- General Concepts
- Execution Order
- Available plugin hooks
- octoprint.accesscontrol.appkey
- octoprint.cli.commands
- octoprint.comm.protocol.action
- octoprint.comm.protocol.gcode.<phase>
- octoprint.comm.protocol.gcode.received
- octoprint.comm.protocol.scripts
- octoprint.comm.transport.serial.factory
- octoprint.filemanager.extension_tree
- octoprint.filemanager.preprocessor
- octoprint.printer.factory
- octoprint.server.http.bodysize
- octoprint.server.http.routes
- octoprint.ui.web.templatetypes
Hooks are the smaller siblings of :ref:`mixins <sec-plugins-mixins>`, allowing to extend functionality or data processing where a custom mixin type
would be too much overhead. Where mixins are based on classes, hooks are based on methods. Like with the mixin
implementations, plugins inform OctoPrint about hook handlers using a control property, __plugin_hooks__.
This control property is a dictionary consisting of the implemented hooks' names as keys and either the hook callback or a 2-tuple of hook callback and order value as value.
Each hook defines a contract detailing the call parameters for the hook handler method and the expected return type. OctoPrint will call the hook with the define parameters and process the result depending on the hook.
An example for a hook within OctoPrint is octoprint.comm.protocol.scripts, which allows adding additional
lines to OctoPrint's :ref:`GCODE scripts <sec-features-gcode_scripts>`, either as prefix (before the existing lines)
or as postfix (after the existing lines).
self._gcode_hooks = self._pluginManager.get_hooks("octoprint.comm.protocol.scripts")
# ...
for hook in self._gcodescript_hooks:
try:
retval = self._gcodescript_hooks[hook](self, "gcode", scriptName)
except:
self._logger.exception("Error while processing gcodescript hook %s" % hook)
else:
if retval is None:
continue
if not isinstance(retval, (list, tuple)) or not len(retval) == 2:
continue
def to_list(data):
if isinstance(data, str):
data = map(str.strip, data.split("\n"))
elif isinstance(data, unicode):
data = map(unicode.strip, data.split("\n"))
if isinstance(data, (list, tuple)):
return list(data)
else:
return None
prefix, suffix = map(to_list, retval)
if prefix:
scriptLines = list(prefix) + scriptLines
if suffix:
scriptLines += list(suffix)As you can see, the hook's method signature is defined to take the current self (as in, the current comm layer instance),
the general type of script for which to look for additions ("gcode") and the script name for which to look (e.g.
beforePrintStarted for the GCODE script executed before the beginning of a print job). The hook is expected to
return a 2-tuple of prefix and postfix if has something for either of those, otherwise None. OctoPrint will then take
care to add prefix and suffix as necessary after a small round of preprocessing.
Plugins can easily add their own hooks too. For example, the Software Update Plugin declares a custom hook "octoprint.plugin.softwareupdate.check_config" which other plugins can add handlers for in order to register themselves with the Software Update Plugin by returning their own update check configuration.
If you want your hook handler to be an instance method of a mixin implementation of your plugin (for example since you
need access to instance variables handed to your implementation via mixin invocations), you can get this work
by using a small trick. Instead of defining it directly via __plugin_hooks__ utilize the __plugin_load__
property instead, manually instantiate your implementation instance and then add its hook handler method to the
__plugin_hooks__ property and itself to the __plugin_implementation__ property. See the following example.
.. onlineinclude:: https://raw.githubusercontent.com/OctoPrint/Plugin-Examples/master/custom_action_command.py :linenos: :tab-width: 4 :caption: `custom_action_command.py <https://github.com/OctoPrint/Plugin-Examples/blob/master/custom_action_command.py>`_ :name: sec-plugin-concepts-hooks-example
Hooks may also define an order number to allow influencing the execution order of the registered hook handlers. Instead of registering only a callback as hook handler, it is also possible to register a 2-tuple consisting of a callback and an integer value used for ordering handlers. They way this works is that OctoPrint will first sort all registered hook handlers with a order number, taking their identifier as the second sorting criteria, then after that append all hook handlers without a order number sorted only by their identifier.
