## GoaOAuthProvider GoaOAuthProvider — Abstract base class for OAuth 1.0a providers |

## Synopsis

    struct              GoaOAuthProvider;
    struct              GoaOAuthProviderClass;
    const gchar *       goa_oauth_provider_get_authentication_cookie
                                                            (GoaOAuthProvider *provider);
    const gchar *       goa_oauth_provider_get_request_uri  (GoaOAuthProvider *provider);
    gchar **            goa_oauth_provider_get_request_uri_params
                                                            (GoaOAuthProvider *provider);
    const gchar *       goa_oauth_provider_get_authorization_uri
                                                            (GoaOAuthProvider *provider);
    const gchar *       goa_oauth_provider_get_token_uri    (GoaOAuthProvider *provider);
    const gchar *       goa_oauth_provider_get_callback_uri (GoaOAuthProvider *provider);
    const gchar *       goa_oauth_provider_get_consumer_key (GoaOAuthProvider *provider);
    const gchar *       goa_oauth_provider_get_consumer_secret
                                                            (GoaOAuthProvider *provider);
    gchar *             goa_oauth_provider_build_authorization_uri
                                                            (GoaOAuthProvider *provider,
                                                             const gchar *authorization_uri,
                                                             const gchar *escaped_oauth_token);
    gboolean            goa_oauth_provider_get_use_external_browser
                                                            (GoaOAuthProvider *provider);
    gboolean            goa_oauth_provider_get_use_mobile_browser
                                                            (GoaOAuthProvider *provider);
    gboolean            goa_oauth_provider_is_deny_node     (GoaOAuthProvider *provider,
                                                             WebKitDOMNode *node);
    gboolean            goa_oauth_provider_is_identity_node (GoaOAuthProvider *provider,
                                                             WebKitDOMHTMLInputElement *element);
    gboolean            goa_oauth_provider_is_password_node (GoaOAuthProvider *provider,
                                                             WebKitDOMHTMLInputElement *element);
    void                goa_oauth_provider_add_account_key_values
                                                            (GoaOAuthProvider *provider,
                                                             GVariantBuilder *builder);
    gchar *             goa_oauth_provider_get_identity_sync
                                                            (GoaOAuthProvider *provider,
                                                             const gchar *access_token,
                                                             const gchar *access_token_secret,
                                                             gchar **out_presentation_identity,
                                                             GCancellable *cancellable,
                                                             GError **error);
    gchar *             goa_oauth_provider_get_access_token_sync
                                                            (GoaOAuthProvider *provider,
                                                             GoaObject *object,
                                                             gboolean force_refresh,
                                                             gchar **out_access_token_secret,
                                                             gint *out_access_token_expires_in,
                                                             GCancellable *cancellable,
                                                             GError **error);
    gchar *             goa_oauth_provider_parse_request_token_error
                                                            (GoaOAuthProvider *provider,
                                                             RestProxyCall *call);

## Object Hierarchy

      GObject
       +----GoaProvider
             +----GoaOAuthProvider
                   +----GoaYahooProvider
                   +----GoaTwitterProvider
                   +----GoaFlickrProvider

## Description

GoaOAuthProvider is an abstract base class for OAuth 1.0a compliant implementations as defined by RFC 5849. Additionally, the code works with providers implementing OAuth Session 1.0 Draft 1 for refreshing access tokens.

Subclasses must implement GoaOAuthProviderClass.get_consumer_key, GoaOAuthProviderClass.get_consumer_secret, GoaOAuthProviderClass.get_request_uri, GoaOAuthProviderClass.get_authorization_uri, GoaOAuthProviderClass.get_token_uri, GoaOAuthProviderClass.get_callback_uri and GoaOAuthProviderClass.get_identity_sync methods.

Additionally, the GoaProviderClass.get_provider_type, GoaProviderClass.get_provider_name, GoaProviderClass.build_object (this should chain up to its parent class) methods must be implemented.

Note that the GoaProviderClass.add_account, GoaProviderClass.refresh_account and GoaProviderClass.ensure_credentials_sync methods do not need to be implemented - this type implements these methods.

## Details

### struct GoaOAuthProvider

    struct GoaOAuthProvider;

The GoaOAuthProvider structure contains only private data and should only be accessed using the provided API.

