mygpo/web/templatetags/charts.py

   1 from django import template
   2 from django.utils.safestring import mark_safe
   3
   4 from mygpo.utils import format_time
   5 from mygpo.publisher.utils import colour_repr
   6
   7
   8 register = template.Library()
   9
  10 @register.simple_tag
  11 def vertical_bar(value, max_value, display=None):
  12     if not max_value:
  13         return ''
  14
  15     if display == 'ratio':
  16         value_str = '%d/%d' % (value, max_value)
  17     else:
  18         value_str = str(value)
  19
  20     ratio = min(float(value) / float(max_value), 1) * 100
  21     if ratio > 40:
  22         left, right = '<span>'+ value_str +'</span>', ''
  23     else:
  24         left, right = '&nbsp;', '<span>'+ value_str +'</span>'
  25     s = '<div class="barbg"><div class="bar" style="width: %.2d%%">%s</div>%s</div>' % (ratio, left, right)
  26     return s
  27
  28 @register.filter
  29 def format_diff(value):
  30     if value > 1:
  31         s = '<img src="/media/better.png" title="+%s">' % value
  32     elif value < -1:
  33         s = '<img src="/media/worse.png" title="%s">' % value
  34     else:
  35         s = ''
  36
  37     return mark_safe(s)
  38
  39 @register.filter
  40 def timeline(data):
  41     s = '<script type="text/javascript" src="http://www.google.com/jsapi"></script>\n'
  42     s += '<script type="text/javascript">\n'
  43     s += 'google.load("visualization", "1", {"packages":["annotatedtimeline"]});\n'
  44     s += 'google.setOnLoadCallback(drawChart);\n'
  45     s += 'function drawChart() {\n'
  46     s += 'var data = new google.visualization.DataTable();\n'
  47     s += 'data.addColumn("date", "Date");\n'
  48     s += 'data.addColumn("number", "Listeners");\n'
  49     s += 'data.addColumn("string", "title1");\n'
  50     s += 'data.addColumn("string", "text1");\n'
  51     s += 'data.addRows([\n'
  52
  53     for r in data:
  54         if 'episode' in r and r['episode']:
  55             episode = '"%s"' % r['episode'].title if r['episode'].title else '"Unnamed Episode"'
  56             episode_ = '"released"'
  57         else:
  58             episode = 'undefined'
  59             episode_ = 'undefined'
  60
  61         s += '[new Date(%d, %d, %d), %d, %s, %s],\n' % (r['date'].year, r['date'].month-1, r['date'].day, r['listeners'], episode, episode_)
  62
  63     s += ']);\n'
  64     s += 'var chart = new google.visualization.AnnotatedTimeLine(document.getElementById("chart_div"));\n'
  65     s += 'chart.draw(data, {displayAnnotations: true});\n'
  66     s += '}\n'
  67     s += '</script>\n'
  68
  69     return mark_safe(s)
  70
  71
  72 @register.filter
  73 def pie_chart(parts):
  74     parts = [
  75         'cht=p',
  76         'chs=250x100',
  77         'chl=%s' % '|'.join(parts.iterkeys()),
  78         'chd=t:%s' % ','.join([ repr(x) for x in parts.itervalues() ])
  79         ]
  80
  81     s = '<img src="http://chart.apis.google.com/chart?%s"' % '&'.join(parts)
  82
  83     return mark_safe(s)
  84
  85
  86 @register.filter
  87 def episode_heatmap_visualization(heatmap):
  88     """
  89     display a visual heatmap using the Google Charts API
  90
  91     heatmap_data is expected as an array of numbers of users that have
  92     played this part part of the episode. the length of the parts is
  93     indicated by step_length; the duration of the whole episode is
  94     therefore approximated by len(heatmap_data) * step_length
  95     """
  96     label_steps = 2
  97
  98     max_plays = heatmap.max_plays
  99
 100     if max_plays == 1:
 101         #              light blue       dark blue
 102         colours = ( (198, 217, 253), (77, 137, 249) )
 103     else:
 104         #               red            yellow         green
 105         colours = ( (210, 54, 28), (239, 236, 22), (15, 212, 18) )
 106
 107     WIDTH=760
 108
 109     # maximum number of labels that will be placed on the visualization
 110     MAX_LABELS=20
 111
 112     axis_pos = []
 113     axis_label = []
 114     part_colours = []
 115     widths = []
 116     duration = max(heatmap.borders)
 117
 118     last_label = None
 119     for start, end, plays in heatmap.sections:
 120
 121         if last_label is None or (end-last_label) > (duration/MAX_LABELS):
 122             axis_pos.append(end)
 123             axis_label.append(format_time(end))
 124             last_label = end
 125
 126         rgb = colour_repr(plays, max_plays, colours)
 127         part_colours.append('%02x%02x%02x' % rgb)
 128         widths.append( end-start )
 129
 130     parts = [
 131         'cht=bhs',                            # bar chart
 132         'chco=%s' % ','.join(part_colours),   # colors
 133         'chs=%dx50' % WIDTH,                  # width corresponds to length, arbitrary height
 134         'chds=0,%s' % duration,               # axis scaling from 0 to maximum duration
 135         'chd=t:%s' % '|'.join([repr(w) for w in widths]),  # all block have the same width
 136         'chxt=x',                             # visible axes
 137         'chxr=0,0,%s' % duration,             # axis range for axis 0 (x): 0 - duration
 138         'chxl=0:|%s' % '|'.join(axis_label),  # axis labels
 139         'chxp=0,%s' % ','.join([repr(x) for x in axis_pos]),   # axis label positions
 140         ]
 141
 142     s = '<img src="http://chart.apis.google.com/chart?%s" />' % '&'.join(parts)
 143
 144     return mark_safe(s)
 145
 146
 147
 148 @register.simple_tag
 149 def subscriber_change(change):
 150
 151     if change > 1:
 152         change -= 1
 153         return '+{0:.1%}'.format(change)
 154
 155     # we don't care about negative changes
 156     return ''