An example should help clear this up. Let's assume we have the following plugin ordertest which defines a new
hook called octoprint.plugin.ordertest.callback:
import octoprint.plugin
class OrderTestPlugin(octoprint.plugin.StartupPlugin):
def get_sorting_key(self, sorting_context):
return 10
def on_startup(self, *args, **kwargs):
self._logger.info("############### Order Test Plugin: StartupPlugin.on_startup called")
hooks = self._plugin_manager.get_hooks("octoprint.plugin.ordertest.callback")
for name, hook in hooks.items():
hook()
def on_after_startup(self):
self._logger.info("############### Order Test Plugin: StartupPlugin.on_after_startup called")
__plugin_name__ = "Order Test"
__plugin_version__ = "0.1.0"
__plugin_implementation__ = OrderTestPlugin()And these three plugins defining handlers for that hook:
import logging
def callback(*args, **kwargs):
logging.getLogger("octoprint.plugins." + __name__).info("Callback called in oneorderedhook")
__plugin_name__ = "One Ordered Hook"
__plugin_version__ = "0.1.0"
__plugin_hooks__ = {
"octoprint.plugin.ordertest.callback": (callback, 1)
}import logging
def callback(*args, **kwargs):
logging.getLogger("octoprint.plugins." + __name__).info("Callback called in anotherorderedhook")
__plugin_name__ = "Another Ordered Hook"
__plugin_version__ = "0.1.0"
__plugin_hooks__ = {
"octoprint.plugin.ordertest.callback": (callback, 2)
}import logging
def callback(*args, **kwargs):
logging.getLogger("octoprint.plugins." + __name__).info("Callback called in yetanotherhook")
__plugin_name__ = "Yet Another Hook"
__plugin_version__ = "0.1.0"
__plugin_hooks__ = {
"octoprint.plugin.ordertest.callback": callback
}Both orderedhook.py and anotherorderedhook.py not only define a handler callback in the hook registration,
but actually a 2-tuple consisting of a callback and an order number. yetanotherhook.py only defines a callback.
OctoPrint will sort these hooks so that orderedhook will be called first, then anotherorderedhook, then
yetanotherhook. Just going by the identifiers, the expected order would be anotherorderedhook, orderedhook,
yetanotherhook, but since orderedhook defines a lower order number (1) than anotherorderedhook (2),
it will be sorted before anotherorderedhook. If you copy those files into your ~/.octoprint/plugins folder
and start up OctoPrint, you'll see output like this:
[...]
2016-03-24 09:29:21,342 - octoprint.plugins.ordertest - INFO - ############### Order Test Plugin: StartupPlugin.on_startup called
2016-03-24 09:29:21,355 - octoprint.plugins.oneorderedhook - INFO - Callback called in oneorderedhook
2016-03-24 09:29:21,357 - octoprint.plugins.anotherorderedhook - INFO - Callback called in anotherorderedhook
2016-03-24 09:29:21,358 - octoprint.plugins.yetanotherhook - INFO - Callback called in yetanotherhook
[...]
2016-03-24 09:29:21,861 - octoprint.plugins.ordertest - INFO - ############### Order Test Plugin: StartupPlugin.on_after_startup called
[...]
Note
All of the hooks below take at least two parameters, *args and **kwargs. Make sure those are
always present in your hook handler declaration.
They will act as placeholders if additional parameters are added to the hooks in the future and will allow
your plugin to stay compatible to OctoPrint without any necessary adjustments from you in these cases.
- octoprint.accesscontrol.appkey
- octoprint.cli.commands
- octoprint.comm.protocol.action
- octoprint.comm.protocol.gcode.<phase>
- octoprint.comm.protocol.gcode.received
- octoprint.comm.protocol.scripts
- octoprint.comm.transport.serial.factory
- octoprint.filemanager.extension_tree
- octoprint.filemanager.preprocessor
- octoprint.printer.factory
- octoprint.server.http.bodysize
- octoprint.server.http.routes
- octoprint.ui.web.templatetypes
.. py:function:: acl_appkey_hook(*args, **kwargs) By handling this hook plugins may register additional :ref:`App session key providers <sec-api-apps-sessionkey>` within the system. Overrides this to return your additional app information to be used for validating app session keys. You'll need to return a list of 3-tuples of the format (id, version, public key). The ``id`` should be the (unique) identifier of the app. Using a domain prefix might make sense here, e.g. ``org.octoprint.example.MyApp``. ``version`` should be a string specifying the version of the app for which the public key is valid. You can provide the string ``any`` here, in which case the provided public key will be valid for all versions of the app for which no specific public key is defined. Finally, the public key is expected to be provided as a PKCS1 string without newlines. :return: A list of 3-tuples as described above :rtype: list
.. py:function:: cli_commands_hook(cli_group, pass_octoprint_ctx, *args, **kwargs)
By providing a handler for this hook plugins may register commands on OctoPrint's command line interface (CLI).
Handlers are expected to return a list of callables annotated as `Click commands <http://click.pocoo.org/5/>`_ to register with the
CLI.
The custom ``MultiCommand`` instance :class:`~octoprint.cli.plugins.OctoPrintPluginCommands` is provided
as parameter. Via that object handlers may access the *global* :class:`~octoprint.settings.Settings`
and the :class:`~octoprint.plugin.core.PluginManager` instance as ``cli_group.settings`` and ``cli_group.plugin_manager``.
**Example:**
Registers two new commands, ``custom_cli_command:greet`` and ``custom_cli_command:random`` with
OctoPrint:
.. onlineinclude:: https://raw.githubusercontent.com/OctoPrint/Plugin-Examples/master/custom_cli_command.py
:linenos:
:tab-width: 4
:caption: `custom_cli_command.py <https://github.com/OctoPrint/Plugin-Examples/blob/master/custom_cli_command.py>`_
Calling ``octoprint plugins --help`` shows the two new commands:
.. code-block:: none
$ octoprint plugins --help
Usage: octoprint plugins [OPTIONS] COMMAND [ARGS]...
