Establishing a Connection

The objects available within our connector are accessible from the "cdata.xero" module. To use the module's objects directly:

Import the module as follows:
```
import cdata.xero as mod
```
To establish a connection string, call the connect() method from the connector object using an appropriate connection string, such as:
```
mod.connect("InitiateOAuth=GETANDREFRESH;")
```

Connecting to Xero

The connector supports using PKCE applications and OAuth applications. Both PKCE and OAuth connections to Xero are authenticated using OAuth.

When the connector starts, it opens a browser and requests your login information. The connector uses the credentials you provide to access your Xero data. These credentials are saved and automatically refreshed as needed.

To enable this authentication from all OAuth flows, you must set AuthScheme to OAuth, and you must create a custom OAuth application.

The following subsections describe how to authenticate to Xero from three common authentication flows:

Desktop: a connection to a server on the user's local machine, frequently used for testing and prototyping.
Web: access to data via a shared website.
Headless Server: a dedicated computer that provides services to other computers and their users, which is configured to operate without a monitor and keyboard.

For information about how to create a custom OAuth application, see Creating a Custom Authentication Application.

For a complete list of connection string properties available in Xero, see Connection.

Desktop Applications

To authenticate with the credentials for a custom OAuth application, you must get and refresh the OAuth access token. After you do that, you are ready to connect.

Get and refresh the OAuth access token:

InitiateOAuth = GETANDREFRESH. Used to automatically get and refresh the OAuthAccessToken.
OAuthClientId = the client Id assigned when you registered your application.
OAuthClientSecret = the client secret that was assigned when you registered your application.
CallbackURL = the redirect URI that was defined when you registered your application.

When you connect, the connector opens Xero's OAuth endpoint in your default browser. Log in and grant permissions to the application.

After you grant permissions to the application, the connector then completes the OAuth process:

The connector obtains an access token from Xero and uses it to request data.
The OAuth values are saved in the path specified in OAuthSettingsLocation. These values persist across connections.

When the access token expires, the connector refreshes it automatically.

Web Applications

Authenticating via the Web requires you to create and register a custom OAuth application with Xero, as described in Creating a Custom Authentication Application. You can then use the connector to get and manage the OAuth token values.

This section describes how to get the OAuth access token, how to have the driver refresh the OAuth access token automatically, and how to refresh the OAuth access token manually.

Get the OAuth access token:

Set the following connection properties to obtain the OAuthAccessToken:
- OAuthClientId = the client Id in your application settings.
- OAuthClientSecret = the client secret in your application settings.
Call stored procedures to complete the OAuth exchange:
- Call the GetOAuthAuthorizationURL stored procedure. Set the AuthMode input to WEB and the CallbackURL to the Redirect URI you specified in your application settings. The stored procedure returns the URL to the OAuth endpoint.
- Navigate to the URL that the stored procedure returned in Step 1. Log in and authorize the web application. You are redirected back to the callback URL.
- Call the GetOAuthAccessToken stored procedure. Set the AuthMode input to WEB. Set the Verifier input to the code parameter in the query string of the redirect URI.

After you obtain the access and refresh tokens, you can connect to data and refresh the OAuth access token automatically.

Automatic refresh of the OAuth access token:

To have the connector automatically refresh the OAuth access token, do the following:

Before connecting to data for the first time, set the following connection parameters:
- InitiateOAuth = REFRESH.
- OAuthClientId = the client Id in your application settings.
- OAuthClientSecret = the client secret in your application settings.
- OAuthAccessToken = the access token returned by GetOAuthAccessToken.
- OAuthSettingsLocation = the path where you want the connector to save the OAuth values, which persist across connections.
On subsequent data connections, set the following:
- InitiateOAuth
- OAuthSettingsLocation

Manual refresh of the OAuth access token:

The only value needed to manually refresh the OAuth access token is the OAuth refresh token.

