Using Events SystemΒΆ

This example uses events to make customizations and also print messages while is printing:

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

from geraldo.utils import A4, cm, TA_CENTER, TA_RIGHT

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

def element_before_print(self, generator):
    """Element with before print event - hides if the text is 'New York'"""
    self.visible = self.text != 'New York'

def element_after_print(self, generator):
    """Element with after print event, that works"""
    print 'After print city %s'%self.text

class SimpleListReport(Report):
    title = 'Demonstration without Django'

    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="Name", top=0.8*cm, left=3*cm),
        ]
        borders = {'bottom': True}

    class band_page_footer(ReportBand):
        height = 0.5*cm
        elements = [
            Label(text='Created with Geraldo Reports', top=0.1*cm, left=0),
            SystemField(expression='Page # %(page_number)d of %(page_count)d', top=0.1*cm,
                width=BAND_WIDTH, style={'alignment': TA_RIGHT}),
        ]
        borders = {'top': True}

    class band_detail(ReportBand):
        height = 0.5*cm
        elements = [
            ObjectValue(attribute_name='id', top=0, left=0,),
            ObjectValue(attribute_name='name', top=0, left=3*cm,
                # Element with before print event - hides if the text is 'New York'
                before_print=element_before_print,

                #Element with after print event, that works
                after_print=element_after_print,
                )
        ]

    # Report events overring methods

    def do_before_print(self, generator):
        """Report before print event"""
        self.title = '%s - %s objects'%(self.title, len(objects_list))

    def do_before_generate(self, generator):
        """Report before generate event"""
        print 'Starting generating!'

    def do_after_print(self, generator):
        """Report after print event"""
        print 'Printing finished!'

    def do_on_new_page(self, page, page_number, generator):
        """Report on new page event"""
        print 'Printing page # %s!'%page_number

Important: if you are setting events as methods, you must name them as “do_” plus event name (i.e. do_before_print). Otherwise, if you are setting them as attributes (setting when creating objects or setting them dinamically) you must name them without “do_”, just their names (i.e. before_print).

Executing for a list of objects (list of cities)...

>>> class MyObject(object):
...     def __init__(self, **kwargs):
...         for k,v in kwargs.items():
...             setattr(self, k, v)
>>> objects_list = [
...     MyObject(id=1, name='Rio de Janeiro'),
...     MyObject(id=2, name='New York'),
...     MyObject(id=3, name='Paris'),
...     MyObject(id=4, name='London'),
...     MyObject(id=5, name='Tokyo'),
...     MyObject(id=6, name='Moscow'),
...     MyObject(id=7, name='Beijing'),
...     MyObject(id=8, name='Hamburg'),
...     MyObject(id=9, name='New Delhi'),
...     MyObject(id=10, name='Jakarta'),
... ]
>>> report = SimpleListReport(queryset=objects_list)

PDF generation

>>> from geraldo.generators import PDFGenerator
>>> report.generate_by(PDFGenerator, filename=os.path.join(cur_dir, 'output/generated-with-events.pdf'))