### struct GoaOAuthProviderClass

    struct GoaOAuthProviderClass {
      GoaProviderClass parent_class;

      /* pure virtual */
      const gchar *(*get_consumer_key)             (GoaOAuthProvider             *provider);
      const gchar *(*get_consumer_secret)          (GoaOAuthProvider             *provider);
      const gchar *(*get_request_uri)              (GoaOAuthProvider             *provider);
      const gchar *(*get_authorization_uri)        (GoaOAuthProvider             *provider);
      const gchar *(*get_token_uri)                (GoaOAuthProvider             *provider);
      const gchar *(*get_callback_uri)             (GoaOAuthProvider             *provider);
      const gchar *(*get_authentication_cookie)    (GoaOAuthProvider             *provider);

      gchar       *(*get_identity_sync)            (GoaOAuthProvider             *provider,
                                                    const gchar                  *access_token,
                                                    const gchar                  *access_token_secret,
                                                    gchar                       **out_presentation_identity,
                                                    GCancellable                 *cancellable,
                                                    GError                      **error);

      gchar       *(*parse_request_token_error)    (GoaOAuthProvider             *provider,
                                                    RestProxyCall                *call);

      /* virtual but with default implementation */
      gchar       *(*build_authorization_uri)      (GoaOAuthProvider             *provider,
                                                    const gchar                  *authorization_uri,
                                                    const gchar                  *escaped_oauth_token);
      gboolean     (*get_use_external_browser)     (GoaOAuthProvider             *provider);
      gboolean     (*get_use_mobile_browser)       (GoaOAuthProvider             *provider);
      gchar      **(*get_request_uri_params)       (GoaOAuthProvider             *provider);
      void         (*add_account_key_values)       (GoaOAuthProvider             *provider,
                                                    GVariantBuilder              *builder);

      /* pure virtual */
      gboolean     (*is_deny_node)                 (GoaOAuthProvider             *provider,
                                                    WebKitDOMNode                *node);
      gboolean     (*is_identity_node)             (GoaOAuthProvider             *provider,
                                                    WebKitDOMHTMLInputElement    *element);

      /* virtual but with default implementation */
      gboolean     (*is_password_node)             (GoaOAuthProvider             *provider,
                                                    WebKitDOMHTMLInputElement    *element);
    };

Class structure for GoaOAuthProvider.

GoaProviderClass `parent_class`; | The parent class.
`get_consumer_key` () | Virtual function for `goa_oauth_provider_get_consumer_key()`.
`get_consumer_secret` () | Virtual function for `goa_oauth_provider_get_consumer_secret()`.
`get_request_uri` () | Virtual function for `goa_oauth_provider_get_request_uri()`.
`get_authorization_uri` () | Virtual function for `goa_oauth_provider_get_authorization_uri()`.
`get_token_uri` () | Virtual function for `goa_oauth_provider_get_token_uri()`.
`get_callback_uri` () | Virtual function for `goa_oauth_provider_get_callback_uri()`.
`get_authentication_cookie` () | Virtual function for `goa_oauth_provider_get_authentication_cookie()`.
`get_identity_sync` () | Virtual function for `goa_oauth_provider_get_identity_sync()`.
`parse_request_token_error` () | Virtual function for `goa_oauth_provider_parse_request_token_error()`.
`build_authorization_uri` () | Virtual function for `goa_oauth_provider_build_authorization_uri()`.
`get_use_external_browser` () | Virtual function for `goa_oauth_provider_get_use_external_browser()`.
`get_use_mobile_browser` () | Virtual function for `goa_oauth_provider_get_use_mobile_browser()`.
`get_request_uri_params` () | Virtual function for `goa_oauth_provider_get_request_uri_params()`.
`add_account_key_values` () | Virtual function for `goa_oauth_provider_add_account_key_values()`.
`is_deny_node` () | Virtual function for `goa_oauth_provider_is_deny_node()`.
`is_identity_node` () | Virtual function for `goa_oauth_provider_is_identity_node()`.
`is_password_node` () | Virtual function for `goa_oauth_provider_is_password_node()`.

### goa_oauth_provider_get_authentication_cookie ()

    const gchar *       goa_oauth_provider_get_authentication_cookie
                                                            (GoaOAuthProvider *provider);

Gets the name of a cookie whose presence indicates that the user has been able to log in during the authorization step. This is used to modify the embedded web browser UI that is presented to the user.

This is a pure virtual method - a subclass must provide an implementation.

`provider` : | A GoaOAuthProvider.
Returns : | A string owned by `provider` - do not free. [transfer none]

### goa_oauth_provider_get_request_uri ()

    const gchar *       goa_oauth_provider_get_request_uri  (GoaOAuthProvider *provider);

Gets the request uri.

http://tools.ietf.org/html/rfc5849section-2.1

This is a pure virtual method - a subclass must provide an implementation.

`provider` : | A GoaOAuthProvider.
Returns : | A string owned by `provider` - do not free. [transfer none]

### goa_oauth_provider_get_request_uri_params ()

    gchar **            goa_oauth_provider_get_request_uri_params
                                                            (GoaOAuthProvider *provider);

Gets additional parameters for the request URI.

http://tools.ietf.org/html/rfc5849section-2.1

This is a virtual method where the default implementation returns `NULL`.

