Module reahl.web.interfaces

The interfaces for persisted classes that are needed by the core Reahl framework. Different implementations of the framework can be provided by implementing these.

UserSessionProtocol

class reahl.web.interfaces.UserSessionProtocol

Bases: object

A UserSession represents a potentially lengthy interaction of a particular user with the system.

abstract classmethod for_current_session()

Returns a UserSession instance for the current user. If no UserSession is present for the current interaction yet this method should create one. If a UserSession does exist for the current interaction, this method returns the correct UserSession.

abstract is_active()

Answers whether the session is still usable (instead of being expired due to inactivity).

abstract is_secured()

Answers whether the interaction is currently done via a secure channel where applicable.

Added in version 3.1.

abstract set_last_activity_time()

Sets a timestamp on the UserSession to indicate when the last activity was detected relating to this interaction. UserSessions typically expire automatically if no activity is detected after some time.

abstract get_interface_locale()

Answers a string identifying the currently selected locale.

abstract classmethod get_or_create_session()

Returns a session, creating a new one if none can be determined. If one can be determined from the browser, that session is returned.

abstract set_session_key(response)

Called at the end of a request loop to enable an implementation to save some identifying information to the response (such as setting a cookie with the ID of the current session).

abstract classmethod initialise_web_session_on(context)

Fetch/create a new UserSession or do any initialisation or reinitialisation needed on it and set it on the given context as its .session attribute.

Called at the beginning of a request or after an abort during the request (which may require reinitialisation of the session so it may still be used after the abort).

abstract classmethod preserve_session(session)

Ensure the given session object is kept intact so that it can survive a transaction abort.

Added in version 5.2.

abstract classmethod restore_session(session)

After a transaction is aborted, this ensures the given session is restored to its state before the abort.

Added in version 5.2.

abstract get_csrf_token()

Fetch/create a suitable token for protecting against CSRF.

Added in version 5.2.

UserInputProtocol

class reahl.web.interfaces.UserInputProtocol

Bases: SessionDataProtocol

User input, typed as strings on a form is persisted using this class, for the current user’s session for use in a subsequent request. Used via web.persisted_userinput_class.

abstract classmethod get_previously_entered_for_form(form, input_name, entered_input_type)

Returns the user input associated with the given reahl.web.ui.Form, as previously saved using input_name as name.

Changed in version 4.0: Added entered_input_type

abstract classmethod save_input_value_for_form(form, input_name, value, entered_input_type)

Persists value as the value of the user input associated with the given reahl.web.ui.Form, using input_name as name.

Changed in version 4.0: Added entered_input_type

abstract classmethod get_persisted_for_view(view, key, value_type)

Returns the value associated with the given reahl.web.fw.UrlBoundView, as previously saved using key.

Added in version 5.0.

abstract classmethod add_persisted_for_view(view, key, value, value_type)

Persists value associated with the given reahl.web.fw.UrlBoundView, to be retrieved using key.

Added in version 5.0.

abstract classmethod remove_persisted_for_view(view, key)

Removes previously persisted value with the given reahl.web.fw.UrlBoundView, as previously saved using key

Added in version 5.0.

PersistedExceptionProtocol

class reahl.web.interfaces.PersistedExceptionProtocol

Bases: SessionDataProtocol

When a reahl.component.exceptions.DomainException happens during Form submission, the exception is persisted using this class, for the current user’s session for use in a subsequent request. Used via web.persisted_exception_class.

abstract classmethod clear_for_form_except_inputs(form)

Clears the exception associated with this form, while leaving exeptions for invididual inputs intact.

Added in version 5.0.

abstract classmethod save_exception_for_form(form, **kwargs)

Saves a an exception for the given reahl.web.ui.Form.

Added in version 5.0.

abstract classmethod get_exception_for_form(form)

Retrieves an exception previously saved for the given reahl.web.ui.Form, or None if not found.

abstract classmethod get_exception_for_input(form, input_name)

Retrieves an exception previously saved for the given reahl.web.ui.Form and input_name or None if not found.

abstract classmethod clear_for_all_inputs(form)

Removes all saved Exceptions associated with the given reahl.web.ui.Form.

PersistedFileProtocol

class reahl.web.interfaces.PersistedFileProtocol

Bases: object

When a file is uploaded, file is persisted using this class, for the current user’s session for use in a subsequent request. Used via web.persisted_file_class.

abstract property file_obj

Returns an object with traditional .read and .seek methods which can be used to read the contents of the persisted file.

abstract classmethod clear_for_form(form)

Removes all files previously saved for the given reahl.web.ui.Form.

abstract classmethod get_persisted_for_form(form, input_name)

Returns the previously persisted file for the given reahl.web.ui.Form, using the given input_name as name.

abstract classmethod add_persisted_for_form(form, input_name, uploaded_file)

Saves the given uploaded_file (a reahl.component.modelinterface.UploadedFile) using the given input_name for the given reahl.web.ui.Form.

abstract classmethod remove_persisted_for_form(form, input_name, filename)

Removes previously persisted file with name filename, as saved for the given reahl.web.ui.Form and input_name.

abstract classmethod is_uploaded_for_form(form, input_name, filename)

Answers whether a file with name filename has previously been saved for the given reahl.web.ui.Form and input_name.