GrETEL-upload

GrETEL-upload is an extension package for GrETEL that allows to upload your own corpus or dataset. The application will then automatically transform your corpus in an Alpino XML-treebank. After processing, the treebanks are searchable in GrETEL, and if you supply metadata, you can use these for filtering and analysis.

Local installation

Requirements

On top of a default LAMP installation (with PHP 7.*; PHP 8 is currently not working), the following packages are required:

• basex: Storing processed treebanks into a XML-database.
• php-zip: Required to process .zip-files.
• php-ldap: Authentication via LDAP.
• php-sqlite3: SQLite3 module for PHP, allows tests with in-memory database.
• php-libxml

GrETEL-upload also requires the following external programs to be installed:

• Alpino. Download and then unpack (preferably) into /opt/Alpino/ . You can change the installation directory in the application/config/database_default.php . It also need to be changed in alpino.sh .
• Corpus2alpino. This can be installed globally using sudo -H pip3 install corpus2alpino . This requires Python 3.6+.

It is also possible to install using pip:

bash pip install -r requirements.txt

Make sure to modify config/common.php to point to the install location of corpus2alpino.

Configuration

You will have to provide configuration details in four files:

• application/config/common.php : Paths and other common settings.
• application/config/config.php : CodeIgniter settings.
• application/config/database.php : Settings for your database connection to both the relational database (e.g. MySQL) and the XML-database (basex).
• application/config/ldap.php : Settings for LDAP authentication.

An example configuration for each can be found in application/config/{NAME}_default.php .

Update the apache config, to allow read-write access to gretel-upload (and gretel).

Database schema

Create the mysql database gretel_upload You can use the command php index.php migrate in the source directory to create/migrate the database schema. See docs/schema.png for the current database schema (exported from phpMyAdmin).

Permissions

Make sure the uploads directory is writable for the user running the Apache daemon (usually www-data ). Also create a writable sessions directory and refer to its absolute path in application/config/config.php if using the default files session driver.

Start-up

Start both Alpino and BaseX as server instances by running the following two commands:

basexserver -S
./alpino.sh

Then, navigate to the installation directory in your web browser (e.g. localhost/gretel-upload/ ) to start using GrETEL-upload.

Production: Cron Task

For production servers, a cron job is required for processing uploaded treebanks. Schedule the following e.g. every 5 minutes:

/usr/bin/php {root}/index.php cron process

Uploading corpora

Formats

Currently, three formats are supported: LASSY-XML, CHAT and plain text (UTF-8 encoded). When you upload a set of texts (always in a zipped folder, possibly consisting of multiple directories), you can specify whether the text is already sentence- and/or word-tokenized. If not, the application will do this for you.

Metadata

GrETEL-upload allows metadata annotation using the PaQu metadata format. This metadata will be converted to LASSY-XML during import.

The GrETEL-upload interface then allows you to select which facet you would want to use to filter the data in GrETEL. You can e.g. choose to display a metadata column called 'year' as a slider, dropdown list or set of checkboxes. You can also choose to hide certain columns.

Libraries

PHP

GrETEL-upload is written in PHP and created with CodeIgniter 3.1.11. The application uses the following libraries:

• application/libraries/Alpino.php : Wrapper around Alpino's dependency parser and tokenisation scripts.
• application/libraries/BaseX.php : BaseX PHP connector. Slightly modified to work in CodeIgniter.
• application/libraries/Format.php : Helper to convert between various formats such as XML, JSON, CSV, etc. Part of CodeIgniter Rest Server (see below).
• application/libraries/Ldap.php : Authentication via LDAP. Inspired by the LDAP Authentication library.
• application/libraries/REST_Controller.php : CodeIgniter Rest Server, turns controllers into REST APIs.

Javascript

GrETEL-upload uses the following JavaScript libraries:

• jQuery
• qTip2

CSS

GrETEL-upload is created with Pure CSS.

Images

GrETEL-upload uses the FamFamFam silk icon set.

API

GrETEL-upload has an API for retrieving data from the database:

• treebank/: Returns all publicly available treebanks.
• treebank/show/[title]: Returns the components of the treebank given by title.
• treebank/metadata/[title]: Returns the metadata of the treebank given by title.
• treebank/user/[user_id]: Returns all treebanks available to the currently logged in user. This might include private treebanks.

Tests

The test suite is created using ci-phpunit-test. This uses PHPUnit. You can run the tests by navigating to the application/tests directory and calling phpunit .

Demo

A working version is available on http://gretel.hum.uu.nl.