Additional commands provided by plugins.
Options:
--help Show this message and exit.
Commands:
custom_cli_command:greet Greet someone by name, the greeting can be...
custom_cli_command:random Greet someone by name with a random greeting.
softwareupdate:check Check for updates.
softwareupdate:update Apply updates.
Each also has an individual help output:
.. code-block:: none
$ octoprint plugins custom_cli_command:greet --help
Usage: octoprint plugins custom_cli_command:greet [OPTIONS] [NAME]
Greet someone by name, the greeting can be customized.
Options:
-g, --greeting TEXT The greeting to use
--help Show this message and exit.
$ octoprint plugins custom_cli_command:random --help
Usage: octoprint plugins custom_cli_command:random [OPTIONS] [NAME]
Greet someone by name with a random greeting.
Options:
--help Show this message and exit.
And of course they work too:
.. code-block:: none
$ octoprint plugins custom_cli_command:greet
Hello World!
$ octoprint plugins custom_cli_command:greet --greeting "Good morning"
Good morning World!
$ octoprint plugins custom_cli_command:random stranger
Hola stranger!
.. note::
If your hook handler is an instance method of a plugin mixin implementation, be aware that the hook will be
called without OctoPrint initializing your implementation instance. That means that **none** of the
:ref:`injected properties <sec-plugins-mixins-injectedproperties>` will be available and also the
:meth:`~octoprint.plugin.Plugin.initialize` method will not be called.
Your hook handler will have access to the plugin manager as ``cli_group.plugin_manager`` and to the
*global* settings as ``cli_group.settings``. You can have your handler turn the latter into a
:class:`~octoprint.plugin.PluginSettings` instance by using :func:`octoprint.plugin.plugin_settings_from_settings_plugin`
if your plugin's implementation implements the :class:`~octoprint.plugin.SettingsPlugin` mixin and inject
that and the plugin manager instance yourself:
.. code-block:: python
import octoprint.plugin
class MyPlugin(octoprint.plugin.SettingsPlugin):
def get_cli_commands(self, cli_group, pass_octoprint_ctx, *args, **kwargs):
import logging
settings = cli_group._settings
plugin_settings = octoprint.plugin.plugin_settings_for_settings_plugin("myplugin", self)
if plugin_settings is None:
# this can happen if anything goes wrong with preparing the PluginSettings instance
return dict()
self._settings = plugin_settings
self._plugin_manager = cli_group._plugin_manager
self._logger = logging.getLogger(__name__)
### command definition starts here
# ...
No other platform components will be available - the CLI runs outside of a running, fully initialized
OctoPrint server context, so there is absolutely no way to access a printer connection, the event bus or
anything else like that. The only things available are the settings and the plugin manager.
:return: A list of `Click commands or groups <http://click.pocoo.org/5/commands/>`_ to provide on
OctoPrint's CLI.
:rtype: list
.. py:function:: protocol_action_hook(comm_instance, line, action, *args, **kwargs)
React to a :ref:`action command <sec-features-action_commands>` received from the printer.
Hook handlers may use this to react to react to custom firmware messages. OctoPrint parses the received action
command ``line`` and provides the parsed ``action`` (so anything after ``// action:``) to the hook handler.
No returned value is expected.
**Example:**
Logs if the ``custom`` action (``// action:custom``) is received from the printer's firmware.
.. onlineinclude:: https://raw.githubusercontent.com/OctoPrint/Plugin-Examples/master/custom_action_command.py
:linenos:
:tab-width: 4
:caption: `custom_action_command.py <https://github.com/OctoPrint/Plugin-Examples/blob/master/custom_action_command.py>`_
:param object comm_instance: The :class:`~octoprint.util.comm.MachineCom` instance which triggered the hook.
:param str line: The complete line as received from the printer, format ``// action:<command>``
:param str action: The parsed out action command, so for a ``line`` like ``// action:some_command`` this will be
``some_command``
This describes actually four hooks:
octoprint.comm.protocol.gcode.queuingoctoprint.comm.protocol.gcode.queuedoctoprint.comm.protocol.gcode.sendingoctoprint.comm.protocol.gcode.sent
.. py:function:: protocol_gcodephase_hook(comm_instance, phase, cmd, cmd_type, gcode, *args, **kwargs)
Pre- and postprocess commands as they progress through the various phases of being sent to the printer. The phases
are the following:
* ``queuing``: This phase is triggered just before the command is added to the send queue of the communication layer. This
corresponds to the moment a command is being read from a file that is currently being printed. Handlers
may suppress or change commands or their command type here. This is the only phase that supports multi command
expansion by having the handler return a list, see below for details.
* ``queued``: This phase is triggered just after the command was added to the send queue of the communication layer.
No manipulation is possible here anymore (returned values will be ignored).
