pygal/pygal/schedule.py

# -*- coding: utf-8 -*-
import re

from dateutil.parser import parse
from dateutil.relativedelta import relativedelta
from lxml import etree

from pygal.util import (node, grouper, date_range,
                        divide_timedelta_float, TimeScale)
from pygal.graph import Graph

__all__ = ('Schedule')


class Schedule(Graph):
    """
    Graph of temporal scalar data.
    """

    # The format string to be used to format the X axis labels
    x_label_format = '%Y-%m-%d %H:%M:%S'

    # Use this to set the spacing between dates on the axis.  The value
    # must be of the form
    # "\d+ ?((year|month|week|day|hour|minute|second)s?)?"
    # e.g.
    #     graph.timescale_divisions = '2 weeks'
    #     graph.timescale_divisions = '1 month'
    #     graph.timescale_divisions = '3600 seconds'
    #                       easier would be '1 hour'
    timescale_divisions = None

    # The formatting used for the popups.  See x_label_format
    popup_format = '%Y-%m-%d %H:%M:%S'

    _min_x_value = None
    scale_x_divisions = False
    scale_x_integers = False
    bar_gap = True

    stylesheet_names = Graph.stylesheet_names + ['bar.css']

    def add_data(self, data):
        """
        Add data to the plot.
        Note that the data must be in time,value pairs,
        and that the date format
        may be any date that is parseable by ParseDate.
        Also note that, in this example, we're mixing scales; the data from d1
        will probably not be discernable if both data sets are
        plotted on the same graph, since d1 is too granular.
        """
        # The ruby version does something different here, throwing out
        #  any previously added data.
        super(Schedule, self).add_data(data)

    # copied from Bar
    # TODO, refactor this into a common base class (or mix-in)
    def get_bar_gap(self, field_size):
        bar_gap = 10  # default gap
        if field_size < 10:
            # adjust for narrow fields
            bar_gap = field_size / 2
        # the following zero's out the gap if bar_gap is False
        bar_gap = int(self.bar_gap) * bar_gap
        return bar_gap

    def validate_data(self, conf):
        super(Schedule, self).validate_data(conf)
        msg = "Data supplied must be (title, from, to) tripples!"
        assert len(conf['data']) % 3 == 0, msg

    def process_data(self, conf):
        super(Schedule, self).process_data(conf)
        data = conf['data']
        triples = grouper(3, data)

        labels, begin_dates, end_dates = zip(*triples)

        begin_dates = map(self.parse_date, begin_dates)
        end_dates = map(self.parse_date, end_dates)

        # reconstruct the triples in a new order
        reordered_triples = zip(begin_dates, end_dates, labels)

        # because of the reordering, this will sort by begin_date
        #  then end_date, then label.
        reordered_triples.sort()

        conf['data'] = reordered_triples

    def parse_date(self, date_string):
        return parse(date_string)

    def set_min_x_value(self, value):
        if isinstance(value, basestring):
            value = self.parse_date(value)
        self._min_x_value = value

    def get_min_x_value(self):
        return self._min_x_value

    min_x_value = property(get_min_x_value, set_min_x_value)

    def format(self, x, y):
        return x.strftime(self.popup_format)

    def get_x_labels(self):
        format = lambda x: x.strftime(self.x_label_format)
        return map(format, self.get_x_values())

    def y_label_offset(self, height):
        return height / -2.0

    def get_y_labels(self):
        # ruby version uses the last data supplied
        last = -1
        data = self.data[last]['data']
        begin_dates, start_dates, labels = zip(*data)
        return labels

    def draw_data(self):
        bar_gap = self.get_bar_gap(self.get_field_height())

        subbar_height = self.get_field_height() - bar_gap

        x_min, x_max, div = self._x_range()
        x_range = x_max - x_min
        width = (float(self.graph_width) - self.font_size * 2)
        # time_scale
        #scale /= x_range
        scale = TimeScale(width, x_range)

        # ruby version uses the last data supplied
        last = -1
        data = self.data[last]['data']

        for index, (x_start, x_end, label) in enumerate(data):
            count = index + 1  # index is 0-based, count is 1-based
            y = self.graph_height - (self.get_field_height() * count)
            bar_width = scale * (x_end - x_start)
            bar_start = scale * (x_start - x_min)

            node(self.graph, 'rect', {
                'x': bar_start,
                'y': y,
                'width': bar_width,
                'height': subbar_height,
                'class': 'fill%s' % (count + 1),
            })

    def _x_range(self):
        # ruby version uses teh last data supplied
        last = -1
        data = self.data[last]['data']

        start_dates, end_dates, labels = zip(*data)
        all_dates = start_dates + end_dates
        max_value = max(all_dates)
        if not self.min_x_value is None:
            all_dates.append(self.min_x_value)
        min_value = min(all_dates)
        range = max_value - min_value
        right_pad = divide_timedelta_float(
            range, 20.0) or relativedelta(days=10)
        scale_range = (max_value + right_pad) - min_value

        #scale_division = self.scale_x_divisions or (scale_range / 10.0)
        # todo, remove timescale_x_divisions and use scale_x_divisions only
        # but as a time delta
        scale_division = divide_timedelta_float(scale_range, 10.0)

        # this doesn't make sense, because x is a timescale
        #if self.scale_x_integers:
        #    scale_division = min(round(scale_division), 1)

        return min_value, max_value, scale_division

    def get_x_values(self):
        x_min, x_max, scale_division = self._x_range()
        if self.timescale_divisions:
            pattern = re.compile('(\d+) ?(\w+)')
            m = pattern.match(self.timescale_divisions)
            if not m:
                raise (ValueError,
                       "Invalid timescale_divisions: %s" %
                       self.timescale_divisions)

            magnitude = int(m.group(1))
            units = m.group(2)

            parameter = self.lookup_relativedelta_parameter(units)

            delta = relativedelta(**{parameter: magnitude})

            scale_division = delta

        return date_range(x_min, x_max, scale_division)

    def lookup_relativedelta_parameter(self, unit_string):
        from util import reverse_mapping, flatten_mapping
        unit_string = unit_string.lower()
        mapping = dict(
            years=('years', 'year', 'yrs', 'yr'),
            months=('months', 'month', 'mo'),
            weeks=('weeks', 'week', 'wks', 'wk'),
            days=('days', 'day'),
            hours=('hours', 'hour', 'hr', 'hrs', 'h'),
            minutes=('minutes', 'minute', 'min', 'mins', 'm'),
            seconds=('seconds', 'second', 'sec', 'secs', 's'),
        )
        mapping = reverse_mapping(mapping)
        mapping = flatten_mapping(mapping)
        if not unit_string in mapping:
            raise ValueError("%s doesn't match any supported time/date unit")
        return mapping[unit_string]