`provider` : | A GoaOAuthProvider.
Returns : | `NULL` (for no parameters) or a `NULL`-terminated array of (key, value) pairs that will be added to the URI. The caller will free the returned value with `g_strfreev()`. [transfer full]

### goa_oauth_provider_get_authorization_uri ()

    const gchar *       goa_oauth_provider_get_authorization_uri
                                                            (GoaOAuthProvider *provider);

Gets the authorization uri.

http://tools.ietf.org/html/rfc5849section-2.2

This is a pure virtual method - a subclass must provide an implementation.

`provider` : | A GoaOAuthProvider.
Returns : | A string owned by `provider` - do not free. [transfer none]

### goa_oauth_provider_get_token_uri ()

    const gchar *       goa_oauth_provider_get_token_uri    (GoaOAuthProvider *provider);

Gets the token uri.

http://tools.ietf.org/html/rfc5849section-2.3

This is a pure virtual method - a subclass must provide an implementation.

`provider` : | A GoaOAuthProvider.
Returns : | A string owned by `provider` - do not free. [transfer none]

### goa_oauth_provider_get_callback_uri ()

    const gchar *       goa_oauth_provider_get_callback_uri (GoaOAuthProvider *provider);

Gets the callback uri.

http://tools.ietf.org/html/rfc5849section-2.1

This is a pure virtual method - a subclass must provide an implementation.

`provider` : | A GoaOAuthProvider.
Returns : | A string owned by `provider` - do not free. [transfer none]

### goa_oauth_provider_get_consumer_key ()

    const gchar *       goa_oauth_provider_get_consumer_key (GoaOAuthProvider *provider);

Gets the consumer key identifying the client.

This is a pure virtual method - a subclass must provide an implementation.

`provider` : | A GoaOAuthProvider.
Returns : | A string owned by `provider` - do not free. [transfer none]

### goa_oauth_provider_get_consumer_secret ()

    const gchar *       goa_oauth_provider_get_consumer_secret
                                                            (GoaOAuthProvider *provider);

Gets the consumer secret identifying the client.

This is a pure virtual method - a subclass must provide an implementation.

`provider` : | A GoaOAuthProvider.
Returns : | A string owned by `provider` - do not free. [transfer none]

### goa_oauth_provider_build_authorization_uri ()

    gchar *             goa_oauth_provider_build_authorization_uri
                                                            (GoaOAuthProvider *provider,
                                                             const gchar *authorization_uri,
                                                             const gchar *escaped_oauth_token);

Builds the URI that can be opened in a web browser (or embedded web browser widget) to start authenticating an user.

The default implementation just returns the expected URI (e.g. `http://example.com/dialog/oauth?auth_token=1234567890`)

- override (and chain up) if you e.g. need to to pass additional parameters.

The `authorization_uri` parameter originate from the result of the the `goa_oauth_provider_get_authorization_uri()` method. The `escaped_oauth_token` parameter is the temporary credentials identifier escaped using `g_uri_escape_string()`.

`provider` : | A GoaOAuthProvider.
`authorization_uri` : | An authorization URI.
`escaped_oauth_token` : | An escaped oauth token.
Returns : | An authorization URI that must be freed with `g_free()`. [transfer full]

### goa_oauth_provider_get_use_external_browser ()

    gboolean            goa_oauth_provider_get_use_external_browser
                                                            (GoaOAuthProvider *provider);

Returns whether an external browser (the users default browser) should be used for user interaction.

If an external browser is used, then the dialogs presented in `goa_provider_add_account()` and `goa_provider_refresh_account()` will show a simple "Paste authorization code here" instructions along with an entry and button.

This is a virtual method where the default implementation returns `FALSE`.

`provider` : | A GoaOAuthProvider.
Returns : | `TRUE` if the user interaction should happen in an external browser, `FALSE` to use an embedded browser widget.

### goa_oauth_provider_get_use_mobile_browser ()

    gboolean            goa_oauth_provider_get_use_mobile_browser
                                                            (GoaOAuthProvider *provider);

Returns whether there is a need for the embedded browser to identify itself as running on a mobile phone in order to get a more compact version of the approval page.

This is a virtual method where the default implementation returns `FALSE`.

`provider` : | A GoaOAuthProvider.
Returns : | `TRUE` if the embedded browser should identify itself as running on a mobile platform, `FALSE` otherwise.

### goa_oauth_provider_is_deny_node ()

    gboolean            goa_oauth_provider_is_deny_node     (GoaOAuthProvider *provider,
                                                             WebKitDOMNode *node);

Checks whether `node` is the HTML UI element that the user can use to deny permission to access his account. Usually they are either a WebKitDOMHTMLButtonElement or a WebKitDOMHTMLInputElement.

Please note that providers may have multiple such elements in their UI and this method should catch all of them.

This is a pure virtual method - a subclass must provide an implementation.

