hook_block_alter documentation missing

Well, that's very interesting. I see two implementations in core -- one in a test, and one in statistics.module. But I don't see where this hook is invoked. Any ideas?

According to Berdir's StackOverflow answer, it is called in \Drupal\Core\Block\BlockManager

What is a proper place to put this hooks?

Example of usage

/**
 * Implements hook_block_alter().
 */
function example_module_block_alter(&$definitions) {
  foreach ($definitions as $id => $definition) {
    if (strpos($id, 'system_menu_block:') === 0) {
      // Replace $definition properties: id, deriver, class, provider to ones
      // provided by this custom module.
    }
  }
}

I think for blocks it makes sense to have separate *.api.php like menu has core/lib/Drupal/Core/Menu/menu.api.php

Here is the patch.

+++ b/core/modules/block/block.api.php
@@ -216,6 +216,22 @@ function hook_block_access(\Drupal\block\Entity\Block $block, $operation, \Drupa
+ * @param $definitions
+ *   The array of block definitions, keyed by plugin ID.

Definitions should be typed, I bet it kinda \Drupal\Component\Plugin\Definition\PluginDefinitionInterface[]|array[] as \Drupal\Core\Plugin\FilteredPluginManagerInterface::getFilteredDefinitions() returns

@ashrafabed Now @param line length is going more than 80 characters. Is it allowed to go more than 80 characters if we specify FQN of the types of param?

Tested #14, hook_block_alter code has been added

Applied patch #14 and it works . The hook_block_alter is correctly documented in the patch

+++ b/core/modules/block/block.api.php
@@ -216,6 +216,22 @@ function hook_block_access(\Drupal\block\Entity\Block $block, $operation, \Drupa
+ * @param \Drupal\Component\Plugin\Definition\PluginDefinitionInterface[]|array[] $definitions

We know that blocks are not going to be \Drupal\Component\Plugin\Definition\PluginDefinitionInterface[] so only array[] is needed here.

@alexpott removed PluginDefinitionInterface[], needs review.

Hello,

As the patch in #23 failed to apply and found to be not a proper patch. I've created a new patch addressing the comment #22.

Please review.

Patch looks good to me.

Committed/pushed to 9.2.x and cherry-picked to 9.1.x, thanks!