* ``sending``: This phase is triggered just before the command is actually being sent to the printer. Right afterwards
a line number will be assigned and the command will be sent. Handlers may suppress or change commands here. The
command type is not taken into account anymore.
* ``sent``: This phase is triggered just after the command was handed over to the serial connection to the printer.
No manipulation is possible here anymore (returned values will be ignored). A command that reaches the sent phase
must not necessarily have reached the printer yet and it might also still run into communication problems and a
resend might be triggered for it.
Hook handlers may use this to rewrite or completely suppress certain commands before they enter the send queue of
the communication layer or before they are actually sent over the serial port, or to react to the queuing or sending
of commands after the fact. The hook handler will be called with the processing ``phase``, the ``cmd`` to be sent to
the printer as well as the ``cmd_type`` parameter used for enqueuing (OctoPrint will make sure that the send queue
will never contain more than one line with the same ``cmd_type``) and the detected gcode command (if it is one).
Defining a ``cmd_type`` other than None will make sure OctoPrint takes care of only having one command of that type
in its sending queue. Predefined types are ``temperature_poll`` for temperature polling via ``M105`` and
``sd_status_poll`` for polling the SD printing status via ``M27``.
``phase`` will always match the ``<phase>`` part of the implemented hook (e.g. ``octoprint.comm.protocol.gcode.queued``
handlers will always be called with ``phase`` set to ``queued``). This parameter is provided so that plugins may
utilize the same hook for multiple phases if required.
Handlers are expected to return one of the following result variants:
* ``None``: Don't change anything. Note that Python functions will also automatically return ``None`` if
an empty ``return`` statement is used or just nothing is returned explicitly from the handler. Hence, the following
examples are all falling into this category:
.. code-block:: python
def one(*args, **kwargs):
print("I return None explicitly")
return None
def two(*args, **kwargs):
print("I just return without any values")
return
def three(*args, **kwargs):
print("I don't explicitly return anything at all")
Handlers which do not wish to modify (or suppress) ``cmd`` or ``cmd_type`` at all should use this option.
* A string with the rewritten version of the ``cmd``, e.g. ``return "M110"``. To avoid situations which will be
difficult to debug should the returned command be later changed to ``None`` (with the intent to suppress the
command instead but actually causing ``cmd`` and ``cmd_type`` to just staying as-is), this variant should be
entirely avoided by handlers.
* A 1-tuple consisting of a rewritten version of the ``cmd``, e.g. ``return "M110",``, or ``None`` in order to
suppress the command, e.g. ``return None,``. Handlers which wish to rewrite the command or to suppress it completely
should use this option.
* A 2-tuple consisting of a rewritten version of the ``cmd`` and the ``cmd_type``, e.g. ``return "M105", "temperature_poll"``.
Handlers which wish to rewrite both the command and the command type should use this option.
* A list of any of the above to allow for expanding one command into
many. The following example shows how any queued command could be turned into a sequence of a temperature query,
line number reset, display of the ``gcode`` on the printer's display and finally the actual command (this example
does not make a lot of sense to be quite honest):
.. code-block:: python
def rewrite_foo(self, comm_instance, phase, cmd, cmd_type, gcode, *args, **kwargs):
if gcode or not cmd.startswith("@foo"):
return
return [("M105", "temperature_poll"),
("M110",),
"M117 echo foo: {}".format(cmd)]
Note: Only one command of a given ``cmd_type`` (other than None) may be queued at a time. Trying to rewrite the ``cmd_type``
to one already in the queue will give an error.
**Example**
The following hook handler replaces all ``M107`` ("Fan Off", deprecated) with an ``M106 S0`` ("Fan On" with speed
parameter) upon queuing and logs all sent ``M106``.
.. onlineinclude:: https://raw.githubusercontent.com/OctoPrint/Plugin-Examples/master/rewrite_m107.py
:linenos:
:tab-width: 4
:caption: `rewrite_m107.py <https://github.com/OctoPrint/Plugin-Examples/blob/master/rewrite_m107.py>`_
:param object comm_instance: The :class:`~octoprint.util.comm.MachineCom` instance which triggered the hook.
:param str phase: The current phase in the command progression, either ``queuing``, ``queued``, ``sending`` or
``sent``. Will always match the ``<phase>`` of the hook.
:param str cmd: The GCODE command for which the hook was triggered. This is the full command as taken either
from the currently streamed GCODE file or via other means (e.g. user input our status polling).
:param str cmd_type: Type of command, e.g. ``temperature_poll`` for temperature polling or ``sd_status_poll`` for SD
printing status polling.
:param str gcode: Parsed GCODE command, e.g. ``G0`` or ``M110``, may also be None if no known command could be parsed
:return: None, 1-tuple, 2-tuple or string, see the description above for details.
.. py:function:: gcode_received_hook(comm_instance, line, *args, **kwargs)
Get the returned lines sent by the printer. Handlers should return the received line or in any case, the modified
version of it. If the the handler returns None, processing will be aborted and the communication layer will get an
empty string as the received line. Note that Python functions will also automatically return ``None`` if an empty
``return`` statement is used or just nothing is returned explicitly from the handler.
