Added support for Google's 'scope' param

src/main/java/org/scribe/builder/ServiceBuilder.java

@@ -20,6 +20,7 @@ public class ServiceBuilder
   private String apiSecret;
   private String callback;
   private Api api;
+  private String scope;
   
   public ServiceBuilder()
   {
@@ -92,6 +93,18 @@ public class ServiceBuilder
     return this;
   }
   
+  /**
+   * Configures the OAuth scope. This is only necessary in some APIs (like Google's).
+   * 
+   * @param scope The OAuth scope
+   * @return the {@link ServiceBuilder} instance for method chaining
+   */
+  public ServiceBuilder scope(String scope)
+  {
+    this.scope = scope;
+    return this;
+  }
+  
   /**
    * Returns the fully configured {@link OAuthService}
    * 
@@ -102,6 +115,6 @@ public class ServiceBuilder
     Preconditions.checkNotNull(api, "You must specify a valid api through the provider() method");
     Preconditions.checkEmptyString(apiKey, "You must provide an api key");
     Preconditions.checkEmptyString(apiSecret, "You must provide an api secret");
-    return api.createService(apiKey, apiSecret, callback);
+    return api.createService(apiKey, apiSecret, callback, scope);
   }
 }

src/main/java/org/scribe/builder/api/Api.java

@@ -20,4 +20,16 @@ public interface Api
    * @return fully configured {@link OAuthService}
    */
   OAuthService createService(String apiKey, String apiSecret, String callback);
+  
+  /**
+   * Creates an {@link OAuthService}
+   * 
+   * @param apiKey your application api key
+   * @param apiSecret your application api secret
+   * @param callback the callback url (or 'oob' for out of band OAuth)
+   * @param scope the OAuth scope
+   * 
+   * @return fully configured {@link OAuthService}
+   */
+  OAuthService createService(String apiKey, String apiSecret, String callback, String scope);
 }

src/main/java/org/scribe/builder/api/DefaultApi10a.java

@@ -50,7 +50,6 @@ public abstract class DefaultApi10a implements Api
   public abstract String getRequestTokenEndpoint();
   public abstract String getAccessTokenEndpoint();
   
-  @Override
   public OAuthService createService(String apiKey, String apiSecret, String callback)
   {
     return new OAuth10aServiceImpl( getSignatureService(), 
@@ -61,6 +60,13 @@ public abstract class DefaultApi10a implements Api
                                     getAccessTokenExtractor(), 
                                     createConfig(apiKey, apiSecret, callback));
   }
+  
+  public OAuthService createService(String apiKey, String apiSecret, String callback, String scope)
+  {
+    OAuthService service = createService(apiKey, apiSecret, callback);
+    service.addScope(scope);
+    return service;
+  }
 
   private OAuthConfig createConfig(String apiKey, String apiSecret, String callback)
   {

src/main/java/org/scribe/model/OAuthConstants.java

@@ -38,4 +38,5 @@ public class OAuthConstants
   public static final String VERIFIER = "oauth_verifier";
   public static final String HEADER = "Authorization";
   public static final Token EMPTY_TOKEN = new Token("", "");
+  public static final String SCOPE = "scope";
 }

src/main/java/org/scribe/oauth/OAuth10aServiceImpl.java

@@ -6,7 +6,7 @@ import org.scribe.services.*;
 
 public class OAuth10aServiceImpl implements OAuthService
 {
-
+  private static final String NO_SCOPE = null;
   private static final String VERSION = "1.0";
 
   private OAuthConfig config;
@@ -16,6 +16,7 @@ public class OAuth10aServiceImpl implements OAuthService
   private HeaderExtractor headerExtractor;
   private RequestTokenExtractor rtExtractor;
   private AccessTokenExtractor atExtractor;
+  private String scope;
 
   public OAuth10aServiceImpl(SignatureService signatureService, TimestampService timestampService, BaseStringExtractor baseStringExtractor,
       HeaderExtractor headerExtractor, RequestTokenExtractor rtExtractor, AccessTokenExtractor atExtractor, OAuthConfig config)
@@ -27,6 +28,7 @@ public class OAuth10aServiceImpl implements OAuthService
     this.rtExtractor = rtExtractor;
     this.atExtractor = atExtractor;
     this.config = config;
+    this.scope = NO_SCOPE;
   }
 
   public Token getRequestToken()
@@ -47,6 +49,10 @@ public class OAuth10aServiceImpl implements OAuthService
     request.addOAuthParameter(OAuthConstants.VERSION, getVersion());
     request.addOAuthParameter(OAuthConstants.CALLBACK, config.getCallback());
     request.addOAuthParameter(OAuthConstants.SIGNATURE, getSignature(request, token));
+    if(scope != NO_SCOPE)
+    {
+      request.addOAuthParameter(OAuthConstants.SCOPE, scope);
+    }
   }
 
   public Token getAccessToken(Token requestToken, Verifier verifier)
@@ -72,6 +78,11 @@ public class OAuth10aServiceImpl implements OAuthService
     return VERSION;
   }
 
+  public void addScope(String scope)
+  {
+    this.scope = scope;
+  }
+  
   private String getSignature(OAuthRequest request, Token token)
   {
     String baseString = baseStringExtractor.extract(request);

src/main/java/org/scribe/oauth/OAuthService.java

@@ -11,4 +11,6 @@ public interface OAuthService
   public void signRequest(Token accessToken, OAuthRequest request);
 
   public String getVersion();
+
+  public void addScope(String scope);
 }