README

Converts Drupal blog data into a SilverStripe blog (built with the blog module).

Imports posts and tags in standard blog structures
Imports comments with the "comments" module (optional)
Imports blog authors and comment authors into Member records (optional)
Imports tags into many-many relationships created by the "blogcategories" module (optional)
Rewrites relative images in blog post body to a custom local folder (for manual migration)
Downloads relative images and rewrites them into a provided folder (optional)
Import posts from different blogs into different "blog holders"
Based on available CSV data, no Drupal module installation or application access required
Supports incremental imports and updates
Generates Apache rewrite rules for post URLs

Caution: The module is in alpha status, and has only been tested against Drupal 5 so far. It doesn't do a full import of every data point, see known limitations below.

Setup

SilverStripe Extensions

The SilverStripe blog and comments module don't provide all the columns necessary to map the existing Drupal data, so we need to extend them by a few columns. For example, Drupal comments have a subject line. Add the following to your config (e.g. in mysite/_config/config.yml):

BlogEntry:
  extensions:
    - DrupalBlogEntryExtension
Comment:
  extensions:
    - DrupalCommentExtension
Member:
  extensions:
    - DrupalMemberExtension

This is an optional step, and you'll need to adjust templates and CMS logic to take advantage of those new columns.

SQL Export Script

The export logic is placed in tools/export.sql.

The module operates on CSV data, which can be retrieved through the MySQL commandline tool. Please note that the SQL user needs to have been granted File permissions, since the script uses SELECT ... INTO OUTFILE.

The script assumes your column type for blog nodes is called 'column'. If its called something different (e.g. 'blog'), replace the value in the SQL script. Don't forget to add any table name prefixes should you have configured them.

By default, the CSV data is exported to the /tmp folder. Change the script paths if you don't have access to this location. We're using specific joins and composite columns, so a straight CSV export of the table data from your own tools won't work - please use this script.

Usage

Export from Drupal

Run the following command:

mysql -u <user> -p <my-drupal-database> < drupal-blog-importer/tools/export.sql

Import into SilverStripe

Run the following command in the SilverStripe webroot:

sake dev/tasks/DrupalBlogImporterTask postFile=/tmp/posts.csv userFile=/tmp/users.csv commentFile=/tmp/comments.csv

You can leave out arguments to only import partial data.

Available arguments:

postFile: Absolute or relative path of CSV file for blog posts
commentFile: Absolute or relative path of CSV file for comments
userFile: Absolute or relative path of CSV file for users
publish: Publish created blog pages?

Extending the importer

The importer might not fully fit your requirements. E.g, tags might be imported with the "blogcategories" module as many-many relationships, or comment authors imported with nicknames matching their profile on the ["forum" module].

The CSV import logic is based on a core class, CSVBulkLoader. It provides a lot of flexibility in transforming and remapping data. Each type (users, comments, posts) has their own loader class, which can be subclassed.

:::php
class MyDrupalBlogPostBulkLoader extends DrupalBlogPostBulkLoader {
	public $columnMap = array(
		'tags' => '->importTags',
		// ...
	);
	protected function importTags($obj, $val, $record) {
		// Example: Look up many-many relation, and add new objects
	}
}

Simply instruct the dependency injector to use those classes instead (e.g. in mysite/_config/injector.yml):

Injector:
	DrupalBlogPostBulkLoader:
		class: MyDrupalBlogPostBulkLoader

Limitations

Blog post revision history is discarded
Blog post subscriptions by registered users are discarded
Blog post access control is ignored
Comment threads are flattened
Users don't have a public profile or the ability to log in
Tags are not weighted, term hierarchies are flattened
View counts are not kept updated (unless specifically implemented)

chillu / drupal-blog-importer

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