# Axios Extension

The `@sap-ux/axios-extension` module is an extension of the link:https://github.com/axios/axios[axios] framework adding convenience methods to interact with SAP systems especially with OData services..

## Features

### Factories
The module offers factory functions allowing to generate `ServiceProvider` instances.

### Service Provider
The base service provider extends the class `Axios` abstracting whether it is running in SAP Business Application Studio or locally.

It offers convenience methods to simplify the handling of:

* different versions of S/4 HANA systems
* different authentication methods in the SAP ecosystem.
* running locally or in SAP Business Application Studio

It exposes the `service(path)` method that creates a new Axios instance for the requested service. It will reuse authentication details and cookies from the provider.

### ABAP Service Provider
Another extension of the base provider handling specifics for ABAP based backend systems. It offers simplified access to the catalog services as well as the UI5 ABAP repository service.

### Services
The generic OData service simplifies the access to the service metadata as well as the access to response data. It is used as base class for

#### Catalog Service
Simplified consumption of the SAP catalog service useful for fetching annotations.

#### ABAP UI5 Repository Service
Allows deployment of applications to the UI5 ABAP Repository as well as checking deployed applications.

#### App Index Service
A class representing the app index service allowing to search applications deployed on an ABAP system.

#### Layered Repository Service
Allows deployment of adaptation projects.

Usage:
```Typescript
import { createForAbap } from '@sap-ux/axios-extension';

const provider = createForAbap({
    baseURL: 'https://sap.example',
    params: { 'sap-client': client }
});
const service = provider.getLayeredRepository();
await service.deploy('./dist/my-variant-webapp.zip', {
    namespace: 'apps/my.base.app/appVariants/customer.variant/',
    package: 'MY_PACKAGE',
    transport: 'ABC123'
});
```

#### ADT Service
Services that supports Fiori project deployment configuration. The following example shows the usage
of loading ADT service ```TransportRequestService``` for creating a new transport request number.

Usage:
```Typescript
import { createForAbap } from '@sap-ux/axios-extension';

const provider = createForAbap({
    baseURL: 'https://sap.example',
    params: { 'sap-client': client }
});
const transportRequestService = provider.getAdtService<TransportRequestService>(TransportRequestService);
const newTrNumber = await transportRequestService.createTransportRequest({
    packageName: 'Z_PACKAGE',
    ui5AppName: 'zappname',
    description: 'A new transport request number for deployment'
});
```
#### ADT Service Implementation
Supported ADT services are implemented in link:./src/abap/adt-catalog/services[src/abap/adt-catalog/services].

Take link:./src/abap/adt-catalog/services/ato-service.ts[AtoService] as an example to illustrate how to implement an ADT service.
A specific ADT service implementation like AtoService is implemented as a subclass of link:./src/abap/adt-catalog/services/adt-service.ts[AdtService]. 

```Typescript
export class AtoService extends AdtService {
    // ...
}
```

As a subclass of AdtService, AtoService implements the `getAdtCatagory()` static method to provide the AdtCatagory properties. 
AdtCatagory properties is used as unique ID to
obtain service schema from ADT discovery schema. See link:./src/abap/adt-catalog/adt-catalog-service.ts[AdtCatalogService] and 
link:./src/abap/adt-catalog/adt-schema-store.ts[AdtSchemaStore] for details.

Finally, AtoService implements the request for fetching ATO settings and the parsing of response data. See `getAtoInfo()` and
`parseAtoResponse(xml: string)` in AtoService implementation.

## Installation
Npm

`npm install --save @sap-ux/axios-extension`

Yarn

`yarn add @sap-ux/axios-extension`

Pnpm

`pnpm add @sap-ux/axios-extension`

## Usage
```Typescript
import { createForAbap } from '@sap-ux/axios-extension';

const provider = createForAbap({
    baseURL: 'https://sap.example',
    params: { 'sap-client': client }
});
const service = provider.service('/ns/my_service');
const metadata = await service.metadata();

```
See more examples in link:./test/factory.test.ts[/test/factory.test.ts]

## Proxy Support

To enable support for TLS (Transport Layer Security) connections when using `HTTPS_PROXY`, update your environment by setting the `HTTPS_PROXY` environment variable, as shown;

```bash
export HTTPS_PROXY=<YOUR-PROXY:PORT>
```

In order to support credentials in the proxy URL, you can set the `HTTPS_PROXY` environment variable to include the username and password in the URL. For example:

```bash
export HTTPS_PROXY=http://user:password@proxy.domain.com:3128
```

Ensure you restart any running processes to apply the changes.

Example Scenario

If you're using a proxy server to route your HTTPS traffic, the proxy server will need to create a secure, TLS-encrypted connection to the target server on your behalf. `tls.connect()` will be used to establish that encrypted tunnel between your client, the proxy, and the server.