NEW LinkableMigrationTask for migrating sheadawson-lin kable links

docs/en/09_migrating/02_gorriecoe-migration.md

@@ -54,6 +54,9 @@ composer require silverstripe/linkfield:^4
 
 ### Configure the migration task
 
+> [!NOTE]
+> Be sure to check how the old module classes are referenced in config `yml` files (eg: `app/_config`). Update appropriately.
+
 1. Enable the task:
 
     ```yml
@@ -122,6 +125,8 @@ composer require silverstripe/linkfield:^4
 
 ### Update your codebase
 
+You should review how you are using the original `Link` model and `LinkField`, but if you don't have any customisations, then replacing the old with the new might be quite simple.
+
 1. If you added any database columns to the `Link` class for sorting `has_many` relations, or any `has_one` relations for storing them, remove the extension or YAML configuration for that now.
 
     ```diff
@@ -277,8 +282,8 @@ For databases that support transactions, the full data migration is performed wi
     - via the browser: `https://www.example.com/dev/build?flush=1`
     - via a terminal: `sake dev/build flush=1`
 1. Run the task
-    - via the browser: `https://www.example.com/dev/tasks/linkfield-tov4-migration-task`
-    - via a terminal: `sake dev/tasks/linkfield-tov4-migration-task`
+    - via the browser: `https://www.example.com/dev/tasks/gorriecoe-to-linkfield-migration-task`
+    - via a terminal: `sake dev/tasks/gorriecoe-to-linkfield-migration-task`
 
 The task performs the following steps:
 

src/Tasks/LinkFieldMigrationTask.php

@@ -278,9 +278,4 @@ private function migrateHasManyRelations(): void
         }
         $this->extend('afterMigrateHasManyRelations');
     }
-
-    private function classIsOldLink(string $class): bool
-    {
-        return is_a($class, Link::class, true);
-    }
 }

src/Tasks/LinkableMigrationTask.php

@@ -0,0 +1,129 @@
+<?php declare(strict_types=1);
+
+namespace SilverStripe\LinkField\Tasks;
+
+use RuntimeException;
+use SilverStripe\Dev\BuildTask;
+use SilverStripe\LinkField\Models\Link;
+use SilverStripe\LinkField\Models\EmailLink;
+use SilverStripe\LinkField\Models\ExternalLink;
+use SilverStripe\LinkField\Models\FileLink;
+use SilverStripe\LinkField\Models\PhoneLink;
+use SilverStripe\LinkField\Models\SiteTreeLink;
+use SilverStripe\ORM\DB;
+
+/**
+ * @deprecated 4.0.0 Will be removed without equivalent functionality.
+ */
+class LinkableMigrationTask extends BuildTask
+{
+    use MigrationTaskTrait;
+    use ModuleMigrationTaskTrait;
+
+    private static $segment = 'linkable-to-linkfield-migration-task';
+
+    protected $title = 'Linkable to Linkfield Migration Task';
+
+    protected $description = 'Migrate from sheadawson/silverstripe-linkable to silverstripe/linkfield';
+
+    /**
+     * Enable via YAML configuration if you need to run this task
+     */
+    private static ?bool $is_enabled = false;
+
+    /**
+     * The number of links to process at once, for operations that operate on each link individually.
+     * Processing links in chunks reduces the chance of hitting memory limits.
+     * Set to null to process all links in a single chunk.
+     */
+    private static ?int $chunk_size = 1000;
+
+    /**
+     * The name of the table for the Sheadawson\Linkable\Models\Link model.
+     *
+     * Configurable since it's such a generic name, there's a chance people configured
+     * it to something different to avoid collisions.
+     */
+    private static string $old_link_table = 'LinkableLink';
+
+    /**
+     * Mapping for columns in the base link table.
+     * Doesn't include subclass columns - see link_type_columns
+     */
+    private static array $base_link_columns = [
+        'OpenInNewWindow' => 'OpenInNew',
+        'Title' => 'LinkText',
+    ];
+
+    /**
+     * Mapping for different types of links, including the class to map to and
+     * database column mappings.
+     */
+    private static array $link_type_columns = [
+        'URL' => [
+            'class' => ExternalLink::class,
+            'fields' => [
+                'URL' => 'ExternalUrl',
+            ],
+        ],
+        'Email' => [
+            'class' => EmailLink::class,
+            'fields' => [
+                'Email' => 'Email',
+            ],
+        ],
+        'Phone' => [
+            'class' => PhoneLink::class,
+            'fields' => [
+                'Phone' => 'Phone',
+            ],
+        ],
+        'File' => [
+            'class' => FileLink::class,
+            'fields' => [
+                'FileID' => 'FileID',
+            ],
+        ],
+        'SiteTree' => [
+            'class' => SiteTreeLink::class,
+            'fields' => [
+                'SiteTreeID' => 'PageID',
+            ],
+        ],
+    ];
+
+    /**
+     * Perform the actual data migration and publish links as appropriate
+     */
+    public function performMigration(): void
+    {
+        $this->extend('beforePerformMigration');
+        // Because we're using SQL INSERT with specific ID values,
+        // we can't perform the migration if there are existing links because there
+        // may be ID conflicts.
+        if (Link::get()->exists()) {
+            throw new RuntimeException('Cannot perform migration with existing silverstripe/linkfield link records.');
+        }
+
+        $this->insertBaseRows();
+        $this->insertTypeSpecificRows();
+        $this->updateSiteTreeRows();
+        $this->migrateHasManyRelations();
+        $this->migrateManyManyRelations();
+        $this->setOwnerForHasOneLinks();
+
+        $this->print("Dropping old link table '{$this->oldTableName}'");
+        DB::get_conn()->query("DROP TABLE \"{$this->oldTableName}\"");
+
+        $this->print('-----------------');
+        $this->print('Bulk data migration complete. All links should be correct (but unpublished) at this stage.');
+        $this->print('-----------------');
+
+        $this->publishLinks();
+
+        $this->print('-----------------');
+        $this->print('Migration completed successfully.');
+        $this->print('-----------------');
+        $this->extend('afterPerformMigration');
+    }
+}

src/Tasks/MigrationTaskTrait.php

@@ -126,7 +126,7 @@ private function setOwnerForHasOneLinks(): void
                 }
 
                 // Skip if the has_one isn't for Link, or points at a belongs_to or has_many on Link
-                if (!$this->classIsOldLink($hasOneClass)) {
+                if (!is_a($hasOneClass, Link::class, true)) {
                     continue;
                 }
                 if ($this->hasReciprocalRelation([$hasOneClass], $hasOneName, $modelClass)) {
@@ -435,9 +435,4 @@ abstract public function performMigration(): void;
      * Check if we actually need to migrate anything, and if not give clear output as to why not.
      */
     abstract private function getNeedsMigration(): bool;
-
-    /**
-     * Returns true if the class represents an old link to be migrated
-     */
-    abstract private function classIsOldLink(string $class): bool;
 }