`provider` : | A GoaOAuthProvider.
`node` : | A WebKitDOMNode.
Returns : | `TRUE` if the `node` can be used to deny permission.

### goa_oauth_provider_is_identity_node ()

    gboolean            goa_oauth_provider_is_identity_node (GoaOAuthProvider *provider,
                                                             WebKitDOMHTMLInputElement *element);

Checks whether `element` is the HTML UI element that the user can use to identify herself at the provider.

This is a pure virtual method - a subclass must provide an implementation.

`provider` : | A GoaOAuthProvider.
`element` : | A WebKitDOMHTMLInputElement.
Returns : | `TRUE` if the `element` can be used to deny permission.

### goa_oauth_provider_is_password_node ()

    gboolean            goa_oauth_provider_is_password_node (GoaOAuthProvider *provider,
                                                             WebKitDOMHTMLInputElement *element);

Checks whether `element` is the HTML UI element that the user can use to enter her password.

This is a virtual method where the default implementation returns `FALSE`.

`provider` : | A GoaOAuthProvider.
`element` : | A WebKitDOMHTMLInputElement
Returns : | `TRUE` if `element` can be used to enter the password.

### goa_oauth_provider_add_account_key_values ()

    void                goa_oauth_provider_add_account_key_values
                                                            (GoaOAuthProvider *provider,
                                                             GVariantBuilder *builder);

Hook for implementations to add key/value pairs to the key-file when creating an account.

This is a virtual method where the default implementation does nothing.

`provider` : | A GoaProvider.
`builder` : | A GVariantBuilder for a `a{ss}` variant.

### goa_oauth_provider_get_identity_sync ()

    gchar *             goa_oauth_provider_get_identity_sync
                                                            (GoaOAuthProvider *provider,
                                                             const gchar *access_token,
                                                             const gchar *access_token_secret,
                                                             gchar **out_presentation_identity,
                                                             GCancellable *cancellable,
                                                             GError **error);

Method that returns the identity corresponding to `access_token` and `access_token_secret`.

The identity is needed because all authentication happens out of band. In addition to the identity, an implementation also returns a presentation identity that is more suitable for presentation (the identity could be a GUID for example).

The calling thread is blocked while the identity is obtained.

This is a pure virtual method - a subclass must provide an implementation.

`provider` : | A GoaOAuthProvider.
`access_token` : | A valid OAuth 1.0 access token.
`access_token_secret` : | The valid secret for `access_token`.
`out_presentation_identity` : | Return location for presentation identity or `NULL`. [out]
`cancellable` : | A GCancellable or `NULL`. [allow-none]
`error` : | Return location for error or `NULL`.
Returns : | The identity or `NULL` if error is set. The returned string must be freed with `g_free()`.

### goa_oauth_provider_get_access_token_sync ()

    gchar *             goa_oauth_provider_get_access_token_sync
                                                            (GoaOAuthProvider *provider,
                                                             GoaObject *object,
                                                             gboolean force_refresh,
                                                             gchar **out_access_token_secret,
                                                             gint *out_access_token_expires_in,
                                                             GCancellable *cancellable,
                                                             GError **error);

Synchronously gets an access token for `object`. The calling thread is blocked while the operation is pending.

The resulting token is typically read from the local cache so most of the time only a local roundtrip to the storage for the token cache (e.g. gnome-keyring-daemon) is needed. However, the operation may involve refreshing the token with the service provider so a full network round-trip may be needed.

Note that multiple calls are serialized to avoid multiple outstanding requests to the service provider.

This operation may fail if e.g. unable to refresh the credentials or if network connectivity is not available. Note that even if a token is returned, the returned token isn't guaranteed to work - use `goa_provider_ensure_credentials_sync()` if you need stronger guarantees.

`provider` : | A GoaOAuthProvider.
`object` : | A GoaObject.
`force_refresh` : | If set to `TRUE`, forces a refresh of the access token, if possible.
`out_access_token_secret` : | The secret for the return access token. [out]
`out_access_token_expires_in` : | Return location for how many seconds the returned token is valid for (0 if unknown) or `NULL`. [out]
`cancellable` : | A GCancellable or `NULL`. [allow-none]
`error` : | Return location for error or `NULL`.
Returns : | The access token or `NULL` if error is set. The returned string must be freed with `g_free()`.

### goa_oauth_provider_parse_request_token_error ()

    gchar *             goa_oauth_provider_parse_request_token_error
                                                            (GoaOAuthProvider *provider,
                                                             RestProxyCall *call);

Tries to parse the headers and payload within `call` to provide a human readable error message in case the request token could not be fetched.

This is a pure virtual method - a subclass must provide an implementation.

`provider` : | A GoaOAuthProvider.
`call` : | The RestProxyCall that was used to fetch the request token.
Returns : | A human readable error message or `NULL` if the cause of the error could not be determined. The returned string must be freed with `g_free()`.