**Example:**
Looks for the response of an ``M115``, which contains information about the ``MACHINE_TYPE``, among other things.
.. onlineinclude:: https://raw.githubusercontent.com/OctoPrint/Plugin-Examples/master/read_m115_response.py
:linenos:
:tab-width: 4
:caption: `read_m115_response.py <https://github.com/OctoPrint/Plugin-Examples/blob/master/read_m115_response.py>`_
:param MachineCom comm_instance: The :class:`~octoprint.util.comm.MachineCom` instance which triggered the hook.
:param str line: The line received from the printer.
:return: The received line or in any case, a modified version of it.
:rtype: str
.. py:function:: protocol_scripts_hook(comm_instance, script_type, script_name, *args, **kwargs)
Return a prefix to prepend and a postfix to append to the script ``script_name`` of type ``type``. Handlers should
make sure to only proceed with returning additional scripts if the ``script_type`` and ``script_name`` match
handled scripts. If not, None should be returned directly.
If the hook handler has something to add to the specified script, it may return a 2-tuple, with the first entry
defining the prefix (what to *prepend* to the script in question) and the last entry defining the postfix (what to
*append* to the script in question). Both prefix and postfix can be None to signify that nothing should be prepended
respectively appended.
The returned entries may be either iterables of script lines or a string including newlines of the script lines (which
will be split by the caller if necessary).
**Example:**
Appends an ``M117 OctoPrint connected`` to the configured ``afterPrinterConnected`` GCODE script.
.. onlineinclude:: https://raw.githubusercontent.com/OctoPrint/Plugin-Examples/master/message_on_connect.py
:linenos:
:tab-width: 4
:caption: `message_on_connect.py <https://github.com/OctoPrint/Plugin-Examples/blob/master/message_on_connect.py>`_
:param MachineCom comm_instance: The :class:`~octoprint.util.comm.MachineCom` instance which triggered the hook.
:param str script_type: The type of the script for which the hook was called, currently only "gcode" is supported here.
:param str script_name: The name of the script for which the hook was called.
:return: A 2-tuple in the form ``(prefix, postfix)`` or None
:rtype: tuple or None
.. py:function:: serial_factory_hook(comm_instance, port, baudrate, read_timeout, *args, **kwargs)
Return a serial object to use as serial connection to the printer. If a handler cannot create a serial object
for the specified ``port`` (and ``baudrate``), it should just return ``None``.
If the hook handler needs to perform state switches (e.g. for autodetection) or other operations on the
:class:`~octoprint.util.comm.MachineCom` instance, it can use the supplied ``comm_instance`` to do so. Plugin
authors should keep in mind however that due to a pending change in the communication layer of
OctoPrint, that interface will change in the future. Authors are advised to follow OctoPrint's development
closely if directly utilizing :class:`~octoprint.util.comm.MachineCom` functionality.
A valid serial instance is expected to provide the following methods, analogue to PySerial's
`serial.Serial <https://pythonhosted.org//pyserial/pyserial_api.html#serial.Serial>`_:
readline(size=None, eol='\n')
Reads a line from the serial connection, compare `serial.Filelike.readline <https://pythonhosted.org//pyserial/pyserial_api.html#serial.FileLike.readline>`_.
write(data)
Writes data to the serial connection, compare `serial.Filelike.write <https://pythonhosted.org//pyserial/pyserial_api.html#serial.FileLike.write>`_.
close()
Closes the serial connection, compare `serial.Serial.close <https://pythonhosted.org//pyserial/pyserial_api.html#serial.Serial.close>`_.
Additionally setting the following attributes need to be supported if baudrate detection is supposed to work:
baudrate
An integer describing the baudrate to use for the serial connection, compare `serial.Serial.baudrate <https://pythonhosted.org//pyserial/pyserial_api.html#serial.Serial.baudrate>`_.
timeout
An integer describing the read timeout on the serial connection, compare `serial.Serial.timeout <https://pythonhosted.org//pyserial/pyserial_api.html#serial.Serial.timeout>`_.
**Example:**
Serial factory similar to the default one which performs auto detection of the serial port if ``port`` is ``None``
or ``AUTO``.
.. code-block:: python
:linenos:
def default(comm_instance, port, baudrate, connection_timeout):
if port is None or port == 'AUTO':
# no known port, try auto detection
comm_instance._changeState(comm_instance.STATE_DETECT_SERIAL)
serial_obj = comm_instance._detectPort(False)
if serial_obj is None:
comm_instance._log("Failed to autodetect serial port")
comm_instance._errorValue = 'Failed to autodetect serial port.'
comm_instance._changeState(comm_instance.STATE_ERROR)
eventManager().fire(Events.ERROR, {"error": comm_instance.getErrorString()})
return None
else:
# connect to regular serial port
comm_instance._log("Connecting to: %s" % port)
if baudrate == 0:
serial_obj = serial.Serial(str(port), 115200, timeout=connection_timeout, writeTimeout=10000, parity=serial.PARITY_ODD)
else:
serial_obj = serial.Serial(str(port), baudrate, timeout=connection_timeout, writeTimeout=10000, parity=serial.PARITY_ODD)
serial_obj.close()
serial_obj.parity = serial.PARITY_NONE
serial_obj.open()
return serial_obj
:param MachineCom comm_instance: The :class:`~octoprint.util.comm.MachineCom` instance which triggered the hook.
