.. _sardana-recorder-api:

============
Recorder API
============

Recorders are the Sardana plugins in charge of delivering scan data to its
destinations, for example a file, the Spock output or a plot. This page is
the reference of the recorder-writing API. For a step-by-step recipe on how
to develop your own recorder see :ref:`sardana-writing-recorders`.

Base classes
------------

Custom recorders are written by subclassing one of the base classes of the
`sardana.macroserver.scan.recorder` package:

.. currentmodule:: sardana.macroserver.scan.recorder

.. autosummary::

    DataRecorder
    BaseFileRecorder
    DataHandler

* `DataRecorder` -- base class of all recorders. Implement its
  ``_startRecordList``, ``_writeRecord`` and ``_endRecordList`` methods to
  process scan data records.
* `BaseFileRecorder` -- base class for recorders which write data to a file.
  File recorders are implicitly selected based on the extensions declared in
  their ``formats`` attribute (see :ref:`scanfile` and :ref:`scanrecorder`).
* `DataHandler` -- the fan-out object which dispatches each scan record to
  all the active recorders.

More specialized bases are also available in the same package:
``BaseNEXUS_FileRecorder`` and ``BaseNAPI_FileRecorder`` (defined in
`sardana.macroserver.scan.recorder.storage`) for NeXus file recorders and
``BaseSharedMemoryRecorder`` (defined in
`sardana.macroserver.scan.recorder.sharedmemory`) for shared memory
recorders.

Module documentation
--------------------

The full autogenerated documentation of the recorder package is available
at :doc:`api/sardana/macroserver/scan/recorder`.