Issue #2482215 by alexpott: Improve config_prefix documentation

core/lib/Drupal/Core/Config/Entity/ConfigEntityType.php

@@ -20,12 +20,7 @@ class ConfigEntityType extends EntityType implements ConfigEntityTypeInterface {
   /**
    * The config prefix set in the configuration entity type annotation.
    *
-   * The default configuration prefix is constructed from the name of the module
-   * that provides the entity type and the ID of the entity type. If a
-   * config_prefix annotation is present it will be used in place of the entity
-   * type ID.
-   *
-   * @see \Drupal\Core\Config\Entity\ConfigEntityType::getConfigPrefix()
+   * @see \Drupal\Core\Config\Entity\ConfigEntityTypeInterface::getConfigPrefix()
    */
   protected $config_prefix;
 
@@ -89,10 +84,7 @@ class ConfigEntityType extends EntityType implements ConfigEntityTypeInterface {
    */
   public function getConfigPrefix() {
     // Ensure that all configuration entities are prefixed by the name of the
-    // module that provides the configuration entity type. This ensures that
-    // default configuration will be created as expected during module
-    // installation and dependencies can be calculated without the modules that
-    // provide the entity types being installed.
+    // module that provides the configuration entity type.
     if (isset($this->config_prefix)) {
       $config_prefix = $this->provider . '.' . $this->config_prefix;
     }

core/lib/Drupal/Core/Config/Entity/ConfigEntityTypeInterface.php

@@ -49,15 +49,21 @@ interface ConfigEntityTypeInterface extends EntityTypeInterface {
   /**
    * Gets the config prefix used by the configuration entity type.
    *
-   * Ensures that all configuration entities are prefixed by the module that
-   * provides the configuration entity type. This ensures that if a
-   * configuration entity is contained in a extension's default configuration,
-   * it will be created during extension installation. Additionally, it allows
-   * dependencies to be calculated without the modules that provide
-   * configuration entity types being installed.
+   * The config prefix is used to prefix configuration entity IDs when they are
+   * stored in the configuration system. The default config prefix is
+   * constructed from the name of the module that provides the entity type and
+   * the ID of the entity type. If a config_prefix annotation is present it will
+   * be used in place of the entity type ID.
    *
-   * @return string|bool
-   *   The config prefix, or FALSE if not a configuration entity type.
+   * Prefixing with the module that provides the configuration entity type
+   * ensures that configuration entities depend on the module that provides the
+   * configuration entity type.
+   *
+   * @return string
+   *   The config prefix.
+   *
+   * @throws \Drupal\Core\Config\ConfigPrefixLengthException
+   *   Exception thrown when the length of the prefix exceeds PREFIX_LENGTH.
    */
   public function getConfigPrefix();