Basic Extension Dependency Support

js/src/admin/components/ExtensionsPage.js

@@ -123,6 +123,7 @@ export default class ExtensionsPage extends Page {
         url: app.forum.attribute('apiUrl') + '/extensions/' + id,
         method: 'PATCH',
         body: { enabled: !enabled },
+        errorHandler: this.onerror.bind(this),
       })
       .then(() => {
         if (!enabled) localStorage.setItem('enabledExtension', id);
@@ -131,4 +132,18 @@ export default class ExtensionsPage extends Page {
 
     app.modal.show(LoadingModal);
   }
+
+  onerror(e) {
+    app.modal.close();
+
+    const error = JSON.parse(e.responseText).errors[0];
+
+    app.alerts.show(
+      { type: 'error' },
+      app.translator.trans(`core.lib.error.${error.code}_message`, {
+        extension: error.extension,
+        extensions: error.extensions.join(', '),
+      })
+    );
+  }
 }

src/Extension/Exception/DependentExtensionsException.php

@@ -0,0 +1,31 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Extension\Exception;
+
+use Exception;
+use Flarum\Extension\Extension;
+
+class DependentExtensionsException extends Exception
+{
+    public $extension;
+    public $dependent_extensions;
+
+    /**
+     * @param $extension: The extension we are attempting to activate.
+     * @param $dependent_extensions: Extension IDs of the Flarum extensions that depend on this extension
+     */
+    public function __construct(Extension $extension, array $dependent_extensions)
+    {
+        $this->extension = $extension;
+        $this->dependent_extensions = $dependent_extensions;
+
+        parent::__construct(implode("\n", $dependent_extensions));
+    }
+}

src/Extension/Exception/DependentExtensionsExceptionHandler.php

@@ -0,0 +1,34 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Extension\Exception;
+
+use Flarum\Foundation\ErrorHandling\HandledError;
+
+class DependentExtensionsExceptionHandler
+{
+    public function handle(DependentExtensionsException $e): HandledError
+    {
+        return (new HandledError(
+            $e,
+            'dependent_extensions',
+            409
+        ))->withDetails($this->errorDetails($e));
+    }
+
+    protected function errorDetails(DependentExtensionsException $e): array
+    {
+        return [
+            [
+                'extension' => $e->extension->getId(),
+                'extensions' => $e->dependent_extensions
+            ]
+        ];
+    }
+}

src/Extension/Exception/MissingDependenciesException.php

@@ -0,0 +1,31 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Extension\Exception;
+
+use Exception;
+use Flarum\Extension\Extension;
+
+class MissingDependenciesException extends Exception
+{
+    public $extension;
+    public $missing_dependencies;
+
+    /**
+     * @param $extension: The extension we are attempting to activate.
+     * @param $missing_dependencies: Extension IDs of the missing flarum extension dependencies for this extension
+     */
+    public function __construct(Extension $extension, array $missing_dependencies = null)
+    {
+        $this->extension = $extension;
+        $this->missing_dependencies = $missing_dependencies;
+
+        parent::__construct(implode("\n", $missing_dependencies));
+    }
+}

src/Extension/Exception/MissingDependenciesExceptionHandler.php

@@ -0,0 +1,34 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Extension\Exception;
+
+use Flarum\Foundation\ErrorHandling\HandledError;
+
+class MissingDependenciesExceptionHandler
+{
+    public function handle(MissingDependenciesException $e): HandledError
+    {
+        return (new HandledError(
+            $e,
+            'missing_dependencies',
+            409
+        ))->withDetails($this->errorDetails($e));
+    }
+
+    protected function errorDetails(MissingDependenciesException $e): array
+    {
+        return [
+            [
+                'extension' => $e->extension->getId(),
+                'extensions' => $e->missing_dependencies
+            ]
+        ];
+    }
+}

src/Extension/Extension.php

@@ -15,6 +15,7 @@
 use Illuminate\Contracts\Container\Container;
 use Illuminate\Contracts\Support\Arrayable;
 use Illuminate\Support\Arr;
+use Illuminate\Support\Collection;
 use Illuminate\Support\Str;
 use League\Flysystem\Adapter\Local;
 use League\Flysystem\Filesystem;
@@ -51,6 +52,14 @@ class Extension implements Arrayable
         'jpg' => 'image/jpeg',
     ];
 
+    protected static function nameToId($name)
+    {
+        list($vendor, $package) = explode('/', $name);
+        $package = str_replace(['flarum-ext-', 'flarum-'], '', $package);
+
+        return "$vendor-$package";
+    }
+
     /**
      * Unique Id of the extension.
      *
@@ -74,6 +83,13 @@ class Extension implements Arrayable
      */
     protected $composerJson;
 
+    /**
+     * An array of extension ids for extension dependencies.
+     *
+     * @var string[]
+     */
+    protected $dependencies;
+
     /**
      * Whether the extension is installed.
      *
@@ -104,9 +120,7 @@ public function __construct($path, $composerJson)
      */
     protected function assignId()
     {
-        list($vendor, $package) = explode('/', $this->name);
-        $package = str_replace(['flarum-ext-', 'flarum-'], '', $package);
-        $this->id = "$vendor-$package";
+        $this->id = static::nameToId($this->name);
     }
 
     public function extend(Container $app)
@@ -182,6 +196,22 @@ public function setVersion($version)
         return $this;
     }
 
