From a85bd3d213aa6abe53d19d354f146652bfba1c5a Mon Sep 17 00:00:00 2001
From: William Hearn <sylus1984@gmail.com>
Date: Thu, 2 Nov 2017 17:08:25 -0400
Subject: [PATCH] Issue #2920637: Add TaxonomyRouteContext similar to
 NodeRouteContext

---
 .../src/ContextProvider/TaxonomyRouteContext.php   | 74 ++++++++++++++++++++++
 core/modules/taxonomy/taxonomy.services.yml        |  5 ++
 2 files changed, 79 insertions(+)
 create mode 100644 core/modules/taxonomy/src/ContextProvider/TaxonomyRouteContext.php

diff --git a/core/modules/taxonomy/src/ContextProvider/TaxonomyRouteContext.php b/core/modules/taxonomy/src/ContextProvider/TaxonomyRouteContext.php
new file mode 100644
index 0000000..f8c528f
--- /dev/null
+++ b/core/modules/taxonomy/src/ContextProvider/TaxonomyRouteContext.php
@@ -0,0 +1,74 @@
+<?php
+
+namespace Drupal\taxonomy\ContextProvider;
+
+use Drupal\Core\Cache\CacheableMetadata;
+use Drupal\Core\Plugin\Context\Context;
+use Drupal\Core\Plugin\Context\ContextDefinition;
+use Drupal\Core\Plugin\Context\ContextProviderInterface;
+use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\taxonomy\Entity\Term;
+use Drupal\Core\StringTranslation\StringTranslationTrait;
+
+/**
+ * Sets the current Taxonomy Term as a context on Taxonomy routes.
+ */
+class TaxonomyRouteContext implements ContextProviderInterface {
+
+  use StringTranslationTrait;
+
+  /**
+   * The route match object.
+   *
+   * @var \Drupal\Core\Routing\RouteMatchInterface
+   */
+  protected $routeMatch;
+
+  /**
+   * Constructs a new NodeRouteContext.
+   *
+   * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
+   *   The route match object.
+   */
+  public function __construct(RouteMatchInterface $route_match) {
+    $this->routeMatch = $route_match;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getRuntimeContexts(array $unqualified_context_ids) {
+    $result = [];
+    $context_definition = new ContextDefinition('entity:taxonomy_term', NULL, FALSE);
+    $value = NULL;
+
+    if (($route_object = $this->routeMatch->getRouteObject()) && ($route_contexts = $route_object->getOption('parameters')) && isset($route_contexts['taxonomy_term'])) {
+
+      if ($term = $this->routeMatch->getParameter('taxonomy_term')) {
+        $value = $term;
+      }
+    }
+    elseif ($this->routeMatch->getRouteName() == 'taxonomy_term.add') {
+      $vocab = $this->routeMatch->getParameter('vocabulary');
+      $value = Term::create(['type' => $vocab->id()]);
+    }
+
+    $cacheability = new CacheableMetadata();
+    $cacheability->setCacheContexts(['route']);
+
+    $context = new Context($context_definition, $value);
+    $context->addCacheableDependency($cacheability);
+    $result['taxonomy_term'] = $context;
+
+    return $result;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getAvailableContexts() {
+    $context = new Context(new ContextDefinition('entity:taxonomy_term', $this->t('Taxonomy Term from URL')));
+    return ['taxonomy_term' => $context];
+  }
+
+}
diff --git a/core/modules/taxonomy/taxonomy.services.yml b/core/modules/taxonomy/taxonomy.services.yml
index a8153ed..59ec64c 100644
--- a/core/modules/taxonomy/taxonomy.services.yml
+++ b/core/modules/taxonomy/taxonomy.services.yml
@@ -4,3 +4,8 @@ services:
     arguments: ['@entity.manager']
     tags:
       - { name: breadcrumb_builder, priority: 1002 }
+  taxonomy_term.taxonomy_term_route_context:
+    class: Drupal\taxonomy\ContextProvider\TaxonomyRouteContext
+    arguments: ['@current_route_match']
+    tags:
+      - { name: 'context_provider' }
-- 
2.5.4 (Apple Git-61)