labthings_fastapi.exceptions ============================ .. py:module:: labthings_fastapi.exceptions .. autoapi-nested-parse:: A submodule for custom LabThings-FastAPI Exceptions. Exceptions ---------- .. autoapisummary:: labthings_fastapi.exceptions.NotConnectedToServerError labthings_fastapi.exceptions.ServerNotRunningError labthings_fastapi.exceptions.ReadOnlyPropertyError labthings_fastapi.exceptions.PropertyNotObservableError labthings_fastapi.exceptions.InconsistentTypeError labthings_fastapi.exceptions.MissingTypeError labthings_fastapi.exceptions.ThingNotConnectedError labthings_fastapi.exceptions.ThingSlotError labthings_fastapi.exceptions.InvocationCancelledError labthings_fastapi.exceptions.InvocationError labthings_fastapi.exceptions.NoInvocationContextError labthings_fastapi.exceptions.LogConfigurationError labthings_fastapi.exceptions.NoBlobManagerError labthings_fastapi.exceptions.UnsupportedConstraintError labthings_fastapi.exceptions.FailedToInvokeActionError labthings_fastapi.exceptions.ServerActionError labthings_fastapi.exceptions.ClientPropertyError Module Contents --------------- .. py:exception:: NotConnectedToServerError Bases: :py:obj:`RuntimeError` The Thing is not connected to a server. This exception is called if an Action is called or a `.DataProperty` is updated on a Thing that is not connected to a ThingServer. A server connection is needed to manage asynchronous behaviour. `.Thing` instances are also only assigned a ``path`` when they are added to a server, so this error may be raised by functions that implement the HTTP API if an attempt is made to construct the API before the `.Thing` has been assigned a path. Initialize self. See help(type(self)) for accurate signature. .. py:exception:: ServerNotRunningError Bases: :py:obj:`RuntimeError` The ThingServer is not running. This exception is called when a function assumes the ThingServer is running, and it is not. This might be because the function needs to call code in the async event loop. Initialize self. See help(type(self)) for accurate signature. .. py:exception:: ReadOnlyPropertyError Bases: :py:obj:`AttributeError` A property is read-only. No setter has been defined for this `.FunctionalProperty`, so it may not be written to. Initialize self. See help(type(self)) for accurate signature. .. py:exception:: PropertyNotObservableError Bases: :py:obj:`RuntimeError` The property is not observable. This exception is raised when `.Thing.observe_property` is called with a property that is not observable. Currently, only data properties are observable: functional properties (using a getter/setter) may not be observed. Initialize self. See help(type(self)) for accurate signature. .. py:exception:: InconsistentTypeError Bases: :py:obj:`TypeError` Different type hints have been given for a descriptor. Some descriptors in LabThings, particularly `.DataProperty` and `.ThingSlot` may have their type specified in different ways. If multiple type hints are provided, they must match. See `.property` for more details. Initialize self. See help(type(self)) for accurate signature. .. py:exception:: MissingTypeError Bases: :py:obj:`TypeError` No type hints have been given for a descriptor that requires a type. Every property and thing connection should have a type hint, There are different ways of providing these type hints. This error indicates that no type hint was found. See documentation for `.property` and `.thing_slot` for more details. Initialize self. See help(type(self)) for accurate signature. .. py:exception:: ThingNotConnectedError Bases: :py:obj:`RuntimeError` `.ThingSlot`\ s have not yet been set up. This error is raised if a `.ThingSlot` is accessed before the `.Thing` has been supplied by the LabThings server. This usually happens because either the `.Thing` is being used without a server (in which case the attribute should be mocked), or because it has been accessed before ``__enter__`` has been called. Initialize self. See help(type(self)) for accurate signature. .. py:exception:: ThingSlotError Bases: :py:obj:`RuntimeError` A `.ThingSlot` could not be set up. This error is raised if the LabThings server is unable to set up a `.ThingSlot`, for example because the named Thing does not exist, or is of the wrong type, or is not specified and there is no default. Initialize self. See help(type(self)) for accurate signature. .. py:exception:: InvocationCancelledError Bases: :py:obj:`BaseException` An invocation was cancelled by the user. Note that this inherits from BaseException so won't be caught by `except Exception`, it must be handled specifically. Action code may want to handle cancellation gracefully. This exception should be propagated if the action's status should be reported as ``cancelled``, or it may be handled so that the action finishes, returns a value, and is marked as ``completed``. If this exception is handled and not re-raised, or if it arises in a manually-created thread, the action will continue as normal. It is a good idea to make sure your action terminates soon after this exception is raised. Initialize self. See help(type(self)) for accurate signature. .. py:exception:: InvocationError Bases: :py:obj:`RuntimeError` The invocation ended in an anticipated error state. When this error is raised, action execution stops as expected. The exception will be logged at error level without a traceback, and the invocation will return with error status. Subclass this error for errors that do not need further traceback information to be provided with the error message in logs. Initialize self. See help(type(self)) for accurate signature. .. py:exception:: NoInvocationContextError Bases: :py:obj:`RuntimeError` An invocation-specific resource has been requested from outside an invocation. This error is raised when the current invocation ID is requested, and there is no current invocation ID. Invocation ID is determined from context (using a `.ContextVar` ) and is available from within action functions. To avoid this error in test code or manually created threads, you should supply an invocation context. Initialize self. See help(type(self)) for accurate signature. .. py:exception:: LogConfigurationError Bases: :py:obj:`RuntimeError` There is a problem with logging configuration. LabThings uses the `logging` module to collect logs from actions. This requires certain handlers and filters to be set up. This exception is raised if they cannot be added, or if they are not present when they are needed. Initialize self. See help(type(self)) for accurate signature. .. py:exception:: NoBlobManagerError Bases: :py:obj:`RuntimeError` Raised if an API route accesses Invocation outputs without a BlobIOContextDep. Any access to an invocation output must have BlobIOContextDep as a dependency, as the output may be a blob, and the blob needs this context to resolve its URL. Initialize self. See help(type(self)) for accurate signature. .. py:exception:: UnsupportedConstraintError Bases: :py:obj:`ValueError` A constraint argument is not supported. This exception is raised when a constraint argument is passed to a property that is not in the supported list. See `labthings_fastapi.properties.CONSTRAINT_ARGS` for the list of supported arguments. Their meaning is described in the `pydantic.Field` documentation. Initialize self. See help(type(self)) for accurate signature. .. py:exception:: FailedToInvokeActionError Bases: :py:obj:`RuntimeError` The action could not be started. This error is raised by a `.ThingClient` instance if an action could not be started. It most commonly occurs because the input to the action could not be converted to the required type: the error message should give more detail on what's wrong. Initialize self. See help(type(self)) for accurate signature. .. py:exception:: ServerActionError Bases: :py:obj:`RuntimeError` The action ended with an error on the server. This error is raised by a `ThingClient` when an action is successfully invoked on the server, but does not complete. The error message should include more information on why this happened. Initialize self. See help(type(self)) for accurate signature. .. py:exception:: ClientPropertyError Bases: :py:obj:`RuntimeError` Setting or getting a property via a ThingClient failed. Initialize self. See help(type(self)) for accurate signature.