## 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`<br>`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`
1. `cd zcustom-service-orders`
1. Edit `Cargo.toml` to include at least the following dependencies

   ```toml
   [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"
   ```
   
1. `mkdir odata`
1. 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`

1. Save the metadata as the file `zcustom_service_orders.xml` in the `odata` directory
1. Create a `build.rs` file in same directory as `Cargo.toml` and add at least the following:

   ```rust
   use parse_sap_odata::parser::gen_src;

   fn main() {
       gen_src("zcustom_service_orders", "ZCUSTOM_SERVICE_ORDERS");
   }
   ```

1. In `src/main.rs` include at least:

   ```rust
   use parse_sap_atom_feed::{atom::feed::Feed, odata_error::ODataError, xml::sanitise_xml};
   use std::str::{self, FromStr};

   include!(concat!(env!("OUT_DIR"), "/zcustom_service_orders.rs"));

   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);
   }
   ```