Django Reports

This project aim is to provide a simple database driven reporting engine that output json and highcharts formatted data.

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Highcharts

The module highcharts has some spcialized classes for highcharts preformatted json output. The following examples illustrate a bar chart, a group pie chart and a stacked bar chart. More highcharts model will be supported in the future.

Pie Charts

The class PieChartReportQuery specify 4 abstract methods that need to be implemented:

get_series_data(self, **kwargs):	takes any number of keyword parameters and returns an array of data points of the format [{"name": "<label>", "y": <value>}
get_series_name(self, **kwargs):	takes any number of keyword parameters and returns a string
get_title(self, **kwargs):	takes any number of keyword parameters and returns a string
get_form(self, **kwargs):	takes any number of keyword parameters and returns an array of dictionaries that define the filter form for the report. The specific format depends on the form standard.

from django_reports.highcharts import PieChartReportQuery
from my_app.models import Product, Sale, Category
from django.db.models import Count

FIELD_NAMES = {
    "Product": "product__id__in",
    "Category": "category__id__in",
}

class SalesQuery(PieChartReportQuery):

    def get_series_data(self, **kwargs):
        selected_fields = kwargs.get("selected_fields",{})
        selected_fields = {FIELD_NAMES[f]:selected_fields[f] for f in selected_fields.keys() if len(selected_fields[f]) > 0}
        objects = Sale.objects.all()
        if len(selected_fields.keys()) > 0:
            objects = objects.filter(**selected_fields)
        return [{"name": r['product__name'], "y": r['total']} for r in
            objects.values('product__name').annotate(
                total=Count('product__name')).order_by('total')]

    def get_series_name(self, **kwargs):
        return "Sales"

    def get_title(self, **kwargs):
        return "Sales"

    def get_form(self, **kwargs):
        return [
            {"title":"Product", "type": "dropdown", "options": [(r.id, r.name) for r in Product.objects.all()], "selected": []},
            {"title":"Category", "type": "dropdown", "options": [(r.id, r.name) for r in Category.objects.all()], "selected": []},
        ]


query = SalesQuery()

Grouped and Stacked Bar Charts

BarChartReportQuery implements both stacked and group bar charts. The interfaces is slightly more complex than for pie charts as this charts support multiple series. The data method requires therefore an identifier that you can then use to select the appropriate data. You also need to provide x labels and series names. These are the methods that you need to implement:

get_series_data(self, series, **kwargs):	takes the series name and any number of keyword parameters and returns an array of data points of the values
get_series_names(self, **kwargs):	takes any number of keyword parameters and returns an array of strings
get_x_labels(self, **kwargs):	takes any number of keyword parameters and returns an array of strings
get_title(self, **kwargs):	takes any number of keyword parameters and returns a string
get_form(self, **kwargs):	takes any number of keyword parameters and returns an array of dictionaries that define the filter form for the report. The specific format depends on the form standard.

Optionally you can also implement get_series_stack to use grouped style or multiple stacks

get_series_stack(self, series, **kwargs):	takes the series name and any number of keyword parameters and returns the name of the stack that this series should use. series with the same stack name will be stacked and series with different series names will be shown side by side. So to implement a grouped style barchart you can implement this method and return series. Not implementing this method will result in a stacked chart

from django_reports.highcharts import PieChartReportQuery
from my_app.models import Product, Sale, Category
from django.db.models import Count

FIELD_NAMES = {
    "Product": "product__id__in",
    "Category": "category__id__in",
}

class SalesQuery(PieChartReportQuery):

    def get_series_names(self, series, **kwargs):
        return Category.object.all().values_list("name",flat=True)

    def get_series_data(self, series, **kwargs):
        selected_fields = kwargs.get("selected_fields",{})
        selected_fields = {FIELD_NAMES[f]:selected_fields[f] for f in selected_fields.keys() if len(selected_fields[f]) > 0}
        objects = Sale.objects.filter(category__name=series)
        if len(selected_fields.keys()) > 0:
            objects = objects.filter(**selected_fields)
        return [r['total']} for r in
            objects.values('product__name').annotate(
                total=Count('product__name')).order_by('product__name')]

    def get_x_labels(self, **kwargs):
        return Product.objects.all().order_by('name').values_list("name",flat=True)

    def get_series_name(self, **kwargs):
        return "Sales"

    def get_title(self, **kwargs):
        return "Sales"

    def get_form(self, **kwargs):
        return [
            {"title":"Product", "type": "dropdown", "options": [(r.id, r.name) for r in Product.objects.all()], "selected": []},
            {"title":"Category", "type": "dropdown", "options": [(r.id, r.name) for r in Category.objects.all()], "selected": []},
        ]

query = SalesQuery()