mygpo/web/templatetags/charts.py

   1 from django import template
   2 from django.utils.safestring import mark_safe
   3 from django.contrib.staticfiles.storage import staticfiles_storage
   4
   5 from mygpo.utils import format_time
   6 from mygpo.publisher.utils import colour_repr
   7
   8
   9 register = template.Library()
  10
  11 @register.simple_tag
  12 def vertical_bar(value, max_value, display=None):
  13     if not max_value:
  14         return ''
  15
  16     if display == 'ratio':
  17         value_str = '%d/%d' % (value, max_value)
  18     else:
  19         value_str = str(value)
  20
  21     ratio = min(float(value) / float(max_value), 1) * 100
  22     if ratio > 40:
  23         left, right = '<span>'+ value_str +'</span>', ''
  24     else:
  25         left, right = '&nbsp;', '<span>'+ value_str +'</span>'
  26     s = '<div class="barbg"><div class="bar" style="width: %.2d%%">%s</div>%s</div>' % (ratio, left, right)
  27     return s
  28
  29 @register.filter
  30 def format_diff(value):
  31     if value > 1:
  32         s = '<img src="%s" title="+%s">' % \
  33             (staticfiles_storage.url('better.png'), value)
  34     elif value < -1:
  35         s = '<img src="%s" title="%s">' % \
  36             (staticfiles_storage.url('worse.png'), value)
  37     else:
  38         s = ''
  39
  40     return mark_safe(s)
  41
  42 @register.filter
  43 def timeline(data):
  44     s = '<script type="text/javascript" src="http://www.google.com/jsapi"></script>\n'
  45     s += '<script type="text/javascript">\n'
  46     s += 'google.load("visualization", "1", {"packages":["annotatedtimeline"]});\n'
  47     s += 'google.setOnLoadCallback(drawChart);\n'
  48     s += 'function drawChart() {\n'
  49     s += 'var data = new google.visualization.DataTable();\n'
  50     s += 'data.addColumn("date", "Date");\n'
  51     s += 'data.addColumn("number", "Listeners");\n'
  52     s += 'data.addColumn("string", "title1");\n'
  53     s += 'data.addColumn("string", "text1");\n'
  54     s += 'data.addRows([\n'
  55
  56     for r in data:
  57         if 'episode' in r and r['episode']:
  58             episode = '"%s"' % r['episode'].title if r['episode'].title else '"Unnamed Episode"'
  59             episode_ = '"released"'
  60         else:
  61             episode = 'undefined'
  62             episode_ = 'undefined'
  63
  64         s += '[new Date(%d, %d, %d), %d, %s, %s],\n' % (r['date'].year, r['date'].month-1, r['date'].day, r['listeners'], episode, episode_)
  65
  66     s += ']);\n'
  67     s += 'var chart = new google.visualization.AnnotatedTimeLine(document.getElementById("chart_div"));\n'
  68     s += 'chart.draw(data, {displayAnnotations: true});\n'
  69     s += '}\n'
  70     s += '</script>\n'
  71
  72     return mark_safe(s)
  73
  74
  75 @register.filter
  76 def pie_chart(parts):
  77     parts = [
  78         'cht=p',
  79         'chs=250x100',
  80         'chl=%s' % '|'.join(parts.iterkeys()),
  81         'chd=t:%s' % ','.join([ repr(x) for x in parts.itervalues() ])
  82         ]
  83
  84     s = '<img src="http://chart.apis.google.com/chart?%s"' % '&'.join(parts)
  85
  86     return mark_safe(s)
  87
  88
  89 @register.filter
  90 def episode_heatmap_visualization(heatmap):
  91     """
  92     display a visual heatmap using the Google Charts API
  93
  94     heatmap_data is expected as an array of numbers of users that have
  95     played this part part of the episode. the length of the parts is
  96     indicated by step_length; the duration of the whole episode is
  97     therefore approximated by len(heatmap_data) * step_length
  98     """
  99     label_steps = 2
 100
 101     max_plays = heatmap.max_plays
 102
 103     if max_plays == 1:
 104         #              light blue       dark blue
 105         colours = ( (198, 217, 253), (77, 137, 249) )
 106     else:
 107         #               red            yellow         green
 108         colours = ( (210, 54, 28), (239, 236, 22), (15, 212, 18) )
 109
 110     WIDTH=760
 111
 112     # maximum number of labels that will be placed on the visualization
 113     MAX_LABELS=20
 114
 115     axis_pos = []
 116     axis_label = []
 117     part_colours = []
 118     widths = []
 119     duration = max(heatmap.borders)
 120
 121     last_label = None
 122     for start, end, plays in heatmap.sections:
 123
 124         if last_label is None or (end-last_label) > (duration/MAX_LABELS):
 125             axis_pos.append(end)
 126             axis_label.append(format_time(end))
 127             last_label = end
 128
 129         rgb = colour_repr(plays, max_plays, colours)
 130         part_colours.append('%02x%02x%02x' % rgb)
 131         widths.append( end-start )
 132
 133     parts = [
 134         'cht=bhs',                            # bar chart
 135         'chco=%s' % ','.join(part_colours),   # colors
 136         'chs=%dx50' % WIDTH,                  # width corresponds to length, arbitrary height
 137         'chds=0,%s' % duration,               # axis scaling from 0 to maximum duration
 138         'chd=t:%s' % '|'.join([repr(w) for w in widths]),  # all block have the same width
 139         'chxt=x',                             # visible axes
 140         'chxr=0,0,%s' % duration,             # axis range for axis 0 (x): 0 - duration
 141         'chxl=0:|%s' % '|'.join(axis_label),  # axis labels
 142         'chxp=0,%s' % ','.join([repr(x) for x in axis_pos]),   # axis label positions
 143         ]
 144
 145     s = '<img src="http://chart.apis.google.com/chart?%s" />' % '&'.join(parts)
 146
 147     return mark_safe(s)
 148
 149
 150
 151 @register.simple_tag
 152 def subscriber_change(change):
 153
 154     if change > 1:
 155         change -= 1
 156         return '+{0:.1%}'.format(change)
 157
 158     # we don't care about negative changes
 159     return ''