeleteForm",
+ *     }
+ *   },
+ *   config_prefix = "sitedash",
+ *   admin_permission = "administer site configuration",
+ *   entity_keys = {
+ *     "id" = "id",
+ *     "label" = "label",
+ *   },
+ *   config_export = {
+ *     "id",
+ *     "label",
+ *     "siteUrl",
+ *     "siteAPIUrl",
+ *     "token"
+ *   },
+ *   links = {
+ *     "edit-form" = "/admin/config/system/sitedash/{sitedash}",
+ *     "delete-form" = "/admin/config/system/sitedash/{sitedash}/delete",
+ *   }
+ * )
+ */
+class Sitedash extends ConfigEntityBase implements SitedashInterface {
+
+  /**
+   * The Sitedash ID.
+   *
+   * @var string
+   */
+  protected $id;
+
+  /**
+   * The Sitedash label.
+   *
+   * @var string
+   */
+  protected $label;
+
+  /**
+   * The Sitedash Site URL.
+   *
+   * @var string
+   */
+  public $siteUrl;
+
+  /**
+   * The Sitedash Site API Endpoint URL.
+   *
+   * @var string
+   */
+  public $siteAPIUrl;
+
+  /**
+   * The Sitedash Site API token.
+   *
+   * @var string
+   */
+  public $token;
+
+  // Your specific configuration property get/set methods go here,
+  // implementing the interface.
+  /**
+   * {@inheritdoc}
+   */
+  public function getSiteUrl() {
+    return $this->siteUrl;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getSiteAPIUrl() {
+    return $this->siteAPIUrl;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getToken() {
+    return $this->token;
+  }
+
+}

src/Form/SitedashDeleteForm.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace Drupal\sitedash\Form;
+
+use Drupal\Core\Entity\EntityConfirmFormBase;
+use Drupal\Core\Url;
+use Drupal\Core\Form\FormStateInterface;
+
+/**
+ * Builds the form to delete an Example.
+ */
+
+class SitedashDeleteForm extends EntityConfirmFormBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getQuestion() {
+    return $this->t('Are you sure you want to delete %name?', ['%name' => $this->entity->label()]);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getCancelUrl() {
+    return new Url('entity.sitedash.collection');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getConfirmText() {
+    return $this->t('Delete');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function submitForm(array &$form, FormStateInterface $form_state) {
+    $this->entity->delete();
+    $this->messenger()->addMessage($this->t('Entity %label has been deleted.', ['%label' => $this->entity->label()]));
+
+    $form_state->setRedirectUrl($this->getCancelUrl());
+  }
+
+}

src/Form/SitedashForm.php

@@ -0,0 +1,123 @@
+<?php
+
+namespace Drupal\sitedash\Form;
+
+use Drupal\Core\Entity\EntityForm;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Form handler for the Sitedash add and edit forms.
+ */
+class SitedashForm extends EntityForm {
+
+  /**
+   * Constructs an SitedashForm object.
+   *
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entityTypeManager
+   *   The entityTypeManager.
+   */
+  public function __construct(EntityTypeManagerInterface $entityTypeManager) {
+    $this->entityTypeManager = $entityTypeManager;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get('entity_type.manager')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function form(array $form, FormStateInterface $form_state) {
+    $form = parent::form($form, $form_state);
+
+    $sitedash = $this->entity;
+
+    // Change page title for the edit operation.
+    if ($this->operation == 'edit') {
+      $form['#title'] = $this->t('Edit sitedash: @label', ['@label' => $sitedash->label()]);
+    }
+
+    $form['label'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Site Name'),
+      '#maxlength' => 255,
+      '#default_value' => $sitedash->label(),
+      '#description' => $this->t("Label for the Sitedash Site."),
+      '#required' => TRUE,
+    ];
+    $form['id'] = [
+      '#type' => 'machine_name',
+      '#default_value' => $sitedash->id(),
+      '#machine_name' => [
+        'exists' => [$this, 'exist'],
+      ],
+      '#disabled' => !$sitedash->isNew(),
+    ];
+    $form['siteUrl'] = [
+      '#type' => 'url',
+      '#title' => $this->t('Site URL'),
+      '#size' => 50,
+      '#default_value' => $sitedash->getSiteUrl(),
+      '#description' => $this->t("The Site URL."),
+      '#required' => TRUE,
+    ];
+    $form['siteAPIUrl'] = [
+      '#type' => 'url',
+      '#title' => $this->t('Site API end point URL'),
+      '#size' => 100,
+      '#default_value' => $sitedash->getSiteAPIUrl(),
+      '#description' => $this->t("API endpoint of the connector site."),
+      '#required' => TRUE,
+    ];
+    $form['token'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('API Token'),
+      '#maxlength' => 255,
+      '#default_value' => $sitedash->getToken(),
+      '#description' => $this->t("API token for the site."),
+      '#required' => TRUE,
+    ];
+
+    // You will need additional form elements for your custom properties.
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function save(array $form, FormStateInterface $form_state) {
+    $sitedash = $this->entity;
+    $status = $sitedash->save();
+
+    if ($status === SAVED_NEW) {
+      $this->messenger()->addMessage($this->t('The %label Sitedash Site created.', [
+        '%label' => $sitedash->label(),
+      ]));
+    }
+    else {
+      $this->messenger()->addMessage($this->t('The %label Sitedash Site updated.', [
+        '%label' => $sitedash->label(),
+      ]));
+    }
+
+    $form_state->setRedirect('entity.sitedash.collection');
+  }
+
+  /**
+   * Helper function to check whether an Sitedash configuration entity exists.
+   */
+  public function exist($id) {
+    $entity = $this->entityTypeManager->getStorage('sitedash')->getQuery()
+      ->condition('id', $id)
+      ->execute();
+    return (bool) $entity;
+  }
+
+}

src/SitedashInterface.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace Drupal\sitedash;
+
+use Drupal\Core\Config\Entity\ConfigEntityInterface;
+
+/**
+ * Provides an interface defining an Example entity.
+ */
+interface SitedashInterface extends ConfigEntityInterface {
+// Add get/set methods for your configuration properties here.
+  public function getSiteUrl();
+  public function getToken();
+  public function getSiteAPIUrl();
+}