:param str port: The port for which to construct a serial instance. May be ``None`` or ``AUTO`` in which case port
auto detection is to be performed.
:param int baudrate: The baudrate for which to construct a serial instance. May be 0 in which case baudrate auto
detection is to be performed.
:param int read_timeout: The read timeout to set on the serial port.
:return: The constructed serial object ready for use, or ``None`` if the handler could not construct the object.
:rtype: A serial instance implementing implementing the methods ``readline(...)``, ``write(...)``, ``close()`` and
optionally ``baudrate`` and ``timeout`` attributes as described above.
.. py:function:: file_extension_hook(*args, **kwargs)
Return additional entries for the tree of accepted file extensions for uploading/handling by the file manager.
Should return a dictionary to merge with the existing extension tree, adding additional extension groups to
``machinecode`` or ``model`` types.
**Example:**
The following handler would add a new file type "x3g" as accepted ``machinecode`` format, with extensions ``x3g``
and ``s3g``:
.. code-block:: python
:linenos:
def support_x3g_machinecode(*args, **kwargs):
return dict(
machinecode=dict(
x3g=["x3g", "s3g"]
)
)
.. note::
This will only add the supplied extensions to the extension tree, allowing the files to be uploaded and managed
through the file manager. Plugins will need to add further steps to ensure that the files will be processable
in the rest of the system (e.g. handling/preprocessing new machine code file types for printing etc)!
:return: The partial extension tree to merge with the full extension tree.
:rtype: dict
.. py:function:: file_preprocessor_hook(path, file_object, links=None, printer_profile=None, allow_overwrite=False, *args, **kwargs)
Replace the ``file_object`` used for saving added files to storage by calling :func:`~octoprint.filemanager.util.AbstractFileWrapper.save`.
``path`` will be the future path of the file on the storage. The file's name is accessible via
:attr:`~octoprint.filemanager.util.AbstractFileWrapper.filename`.
``file_object`` will be a subclass of :class:`~octoprint.filemanager.util.AbstractFileWrapper`. Handlers may
access the raw data of the file via :func:`~octoprint.filemanager.util.AbstractFileWrapper.stream`, e.g.
to wrap it further. Handlers which do not wish to handle the `file_object`
**Example**
The following plugin example strips all comments from uploaded/generated GCODE files ending on the name postfix ``_strip``.
.. onlineinclude:: https://raw.githubusercontent.com/OctoPrint/Plugin-Examples/master/strip_all_comments.py
:linenos:
:tab-width: 4
:caption: `strip_all_comments.py <https://github.com/OctoPrint/Plugin-Examples/blob/master/strip_all_comments.py>`_
:param str path: The path on storage the `file_object` is to be stored
:param AbstractFileWrapper file_object: The :class:`~octoprint.filemanager.util.AbstractFileWrapper` instance
representing the file object to store.
:param dict links: The links that are going to be stored with the file.
:param dict printer_profile: The printer profile associated with the file.
:param boolean allow_overwrite: Whether to allow overwriting an existing file named the same or not.
:return: The `file_object` as passed in or None, or a replaced version to use instead for further processing.
:rtype: AbstractFileWrapper or None
.. py:function:: printer_factory_hook(components, *args, **kwargs)
Return a :class:`~octoprint.printer.PrinterInstance` instance to use as global printer object. This will
be called only once during initial server startup.
The provided ``components`` is a dictionary containing the already initialized system components:
* ``plugin_manager``: The :class:`~octoprint.plugin.core.PluginManager`
* ``printer_profile_manager``: The :class:`~octoprint.printer.profile.PrinterProfileManager`
* ``event_bus``: The :class:`~octoprint.events.EventManager`
* ``analysis_queue``: The :class:`~octoprint.filemanager.analysis.AnalysisQueue`
* ``slicing_manager``: The :class:`~octoprint.slicing.SlicingManager`
* ``file_manager``: The :class:`~octoprint.filemanager.FileManager`
* ``app_session_manager``: The :class:`~octoprint.server.util.flask.AppSessionManager`
* ``plugin_lifecycle_manager``: The :class:`~octoprint.server.LifecycleManager`
* ``user_manager``: The :class:`~octoprint.users.UserManager`
* ``preemptive_cache``: The :class:`~octoprint.server.util.flask.PreemptiveCache`
If the factory returns anything but ``None``, it will be assigned to the global ``printer`` instance.
If no of the registered factories return a printer instance, the default :class:`~octoprint.printer.standard.Printer`
class will be instantiated.
