usage.md

Example Usage

You want to develop a Rust application that can consume the entity sets exposed by an SAP V2 OData service.

For the purposes of instruction, let's say you're working with a custom OData service that displays services ordered either by functional location or by date:

Rust Application	zcustom-service-orders
OData Service URL	https://my-sap-server.my-domain.com/sap/opu/odata/sap
OData Service Name	ZCUSTOM_SERVICE_ORDERS_SRV
OData Schema Name	ZCUSTOM_SERVICE_ORDERS
Entity Names	SERVICE_ORDERS_BY_FLOC SERVICE_ORDERS_BY_DATE
Entity Type	ZServiceOrder

The general approach to consuming such a service is as follows:

1. Create a new Rust binary application cargo new zcustom-service-orders

2. cd zcustom-service-orders

3. Edit Cargo.toml to include at least the following dependencies

   [build-dependencies]
   parse-sap-odata = { version = "1.4", features = ["parser"]}
   
   [dependencies]
   # Dependencies needed by the code generated by parse-sap-odata
   chrono = { version = "0.4", features = ["serde"]}
   quick-xml = { version = "0.36", features = ["serialize"] }
   rust_decimal = { version = "1", features = ["serde-with-str"]}
   serde = { version = "1.0", features = ["derive"] }
   uuid = { version = "1.8", features = ["serde"]}
   
   # Dependencies needed by this app
   parse-sap-odata = "1.4"
   parse-sap-atom-feed = "1.1"

4. mkdir odata

5. In your browser, visit your OData service's metadata

   E.G. https://my-sap-server.my-domain.com/sap/opu/odata/sap/ZCUSTOM_SERVICE_ORDERS_SRV/$metadata

6. Save the metadata as the file zcustom_service_orders.xml in the odata directory

7. Create a build.rs file in same directory as Cargo.toml and add at least the following:

   use parse_sap_odata::parser::gen_src;
   
   fn main() {
       gen_src("zcustom_service_orders", "ZCUSTOM_SERVICE_ORDERS");
   }

8. In src/main.rs include at least:

   use parse_sap_atom_feed::{atom::feed::Feed, odata_error::ODataError, xml::sanitise_xml};
   use std::str::{self, FromStr};
   
   parse_sap_odata::include_mod!("zcustom_service_orders");
   
   use zcustom_service_orders::*;
   
   fn main() {
      let raw_xml: String = /* Whatever code is needed to fetch the entity set data as a raw XML string */
   
      // You might need to sanitise the raw XML string before attempting to parse it
      let clean_xml = sanitise_xml(raw_xml);
   
      let srv_orders_by_floc = Feed::<ZServiceOrder>::from_str(&clean_xml);
   }