InheritanceΒΆ

Inheritance is useful when you have two or more reports sharing common things.

Example: two reports of Users, one with some fields and another with more fields and landscape page orientation:

import os
cur_dir = os.path.dirname(os.path.abspath(__file__))

from django.contrib.auth.models import User

from reportlab.lib.pagesizes import A4
from reportlab.lib.units import cm
from reportlab.lib.enums import TA_CENTER, TA_RIGHT

from geraldo import Report, ReportBand, Label, ObjectValue, SystemField,\
    BAND_WIDTH, landscape

class UsersReport(Report):
    title = 'Users'

    class band_page_header(ReportBand):
        height = 1.3*cm
        elements = [
            SystemField(expression='%(report_title)s', top=0.1*cm, left=0, width=BAND_WIDTH,
                style={'fontName': 'Helvetica-Bold', 'fontSize': 14, 'alignment': TA_CENTER}),
            Label(text="ID", top=0.8*cm, left=0),
            Label(text="Username", top=0.8*cm, left=3*cm),
            Label(text="First name", top=0.8*cm, left=8*cm),
            Label(text="Last name", top=0.8*cm, left=13*cm),
            Label(text="Staff", top=0.8*cm, left=18*cm),
        ]
        borders = {'bottom': True}

    class band_page_footer(ReportBand):
        height = 0.5*cm
        elements = [
            Label(text='Created with Geraldo Reports', top=0.1*cm),
            SystemField(expression='Printed in %(now:%Y, %b %d)s at %(now:%H:%M)s', top=0.1*cm,
                width=BAND_WIDTH, style={'alignment': TA_RIGHT}),
        ]
        borders = {'top': True}

    class band_detail(ReportBand):
        height = 0.7*cm
        elements = [
            ObjectValue(attribute_name='id', top=0, left=0),
            ObjectValue(attribute_name='username', top=0, left=3*cm, display_format='<font size=14 name=Helvetica>%s</font>'),
            ObjectValue(attribute_name='first_name', top=0, left=8*cm),
            ObjectValue(attribute_name='last_name', top=0, left=13*cm),
            ObjectValue(attribute_name='is_staff', top=0, left=18*cm,
                get_value=lambda instance: instance.is_staff and 'Yes' or 'No'),
        ]

class LandscapeUsersReport(UsersReport):
    """An inheritance report class"""

    title = 'Detailed list of users'
    page_size = landscape(A4)

    class band_page_footer(ReportBand):
        height = 0.5*cm
        elements = [
            Label(text='Created with Geraldo Reports - Landscape', top=0.1*cm),
            SystemField(expression='Printed in %(now:%Y, %b %d)s at %(now:%H:%M)s', top=0.1*cm,
                width=BAND_WIDTH, style={'alignment': TA_RIGHT}),
        ]
        borders = {'top': True}

    def __init__(self, *args, **kwargs):
        super(LandscapeUsersReport, self).__init__(*args, **kwargs)

        self.band_page_header.elements += [
            Label(text="Date joined", top=0.8*cm, left=21*cm),
            ]

        self.band_detail.elements += [
            ObjectValue(attribute_name='date_joined', top=0, left=21*cm),
            ]

Generating PDF...

>>> report = LandscapeUsersReport(queryset=queryset)
>>> report.generate_by(PDFGenerator, filename=os.path.join(cur_dir, 'output/inheritance-landscape-report.pdf'))

The Result