+    /**
+     * Get the list of flarum extensions that this extension depends on.
+     *
+     * @param array $lockJson: The json manifest of all installed php extensions
+     */
+    public function calculateDependencies($lockJson)
+    {
+        $this->extensionDependencies = (new Collection(Arr::get($this->composerJson, 'require', [])))
+            ->keys()
+            ->filter(function ($key) use ($lockJson) {
+                return array_key_exists($key, $lockJson);
+            })->map(function ($key) {
+                return static::nameToId($key);
+            })->toArray();
+    }
+
     /**
      * @return string
      */
@@ -363,12 +393,13 @@ public function migrate(Migrator $migrator, $direction = 'up')
     public function toArray()
     {
         return (array) array_merge([
-            'id'            => $this->getId(),
-            'version'       => $this->getVersion(),
-            'path'          => $this->path,
-            'icon'          => $this->getIcon(),
-            'hasAssets'     => $this->hasAssets(),
-            'hasMigrations' => $this->hasMigrations(),
+            'id'                    => $this->getId(),
+            'version'               => $this->getVersion(),
+            'path'                  => $this->path,
+            'icon'                  => $this->getIcon(),
+            'hasAssets'             => $this->hasAssets(),
+            'hasMigrations'         => $this->hasMigrations(),
+            'extensionDependencies' => $this->extensionDependencies,
         ], $this->composerJson);
     }
 }

src/Extension/ExtensionManager.php

@@ -83,11 +83,21 @@ public function getExtensions()
             // Composer 2.0 changes the structure of the installed.json manifest
             $installed = $installed['packages'] ?? $installed;
 
+            // We calculate and store a set of installed extension IDs (associative array with true keys)
+            // to speed up figuring what is and isn't a flarum extension later on.
+            // By only including flarum extensions, we know that anything present in this associative copy
+            // is a flarum extension, removing the need to check for it's type.
+            // We store the installed flarum extensions as keys, not values, of this array
+            // so that we have constant lookup time.
+            $installedSet = [];
+
             foreach ($installed as $package) {
                 if (Arr::get($package, 'type') != 'flarum-extension' || empty(Arr::get($package, 'name'))) {
                     continue;
                 }
 
+                $installedSet[Arr::get($package, 'name')] = true;
+
                 $path = isset($package['install-path'])
                     ? $this->paths->vendor.'/composer/'.$package['install-path']
                     : $this->paths->vendor.'/'.Arr::get($package, 'name');
@@ -101,6 +111,13 @@ public function getExtensions()
 
                 $extensions->put($extension->getId(), $extension);
             }
+
+            $installedSet = $extensions->pluck('name')->toArray();
+
+            foreach ($extensions as $extension) {
+                $extension->calculateDependencies($installedSet);
+            }
+
             $this->extensions = $extensions->sortBy(function ($extension, $name) {
                 return $extension->composerJsonAttribute('extra.flarum-extension.title');
             });
@@ -133,6 +150,18 @@ public function enable($name)
 
         $extension = $this->getExtension($name);
 
+        $missingDependencies = [];
+        $enabled = $this->getEnabled();
+        foreach ($extension->extensionDependencies as $dependency) {
+            if (! in_array($dependency, $enabled)) {
+                $missingDependencies[] = $dependency;
+            }
+        }
+
+        if (! empty($missingDependencies)) {
+            throw new Exception\MissingDependenciesException($extension, $missingDependencies);
+        }
+
         $this->dispatcher->dispatch(new Enabling($extension));
 
         $enabled = $this->getEnabled();
@@ -165,6 +194,23 @@ public function disable($name)
 
         $extension = $this->getExtension($name);
 
+        $dependentExtensions = [];
+
+        foreach ($this->getEnabledExtensions() as $possibleDependent) {
+            foreach ($possibleDependent->extensionDependencies as $dependency) {
+                // We check all enabled extensions. For each of them, if any depend on the extension
+                // we're disabling, we add it to the list and move onto the next one.
+                if ($dependency === $extension->getId()) {
+                    $dependentExtensions[] = $possibleDependent->getId();
+                    break;
+                }
+            }
+        }
+
+        if (! empty($dependentExtensions)) {
+            throw new Exception\DependentExtensionsException($extension, $dependentExtensions);
+        }
+
         $this->dispatcher->dispatch(new Disabling($extension));
 
         unset($enabled[$k]);

src/Foundation/ErrorServiceProvider.php

@@ -9,6 +9,10 @@
 
 namespace Flarum\Foundation;
 
+use Flarum\Extension\Exception\DependentExtensionsException;
+use Flarum\Extension\Exception\DependentExtensionsExceptionHandler;
+use Flarum\Extension\Exception\MissingDependenciesException;
+use Flarum\Extension\Exception\MissingDependenciesExceptionHandler;
 use Flarum\Foundation\ErrorHandling\ExceptionHandler;
 use Flarum\Foundation\ErrorHandling\LogReporter;
 use Flarum\Foundation\ErrorHandling\Registry;
@@ -57,6 +61,8 @@ public function register()
             return [
                 IlluminateValidationException::class => ExceptionHandler\IlluminateValidationExceptionHandler::class,
                 ValidationException::class => ExceptionHandler\ValidationExceptionHandler::class,
+                DependentExtensionsException::class => DependentExtensionsExceptionHandler::class,
+                MissingDependenciesException::class => MissingDependenciesExceptionHandler::class,
             ];
         });