rattail-manual/docs/data/reports/custom.rst

82 lines
2.5 KiB
ReStructuredText
Raw Normal View History

========================
Adding a Custom Report
========================
We'll start with a simple report which shows all departments and the number of
products for each.
Each type of report has a "key" which uniquely identifies it. For this example
we'll use ``poser_dept_prod_counts`` for the key. Note that it's a good idea
to always use an app-specific prefix (e.g. ``poser_``) in the key.
Typically you will create a new Python module which is named according to the
key. Here we'll create ``~/src/poser/poser/reports/dept_prod_counts.py``, and
in it we'll define the report::
from sqlalchemy import orm
from rattail.reporting import ExcelReport
class DepartmentProductCounts(ExcelReport):
"""
Shows all departments and the number of products for each.
"""
type_key = 'poser_dept_prod_counts'
name = "Department Product Counts"
output_fields = [
'department_number',
'department_name',
'product_count',
]
def make_data(self, session, params, progress=None, **kwargs):
model = self.model
# fetch all departments, with product lists pre-loaded
departments = session.query(model.Department)\
.order_by(model.Department.number)\
.options(orm.joinedload(model.Department.products))\
.all()
rows = []
def add_row(department, i):
rows.append({
'department_number': department.number,
'department_name': department.name,
'product_count': len(department.products),
})
self.progress_loop(add_row, departments, progress,
message="Fetching data for report")
return rows
Then you must register your new report type, to make it available to the app.
This is done within your project's ``setup.py`` file, for instance::
setup(
name = "Poser",
# ...
entry_points = {
'rattail.reports': [
'poser_dept_prod_counts = poser.reports.dept_prod_counts:DepartmentProductCounts',
],
},
)
Once you've added that you must re-install the app to your virtual environment,
for instance:
.. code-block:: sh
cd /srv/envs/poser
source bin/activate
pip install -e ~/src/poser
At this point the report should be available for running within the app. See
:doc:`generate` for more info.