To manually refresh the OAuthAccessToken after the ExpiresIn period (returned by GetOAuthAccessToken) has elapsed, call the GetOAuthAccessToken stored procedure.
Set the following connection properties:
- OAuthClientId = the Client Id in your application settings.
- OAuthClientSecret = the Client Secret in your application settings.
Call GetOAuthAccessToken with OAuthRefreshToken set to the OAuth refresh token returned by GetOAuthAccessToken.
After the new tokens have been retrieved, set the OAuthAccessToken property to the value returned by GetOAuthAccessToken. This opens a new connection.

Store the OAuth refresh token so that you can use it to manually refresh the OAuth access token after it has expired.

Headless Machines

If you need to log in to a resource that resides on a headless machine, you must authenticate on another device that has an internet browser. You can do this in either of the following ways:

Option 1: Obtain the OAuthVerifier value.
Option 2: Install the connector on a machine with an internet browser and transfer the OAuth authentication values after you authenticate through the usual browser-based flow.

After you execute either Option 1 or Option 2, configure the driver to automatically refresh the access token on the headless machine.

Option 1: Obtaining and Exchanging a Verifier Code

To obtain a verifier code, you must authenticate at the OAuth authorization URL. Do the following:

Authenticate from the machine with an internet browser, and obtain the OAuthVerifier connection property.

Set the following properties:
- InitiateOAuth = OFF.
- OAuthClientId = the client Id assigned when you registered your application.
- OAuthClientSecret = the client secret assigned when you registered your application.
Call the GetOAuthAuthorizationURL stored procedure. The stored procedure returns the CallbackURL established when the custom OAuth application was registered. (See Creating a Custom Authentication Application.)

Copy this URL and paste it into a new browser tab.
Log in and grant permissions to the connector. The OAuth application redirects you the redirect URI, with a parameter called code appended. Note the value of this parameter; you will need it later, to configure the OAuthVerifier connection property.
Exchange the OAuth verifier code for OAuth refresh and access tokens. On the headless machine, set the following connection properties to obtain the OAuth authentication values:
- InitiateOAuth = REFRESH.
- OAuthVerifier = the noted verifier code (the value of the code parameter in the redirect URI).
- OAuthSettingsLocation = persist the encrypted OAuth authentication values to the specified file.
- OAuthClientId = the client Id in your custom OAuth application settings.
- OAuthClientSecret = the client secret in the custom OAuth application settings.
Test the connection to generate the OAuth settings file.
After you re-set the following properties, you are ready to connect:
- InitiateOAuth = REFRESH.
- OAuthSettingsLocation = the file containing the encrypted OAuth authentication values. To enable the automatic refreshing of the access token, be sure that this file gives read and write permissions to the connector.
- OAuthClientId = the client Id assigned when you registered your application.
- OAuthClientSecret = the client secret assigned when you registered your application.

Option 2: Transferring OAuth Settings

Prior to connecting on a headless machine, you must install and create a connection with the driver on a device that supports an internet browser. Set the connection properties as described above in "Desktop Applications".

After completing the instructions in "Desktop Applications", the resulting authentication values are encrypted and written to the path specified by OAuthSettingsLocation. The default filename is OAuthSettings.txt.

Test the connection to generate the OAuth settings file, then copy the OAuth settings file to your headless machine.

To connect to data via the headless machine, set the following connection properties:

InitiateOAuth = REFRESH
OAuthSettingsLocation = the path to the OAuth settings file you copied from the machine with the browser. To enable automatic refreshing of the access token, ensure that this file gives read and write permissions to the connector.
OAuthClientId = the client Id assigned when you registered your custom OAuth application.
OAuthClientSecret = the client secret assigned when you registered your custom OAuth application.

Connecting to a Xero API

The connector supports several Xero APIs. To connect to them, set the appropriate connection property:

For the Accounting API, set Schema to ACCOUNTING.
For the Australian Payroll API, set Schema to PAYROLLAUS.
For the Files API, set Schema to FILES.
For the Fixed Assets API set Schema to ASSETS.
For the Projects API, set Schema to PROJECTS.

Specifying Permitted Organization Access