Support hook_block_build_alter() and hook_block_view_alter()

Uploaded patch:

• invoked alter hook for block_build
• added __construct() and create() to inject dependencies (added the module handler)

Next step: invoke alter hook for block_view

When we were looking at this, I was kind of wondering if there shouldn't actually be more code in the base class than there is right now?

Fixed failing tests by PHPUnit tests.

After an attentive check with @Berdir, the alter hook added in the previous patch should be related to block_view instead of block_build. Fixed that.
Also we need some more discussion about what we should do with that base class.

Created followup for block_build and for the discussion about the base class.

This needs tests. Also $moduleHandler should be $module_handler.

Replaced $moduleHandler with $module_handler and provided a test for this alter hook.

1. +++ b/src/Plugin/DisplayVariant/PageBlockDisplayVariant.php
   @@ -26,6 +32,55 @@ use Drupal\ctools\Plugin\DisplayVariant\BlockDisplayVariant;
   +  protected $module_handler;
   

   Sorry. I only meant change the standalone variable, not the property. Should be $this->moduleHandler, and $module_handler.

2. +++ b/src/Tests/PageManagerAdminTest.php
   @@ -265,6 +265,32 @@ class PageManagerAdminTest extends WebTestBase {
   +  protected function doTestAlterBlock() {
   

   This method won't run unless you call it from testAdmin(). Or just make it public function testAlterBlock()

• fixed property $moduleHandler
• fixed doTestAlterBlock(), added it in testAdmin() (consistency)
• fixed failing test in doTestEditVariant()

1. +++ b/src/Plugin/DisplayVariant/PageBlockDisplayVariant.php
   @@ -93,6 +148,8 @@ class PageBlockDisplayVariant extends BlockDisplayVariant {
   +        // Allow altering of cacheability metadata or setting #create_placeholder.
   +        $this->moduleHanlder->alter(['block_view', "block_view_" . $block->getBaseId()], $block_build, $block);
   

   I think the comment here is now wrong (copied from the build hook), use the comment from the view hook instead.

2. +++ b/src/Tests/PageManagerAdminTest.php
   @@ -265,6 +266,37 @@ class PageManagerAdminTest extends WebTestBase {
   +    $edit = [
   +      'settings[label]' => 'Altered block label',
   

   Hm. Lets use something like "Label to be altered" or something like that. Altered label is not correct since it is not (yet) altered.

3. +++ b/src/Tests/PageManagerAdminTest.php
   @@ -265,6 +266,37 @@ class PageManagerAdminTest extends WebTestBase {
   +    // Check the altered block label.
   +    $this->assertRaw($edit['settings[label]']);
   

   Because we do *not* want to see this label. You're missing the crucial part of the test, to actually implement the alter hook and switch it to something else.

   The idea is that you set the label to what I said above, and then the alter hook changes it to "Altered label"

4. +++ b/src/Tests/PageManagerAdminTest.php
   @@ -278,8 +310,8 @@ class PageManagerAdminTest extends WebTestBase {
    
   -    $this->assertOptionSelected('edit-variant-plugin-blocks-' . $block_config['uuid'] . '-region', 'top');
   -    $this->assertOptionSelected('edit-variant-plugin-blocks-' . $block_config['uuid'] . '-weight', 0);
   +    $this->assertOptionSelected('edit-variant-plugin-blocks-' . strtolower($block_config['uuid']) . '-region', 'top');
   +    $this->assertOptionSelected('edit-variant-plugin-blocks-' . strtolower($block_config['uuid']) . '-weight', 0);
    
   

   This is a weird php/osx bug. Remove the uuid extension locally, it incorrectly generates uppercase UUID's.

• fixed 1-4
• added the help module page_manager_test.module for the page_manager test

This looks good to me. We also tested it manually and it allows to use tokens in block titles and they are then replaced by token.module.

1. +++ b/src/Plugin/DisplayVariant/PageBlockDisplayVariant.php
   @@ -26,6 +32,55 @@ use Drupal\ctools\Plugin\DisplayVariant\BlockDisplayVariant;
   +  protected $moduleHanlder;
   

   Hanlder is spelled wrong

2. +++ b/src/Plugin/DisplayVariant/PageBlockDisplayVariant.php
   @@ -26,6 +32,55 @@ use Drupal\ctools\Plugin\DisplayVariant\BlockDisplayVariant;
   +  public function __construct(array $configuration, $plugin_id, $plugin_definition, ContextHandlerInterface $context_handler, AccountInterface $account, UuidInterface $uuid_generator, Token $token, ModuleHandlerInterface $module_handler) {
   

   The upstream signature changed, this needs a reroll.

Rerolled and refactored the typo.

Reroll looks good to me, typo fixed.

Committed