docs: add basic docs for batch feature

docs/conf.py

@@ -43,6 +43,7 @@ intersphinx_mapping = {
     "rich": ("https://rich.readthedocs.io/en/latest/", None),
     "sqlalchemy": ("http://docs.sqlalchemy.org/en/latest/", None),
     "wutta-continuum": ("https://docs.wuttaproject.org/wutta-continuum/", None),
+    "wuttasync": ("https://docs.wuttaproject.org/wuttasync/", None),
 }
 
 

docs/glossary.rst

@@ -77,16 +77,15 @@ Glossary
       See also :class:`~wuttjamaican.auth.AuthHandler`.
 
    batch
-     This refers to a process whereby bulk data operations may be
+     This refers to a feature whereby bulk data operations may be
      performed, with preview and other tools to allow the user to
-     refine as needed before "executing" the batch.
+     refine as needed before "executing" the batch.  For more info see
+     :doc:`narr/batch/index`.
 
      The term "batch" may refer to such a feature overall, or the
      :term:`data model` used, or the specific data for a single batch,
-     etc.
-
-     See also :term:`batch handler` and :term:`batch row`, and the
-     :class:`~wuttjamaican.db.model.batch.BatchMixin` base class.
+     etc.  See also :term:`batch type`, :term:`batch handler` and
+     :term:`batch row`.
 
    batch handler
      This refers to a :term:`handler` meant to process a given type of
@@ -94,7 +93,7 @@ Glossary
 
      There may be multiple handlers registered for a given
      :term:`batch type`, but (usually) only one will be configured for
-     use.
+     use.  See also :doc:`narr/batch/handlers`.
 
    batch row
      A row of data within a :term:`batch`.

docs/index.rst

@@ -64,6 +64,7 @@ Contents
    narr/email/index
    narr/handlers/index
    narr/providers/index
+   narr/batch/index
 
 .. toctree::
    :maxdepth: 1

docs/narr/batch/handlers.rst

@@ -0,0 +1,38 @@
+
+Batch Handlers
+==============
+
+The :term:`batch handler` is responsible for all logic surrounding a
+:term:`batch`: creation, updates, execution.
+
+Each batch handler is associated with one :term:`batch type`.  There
+may be more than one handler defined for a given batch type.  However
+only one handler will be designated as the "default" for each batch
+type (based on config and app defaults).
+
+
+Class Definition
+----------------
+
+A new batch handler class should inherit from
+:class:`~wuttjamaican.batch.BatchHandler`, which provides most of the
+typical housekeeping logic etc.
+
+Note that it also must declare the
+:attr:`~wuttjamaican.batch.BatchHandler.model_class`, which ultimately
+determines the handler's :term:`batch type`.
+
+You will need to define/override some methods for the new handler to
+be useful::
+
+   from wuttjamaican.batch import BatchHandler
+   from poser.db.model import InventoryBatch
+
+   class InventoryBatchHandler(BatchHandler):
+       """ Handler for inventory count batches """
+
+       # direct reference to batch model class
+       model_class = InventoryBatch
+
+       def execute(self, batch, user=None, progress=None, **kwargs):
+           """ export batch row data to CSV """

docs/narr/batch/index.rst

@@ -0,0 +1,49 @@
+
+Batches
+=======
+
+A :term:`batch` is essentially a temporary table with row data of a
+certain type, which can be previewed and finalized before "executing"
+it.  For instance it might be used to handle import of CSV files
+uploaded by the user, but there are many other use cases.
+
+.. note::
+
+   While a batch may be used to import data, these are different
+   concepts.  A true data import process is normally automated, with
+   no preview tooling per se.  A batch normally has preview tooling
+   but its execution may or may not import data per se.
+
+   For true data import see :doc:`wuttasync:index`.
+
+The batch concept (as used here) comes from Rattail; see also
+:doc:`rattail:narr/batches`.
+
+Each batch will be of a certain :term:`batch type`.  Each instance of
+the :term:`app` will have just one :term:`batch handler` responsible
+for each batch type.
+
+Batch data may come from CSV file, SQL query, external API etc.  In
+some cases (e.g. creating a purchase order, or counting inventory) the
+data is added over time by the user.
+
+The user can review all data in the batch before executing.  Some
+batches may allow the user to add/remove/modify rows (or other data)
+in the batch prior to execution.
+
+Upon execution the batch handler's
+:meth:`~wuttjamaican.batch.BatchHandler.execute()` method is invoked,
+so that will determine what is done with the batch data.  Once a batch
+is executed, it is "frozen" with no further modifications allowed to
+it.
+
+
+.. toctree::
+   :maxdepth: 3
+
+   model
+   handlers
+
+
+.. image:: https://rattailproject.org/images/batch-pattern.png
+

docs/narr/batch/model.rst

@@ -0,0 +1,74 @@
+
+Batch Models
+============
+
+Each :term:`batch type` will involve 2 tables in the :term:`app
+database`.  Each table is mapped to a :term:`data model` as shown
+below.
+
+Note that the model should only describe the data structure; all logic
+belongs in the :term:`batch handler`.
+
+
+Batch (header)
+--------------
+
+The model class for the batch header should inherit from
+:class:`~wuttjamaican.db.model.batch.BatchMixin`, which gives it the
+base set of columns for identifying the batch creator/executor etc.
+
+Declaring the
+:attr:`~wuttjamaican.db.model.batch.BatchMixin.batch_type` is
+optional; if not specified the table name is used.  Remember the batch
+type is used for batch handler lookup (among other things).
+
+Additional columns may be added as needed, per the nature of the batch
+type::
+
+   import sqlalchemy as sa
+   from wuttjamaican.db import model
+
+   class InventoryBatch(model.BatchMixin, model.Base):
+       """ Simple batch for counting inventory. """
+
+       # name of table within the app DB
+       __tablename__ = "poser_batch_inventory"
+
+       # unique identifier for this batch type
+       batch_type = "inventory"
+
+       device = sa.Column(sa.String(length=255), nullable=True, doc="""
+       Name of the scanning device used when counting.
+       """)
+
+
+Batch Row
+---------
+
+The model class for batch rows should inherit from
+:class:`~wuttjamaican.db.model.batch.BatchRowMixin`, which gives it
+the base set of columns for tracking status etc.
+
+Note that it also must declare the
+:attr:`~wuttjamaican.db.model.batch.BatchRowMixin.__batch_class__` for
+things to work correctly.
+
+Additional columns may be added as needed, per the nature of the batch
+type::
+
+   class InventoryBatchRow(model.BatchRowMixin, model.Base):
+       """ Item entry row for inventory counting. """
+
+       # name of table within the app DB
+       __tablename__ = "poser_batch_inventory_row"
+
+       # direct reference to batch model class
+       __batch_class__ = InventoryBatch
+
+       scancode = sa.Column(sa.String(length=14), nullable=False, doc="""
+       Scanned UPC of the item.
+       """)
+
+       quantity = sa.Column(sa.Numeric(precision=6, scale=2), nullable=False, default=0, doc="""
+       Quantity of the item.
+       """)