OAuth example

To access the Smint.io API for fetching all assets, authentication is needed. Authentication utilizes the OAuth 2.0 standard.

All you need is in the Smint.io library

To help you implement the authentication, Smint.io provides everything you need. There is a separate package for it, that will help you a great deal. See the JavaDoc ISmintIoOAuthAuthorizer and the Smint.io example Application authorizer.

Utilize the package like that:

    dependencies {
        // ...
        implementation (":smintio-clapi-consumer-integration-core:[1.8.0,2.0.0)")
        implementation (":smintio-clapi-consumer-integration-authorizer:[1.8.0,2.0.0)")
        // ...
    }

    <dependencies>

        <!-- ... -->

        <dependency>
            <groupId>io.smint</groupId>
            <artifactId>smintio-clapi-consumer-integration-core</artifactId>
            <version>[1.8.0,2.0.0)</version>
        </dependency>

        <dependency>
            <groupId>io.smint</groupId>
            <artifactId>smintio-clapi-consumer-integration-authorizer</artifactId>
            <version>[1.8.0,2.0.0)</version>
        </dependency>

        <!-- ... -->

    </dependencies>

How it works

Stripped down to the most important part, OAuth works like this:

The user’s browser need to open the authenticaion URL to Smint.io site.
The user will authenticate there and authorize the target DAM to access his Smint.io data.
Smint.io will redirect the browser to the target DAM’s URL, passing the authorization data via GET-parameters.
The DAM’s URL to use is provided by the settings object (see ISettingsModel), which has to be implemented and is passed to this Smint.io library by ISyncTargetFactory. This URL need to be registered manually (via email) with the Smint.io admin, who will add it to the Smint.io server’s whitelist.

To implement these steps you will:

Provide a global context for the HTTP servlet, like a static member in a class or such thing. The HTTP servlet need to access the very same authorizer instance that create the Smint.io authorization URL, as it contains some data to validate the received authorization data.
```
 public abstract class GlobalSmintIoServerContext {
     public ISmintIoOAuthAuthorizer smintioAuthorizer;
 }
```

Create the authentication URL and pass it to the user’s browser (see Smint.io example application implementation).

 GlobalSmintIoServerContext.smintioAuthorizer =
     new SmintIoOAuthAuthorizer(() -> mySettings, tokenStorage);

 final URL urlForUserBrowser = createAuthorizationUrl();

Wait for the user to finish authorization.

Provide an HTTP endpoint to receive authorization data and pass it to the Smint.io authorizer instance created previously (see JavaDoc ISmintIoOAuthAuthorizer).

  public class ReceiveOAuthDataFromServiceViaBrowser extends HttpServlet {

      protected void doGet(HttpServletRequest request, HttpServletResponse response)
          throws ServletException, IOException {

          GlobalSmintIoServerContext.smintioAuthorizer.analyzeAuthorizationData(
              request.getParameterMap()
          );
          GlobalSmintIoServerContext.smintioAuthorizer = null;
      }

  }