ORACC server

The ORACC server is hosted at University of Pennsylvania (Philadelphia) and maintained by Prof. Steve Tinney.

It provides with SOAP web services for validation and lemmatisation of ATF files, as well as other advanced uses not yet implemented in Nammu.

Nammu acts as a SOAP client, requesting the server to validate and lemmatise ATF files, and then presents the server output in the GUI.

SOAP

SOAP (Simple Object Access Protocol) is a protocol specification for exchanging structured information in the implementation of web services via HTTP. It attaches XML text in WSDL (Web Service Domain Language) as part of the HTTP request exchanged in the communication.

The ORACC server is a SOAP server, and it's permanently listening for new SOAP requests coming from clients like Nammu. The type of requests Nammu does at the moment are for lemmatising and validating ATF files, although the server provides with more functionality which Nammu will consume in future stages of development.

The communication with the SOAP server occurs in an asynchronous way, meaning that Nammu won't obtain a lemmatised file right after it requests so, since it takes some time for the ORACC server to prepare the response. Instead, these are the steps followed when validating or lemmatising a file:

1. Nammu sends an HTTP POST requests to Nammu containing the project ID, the command that it wants to run (validate, lemmatise, etc.) and the encoded ATF file.

2. The ORACC server acknowledges it has received the request and returns a request_id identifying the process whilst it starts to unpack the ATF and perform the action requested by Nammu.

3. Nammu receives the request_id and asks the ORACC server via HTTP GET if the process associated to that request_id is done. Nammu will keep on doing this until the server is done, there's an error in the server or it times out.

4. When the server is done, it returns a done string to the client.

5. Once Nammu knows the server is done, it sends another HTTP POST request asking for the results of the process requested in step 1. The HTTP POST contains a SOAP Envelope containing the request_id so the server can return the appropriate results.

6. Finally, the server packs the results of the ATF processing/validation/lemmatisation in a zip file encoded in an HTTP POST, which Nammu receives, extracts and presents to the user.