:param dict components: System components to use for printer instance initialization
:return: The ``printer`` instance to use globally.
:rtype: PrinterInterface subclass or None
.. py:function:: server_bodysize_hook(current_max_body_sizes, *args, **kwargs)
Allows extending the list of custom maximum body sizes on the web server per path and HTTP method with custom entries
from plugins.
Your plugin might need this if you want to allow uploading files larger than 100KB (the default maximum upload size
for anything but the ``/api/files`` endpoint).
``current_max_body_sizes`` will be a (read-only) list of the currently configured maximum body sizes, in case you
want to check from your plugin if you need to even add a new entry.
The hook must return a list of 3-tuples (the list's length can be 0). Each 3-tuple should have the HTTP method
against which to match as first, a regular expression for the path to match against and the maximum body size as
an integer as the third entry.
The path of the route will be prefixed by OctoPrint with ``/plugin/<plugin identifier>/`` (if the path already begins
with a ``/`` that will be stripped first).
.. important::
Implementing this hook will make your plugin require a restart of OctoPrint for enabling/disabling it fully.
**Example**
The following plugin example sets the maximum body size for ``POST`` requests against four custom URLs to 100, 200,
500 and 1024KB. To test its functionality try uploading files larger or smaller than an endpoint's configured maximum
size (as multipart request with the file upload residing in request parameter ``file``) and observe the behaviour.
.. onlineinclude:: https://raw.githubusercontent.com/OctoPrint/Plugin-Examples/master/increase_bodysize.py
:linenos:
:tab-width: 4
:caption: `increase_bodysize.py <https://github.com/OctoPrint/Plugin-Examples/blob/master/increase_bodysize.py>`_
:param list current_max_body_sizes: read-only list of the currently configured maximum body sizes
:return: A list of 3-tuples with additional request specific maximum body sizes as defined above
:rtype: list
.. py:function:: server_route_hook(server_routes, *args, **kwargs)
Allows extending the list of routes registered on the web server.
This is interesting for plugins which want to provide their own download URLs which will then be delivered statically
following the same path structure as regular downloads.
``server_routes`` will be a (read-only) list of the currently defined server routes, in case you want to check from
your plugin against that.
The hook must return a list of 3-tuples (the list's length can be 0). Each 3-tuple should have the path of the route
(a string defining its regular expression) as the first, the `RequestHandler <http://tornado.readthedocs.org/en/branch4.0/web.html#request-handlers>`_
class to use for the route as the second and a dictionary with keywords parameters for the defined request handler as
the third entry.
The path of the route will be prefixed by OctoPrint with ``/plugin/<plugin identifier>/`` (if the path already begins
with a ``/`` that will be stripped first).
.. note::
Static routes provided through this hook take precedence over routes defined through blueprints.
If your plugin also implements the :class:`~octoprint.plugin.BlueprintPlugin` mixin and has defined a route for a
view on that which matches one of the paths provided via its ``octoprint.server.http.routes`` hook handler, the
view of the blueprint will thus not be reachable since processing of the request will directly be handed over
to your defined handler class.
.. important::
Implementing this hook will make your plugin require a restart of OctoPrint for enabling/disabling it fully.
**Example**
The following example registers two new routes ``/plugin/add_tornado_route/download`` and ``/plugin/add_tornado_route/forward``
in the webserver which roughly replicate the functionality of ``/downloads/files/local`` and ``/downloads/camera/current``.
.. onlineinclude:: https://raw.githubusercontent.com/OctoPrint/Plugin-Examples/master/add_tornado_route.py
:linenos:
:tab-width: 4
:caption: `add_tornado_route.py <https://github.com/OctoPrint/Plugin-Examples/blob/master/add_tornado_route.py>`_
.. seealso::
:class:`~octoprint.server.util.tornado.LargeResponseHandler`
Customized `tornado.web.StaticFileHandler <http://tornado.readthedocs.org/en/branch4.0/web.html#tornado.web.StaticFileHandler>`_
that allows delivery of the requested resource as attachment and access validation through an optional callback.
:class:`~octoprint.server.util.tornado.UrlForwardHandler`
`tornado.web.RequestHandler <http://tornado.readthedocs.org/en/branch4.0/web.html#request-handlers>`_ that proxies
requests to a preconfigured url and returns the response.
:param list server_routes: read-only list of the currently configured server routes
:return: a list of 3-tuples with additional routes as defined above
:rtype: list
.. py:function:: templatetype_hook(template_sorting, template_rules, *args, **kwargs)
Allows extending the set of supported template types in the web interface. This is interesting for plugins which want
to offer other plugins to hook into their own offered UIs. Handlers must return a list of additional template
specifications in form of 3-tuples.
The first entry of the tuple must be the name of the template type and will be automatically prefixed with
``plugin_<identifier>_``.
