Minimal App for Reading the Metadata of Published OData Services on SAP's Dev Center Server

A proof-of-concept demo app that calls version 2 of the OData service CATALOGSERVICE on SAP's public Dev Center server.

In this minimal demo scenario, the metadata XML for the selected service is simply returned to the browser as plain text. This XML can then be saved locally and used by the parse-sap-odata crate for building an interface to that OData Service.

Prerequisites

To access SAP's demmo OData server, you must already have a userid and password for the SAP Dev Center server sapes5.sapdevcenter.com.

1. Clone this repo

2. cd read_sap_odata_catalog

3. Create a .env file containing your SAP DevCenter userid and password and the hostname of the OData server whose service catalog you wish to read.

   SAP_USER=<your userid>
   SAP_PASSWORD=<your password>
   SAP_CATALOGSERVICE_HOSTNAME=sapes5.sapdevcenter.com
   

Assuming that your own Gateway server shares the same version of the CATALOGSERVICE OData service, you could enter the hostname of your server, plus your own logon credentials.

Limitations

This is a PoC app and has been built with the assumption that the Gateway server will accept basic authentication. No other authentication methods are currently supported.

Local Execution

Once the .env file has been created, you can start the app using cargo run.

Visit http://localhost:8080 and you will first see a drop down list containing the available catalogs available on this server. In the case of SAP's Demo OData server sapes5.sapdevcenter.com, there is only one service catalog to choose from (ES5):

Once you display the services in the selected catalog, you will see:

You can now choose an OData service and display it's metadata.

When building an interface to an OData Service, create your own Rust project that has a build dependency on parse-sap-odata.

Your project also needs to contain an /odata folder within which you have stored this XML in a file called <service_name>.xml.

WARNNING

Just because an OData service is listed in the dropdown, does not mean it can be invoked. In a Gateway server, it is possible to partially define an OData service!

Consequently, you will see the service name listed, but you will not be able to invoke it.

In order to discover whether or not a service can be invoked, you must attempt to display its service document.

Consequently, you may see error messages such as these:

or

It is also possible that an OData service has been defined, but not activated. In which case, you will see this message: