Charts with CairoPlot
=====================

This test is done with a chart generated by CairoPlot. You can find it here:

    http://linil.wordpress.com/2008/09/16/cairoplot-11/

Charts are another important thing in reports. Geraldo is compatible with every
charting library if it has a way to render the chart as a common image format,
like JPG, PNG, GIF, etc::

    import os
    cur_dir = os.path.dirname(os.path.abspath(__file__))
    
    import Image as PILImage
    from CairoPlot import pie_plot, bar_plot
    
    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_JUSTIFY, TA_RIGHT
    from reportlab.lib.colors import navy, yellow, red, white
    
    from geraldo import Report, ReportBand, Label, ObjectValue, SystemField,\
        SubReport, FIELD_ACTION_COUNT, FIELD_ACTION_AVG, FIELD_ACTION_MIN,\
        FIELD_ACTION_MAX, FIELD_ACTION_SUM, FIELD_ACTION_DISTINCT_COUNT,\
        BAND_WIDTH, Rect, Line, Image
    
    def get_chart_for_user(graphic):
        """Method to get chart"""
        data = [dic['id'] for dic in graphic.instance.user_permissions.values('id')]
    
        if not data:
            return None
    
        filename = os.path.join(cur_dir, 'output/user-chart-%d.png'%graphic.instance.id)
    
        bar_plot(filename, data, 400, 300, border = 20, grid = True, rounded_corners = True)
    
        return PILImage.open(filename)
    
    class UsersReport(Report):
        title = 'Using chart from CairoPlot'
        borders = {'all': True}
        default_style = {'fontName': 'Helvetica'}
    
        class band_summary(ReportBand):
            height = 5*cm
            elements = [
                Label(text="Users count:", top=0.1*cm, left=0.2*cm),
                ObjectValue(attribute_name='username', top=0.1*cm, left=4*cm,\
                    action=FIELD_ACTION_COUNT, display_format='%s permissions found'),
    
                Label(text="Users ids average:", top=0.6*cm, left=0.2*cm),
                ObjectValue(attribute_name='id', top=0.6*cm, left=4*cm, action=FIELD_ACTION_AVG),
    
                Label(text="Users ids minimum:", top=1.1*cm, left=0.2*cm),
                ObjectValue(attribute_name='id', top=1.1*cm, left=4*cm, action=FIELD_ACTION_MIN),
    
                Label(text="Users ids maximum:", top=1.6*cm, left=0.2*cm),
                ObjectValue(attribute_name='id', top=1.6*cm, left=4*cm, action=FIELD_ACTION_MAX),
    
                Label(text="Users ids sum:", top=2.1*cm, left=0.2*cm),
                ObjectValue(attribute_name='id', top=2.1*cm, left=4*cm, action=FIELD_ACTION_SUM),
    
                Label(text="Users first name distinct:", top=2.6*cm, left=0.2*cm),
                ObjectValue(attribute_name='first_name', top=2.6*cm, left=4*cm, action=FIELD_ACTION_DISTINCT_COUNT),
    
                Image(filename=os.path.join(cur_dir, 'output/cairoplot.png'), left=11*cm, top=0.2*cm)
            ]
            borders = {'top': True}
    
        class band_page_footer(ReportBand):
            height = 1*cm
            elements = [
                Label(text='Created with Geraldo Reports', top=0, left=0.5*cm),
                SystemField(expression='Printed in %(now:%Y, %b %d)s at %(now:%H:%M)s  ', top=0,
                    width=BAND_WIDTH, style={'alignment': TA_RIGHT, 'rightIndent': 0.5*cm}),
            ]
    
        class band_detail(ReportBand):
            height = 8.5*cm
            force_new_page = True
            elements = [
                # check why BAND_WIDTH doesn't work XXX
                Rect(width=BAND_WIDTH, height=1.6*cm, left=0, top=0, fill_color=yellow, fill=True, _test_temp=True),
                ObjectValue(attribute_name='username', width=BAND_WIDTH, left=0.4*cm, top=0.4*cm,
                    get_value=lambda instance: instance.get_full_name().strip() or instance.username,
                    style={'fontName': 'Helvetica-Bold', 'fontSize': 16, 'textColor': navy}),
                Image(left=0.5*cm, top=2*cm,
                    get_image=lambda graphic: PILImage.open(os.path.join(cur_dir, '%d.jpg'%graphic.instance.id))),
    
                Label(text='First name:', top=2*cm, left=5*cm),
                ObjectValue(attribute_name='first_name', width=BAND_WIDTH, top=2*cm, left=7*cm),
    
                Label(text='Last name:', top=2.5*cm, left=5*cm),
                ObjectValue(attribute_name='last_name', width=BAND_WIDTH, top=2.5*cm, left=7*cm),
    
                Label(text='Username:', top=3*cm, left=5*cm),
                ObjectValue(attribute_name='username', width=BAND_WIDTH, top=3*cm, left=7*cm),
    
                Image(left=10.5*cm, top=2*cm, get_image=get_chart_for_user),
            ]
            borders = {'bottom': True}
            child_bands = [
                ReportBand(
                    default_style={'textColor': white, 'fontName': 'Helvetica-Bold'},
                    height = 0.6*cm,
                    elements = [
                        Rect(left=0, top=0, width=BAND_WIDTH, height=0.6*cm,
                            fill_color=navy, fill=True, _test_temp=True),
                        Label(text="ID", top=0.1*cm, left=0.5*cm),
                        Label(text="Permission", top=0.1*cm, left=4*cm),
                    ],
                    borders={'bottom': True}),
                ]
    
        subreports = [
            SubReport(
                queryset_string = '%(object)s.user_permissions.all()',
                band_detail = ReportBand(
                        default_style={'fontName': 'Helvetica'},
                        height=0.5*cm,
                        elements=[
                            ObjectValue(attribute_name='id', top=0, left=0.5*cm),
                            ObjectValue(attribute_name='name', top=0, left=4*cm),
                        ],
                        borders={'bottom': True},
                    ),
            ),
        ]

Instantiating the report...

    >>> queryset = User.objects.all().order_by('-id')
    >>> report = UsersReport(queryset=queryset)
    >>> from geraldo.generators import PDFGenerator

Building the chart

    >>> data = dict([(user['username'], user['id']) for user in report.queryset.values('id', 'username')])
    >>> pie_plot(os.path.join(cur_dir, 'output/cairoplot.png'), data, 350, 200)

PDF generation

    >>> report.generate_by(PDFGenerator, filename=os.path.join(cur_dir, 'output/charts-cairoplot-report.pdf'))

The Result

- http://geraldo.svn.sourceforge.net/viewvc/geraldo/examples/charts-cairoplot-report.pdf