The second entry must be a sorting specification that defines how OctoPrint should sort multiple templates injected
through plugins of this template type. The sorting specification should be a dict with the following possible
entries:
.. list-table::
:widths: 5 95
* - **Key**
- **Description**
* - key
- The sorting key within the template config to use for sorting the list of template injections. This may be
``None`` in which case no sorting will be taking place. Defaults to ``name``.
* - add
- Usually irrelevant for custom template types, only listed for the sake of completeness. The method of adding
the sorted list of template injections from plugins to the template injections from the
core. May be ``append`` to append the list, ``prepend`` to prepend the list, or ``custom_append`` or
``custom_prepend`` to append respectively prepend but going so after preprocessing the entries and order data
with custom functions (e.g. to inject additional entries such as the "Plugins" section header in the settings
dialog). For custom template types this defaults to ``append``.
* - custom_add_entries
- Usually irrelevant for custom template types, only listed for the sake of completeness. Custom preprocessor
for the entries provided through plugins, before they are added to the general template entries
context variable for the current template type.
* - custom_add_order
- Usually irrelevant for custom template types, only listed for the sake of completeness. Custom preprocessor
for the template order provided through plugins, before they are added to the general template order
context variable for the current template type.
The third entry must be a rule specification in form of a dict which tells OctoPrint how to process the template
configuration entries provided by :func:`~octoprint.plugin.TemplatePlugin.get_template_configs` by providing
transformation functions of various kinds:
.. list-table::
:widths: 5 95
* - **Key**
- **Description**
* - div
- Function that returns the id of the container for template content if not explicitly provided by the template
config, input parameter is the name of the plugin providing the currently processed template config. If not
provided this defaults to a lambda function of the form ``lambda x: "<plugin identifier>_<template type>_plugin_" + x``
with ``plugin identifier`` being the identifier of the plugin providing the additional template type.
* - template
- Function that returns the default template filename for a template type to attempt to include in case no
template name is explicitly provided by the template config, input parameter is the name of the plugin providing
the current processed template config. If not provided this defaults to a lambda function of the form
``lambda x: x + "_plugin_<plugin identifier>_<template type>.jinja2"`` with ``plugin identifier`` being the
identifier of the plugin providing the additional template type.
* - to_entry
- Function to transform a template config to the data structure stored in the Jinja context for the injected
template. If not provided this defaults to a lambda function returning a 2-tuple of the ``name`` value of
the template config and the template config itself (``lambda data: (data["name"], data)``)
* - mandatory
- A list of keys that must be included in the template config for this template type. Template configs not containing
all of the keys in this list will be ignored. Defaults to an empty list.
OctoPrint will provide all template configs for custom template types in the Jinja rendering context in the same way
as it provides the template configs for core template types, through the ``templates`` context variable which is a
dict mapping from the template type name (``plugin_<plugin identifier>_<template type>`` for custom ones) to a dict
with ``entries`` and ``order`` values, the first containing a dict of all registered template configs, the latter
an ordered list of all registered template keys of the type in the order they should be rendered. Plugins should
iterate over the ``order`` list and then render each entry utilizing the template entry as provided for the key in
the ``entries`` dict (note that this entry will have the format specified through the ``to_entry`` section in the
template rule).
**Example**
The example consists of two plugins, one providing a custom template type and the other consuming it.
First the provider:
.. onlineinclude:: https://raw.githubusercontent.com/OctoPrint/Plugin-Examples/master/custom_template_provider/__init__.py
:linenos:
:tab-width: 4
:caption: `custom_template_provider/__init__.py <https://github.com/OctoPrint/Plugin-Examples/blob/master/custom_template_provider/__init__.py>`_
.. onlineinclude:: https://raw.githubusercontent.com/OctoPrint/Plugin-Examples/master/custom_template_provider/templates/custom_template_provider_settings.jinja2
:linenos:
:tab-width: 4
:caption: `custom_template_provider/templates/custom_template_provider_settings.jinja2 <https://github.com/OctoPrint/Plugin-Examples/blob/master/custom_template_provider/templates/custom_template_provider_settings.jinja2>`_
Then the consumer:
.. onlineinclude:: https://raw.githubusercontent.com/OctoPrint/Plugin-Examples/master/custom_template_consumer/__init__.py
:linenos:
:tab-width: 4
:caption: `custom_template_consumer/__init__.py <https://github.com/OctoPrint/Plugin-Examples/blob/master/custom_template_consumer/__init__.py>`_
.. onlineinclude:: https://raw.githubusercontent.com/OctoPrint/Plugin-Examples/master/custom_template_consumer/templates/custom_template_consumer_awesometemplate.jinja2
:linenos:
:tab-width: 4
:caption: `custom_template_consumer/templates/custom_template_consumer_awesometemplate.jinja2 <https://github.com/OctoPrint/Plugin-Examples/blob/master/custom_template_consumer/templates/custom_template_consumer_awesometemplate.jinja2>`_
:param dict template_rules: read-only dictionary of currently configured template rules
:param dict template_sorting: read-only dictionary of currently configured template sorting specifications
:return: a list of 3-tuples (template type, rule, sorting spec)
:rtype: list