Chart data files (#3130)

ralsina · web-flow · commit 69ef41d1ca94 · 2018-08-06T11:19:55.000-03:00
Fix #3129 by providing support for JSON/YAML files in chart shortcodes and directives
diff --git a/CHANGES.txt b/CHANGES.txt
@@ -6,6 +6,7 @@ Changes since Beta 2
 Features
 --------
 
+* New data_file option for chart shortcode and directive (Issue #3129)
 * Show the filename of the missing file when ``nikola serve`` can't
   find a file (i.e. when an 404 error occurs).
 * Better error messages for JSON download failures in ``nikola
diff --git a/docs/manual.rst b/docs/manual.rst
@@ -1256,14 +1256,39 @@ chart
 
     .. code:: text
 
-        {{% raw %}}{{% chart Bar title='Browser usage evolution (in %)' %}}
-        x_labels='["2002","2003","2004","2005","2006","2007","2008","2009","2010","2011","2012"]'%}}
+        {{% raw %}}{{% chart Bar title='Browser usage evolution (in %)'
+x_labels='["2002","2003","2004","2005","2006","2007"]' %}}
         'Firefox', [None, None, 0, 16.6, 25, 31]
         'Chrome',  [None, None, None, None, None, None]
         'IE',      [85.8, 84.6, 84.7, 74.5, 66, 58.6]
         'Others',  [14.2, 15.4, 15.3, 8.9, 9, 10.4]
         {{% /chart %}}{{% /raw %}}
 
+    Additionally, you can use a file_data argument which can point to a JSON or YAML file, and will be used for both arguments and data.
+    Example:
+
+    .. code:: json
+
+        {
+            "x_labels": ["2002","2003","2004","2005","2006","2007"],
+            "data": {
+                "Firefox": [null, null, 0, 16.6, 25, 31],
+                "Chrome": [null, null, null, null, null, null],
+                "IE": [85.8, 84.6, 84.7, 74.5, 66, 58.6],
+                "Others": [14.2, 15.4, 15.3, 8.9, 9, 10.4]
+            }
+        }
+
+    Which can be used like this:
+
+    .. code:: text
+
+        {{% raw %}}{{% chart Bar title='Browser usage evolution (in %)' data_file="posts/browsers.json" %}}
+        {{% /chart %}}
+        {{% /raw %}}
+
+    If the data or any option is available in both the ``data_file`` and the document, the document has priority.
+
 doc
     Will link to a document in the page, see `Doc role for details
     <#doc>`__. Example:
@@ -2663,6 +2688,8 @@ You can use any option described in `the pygal docs <http://pygal.org/en/stable/
 Finally, the content of the directive is the actual data, in the form of a label and
 a list of values, one series per line.
 
+You can also specify a ``:data_file:`` option as described in the documentation for the chart shortcut.
+
 Doc
 ~~~
 
diff --git a/nikola/plugins/compile/rest/chart.py b/nikola/plugins/compile/rest/chart.py
@@ -72,6 +72,7 @@ class Chart(Directive):
         "classes": directives.unchanged,
         "css": directives.unchanged,
         "defs": directives.unchanged,
+        "data_file": directives.unchanged,
         "disable_xml_declaration": directives.unchanged,
         "dots_size": directives.unchanged,
         "dynamic_print_values": directives.unchanged,
diff --git a/nikola/plugins/shortcode/chart.py b/nikola/plugins/shortcode/chart.py
@@ -33,7 +33,7 @@
     pygal = None  # NOQA
 
 from nikola.plugin_categories import ShortcodePlugin
-from nikola.utils import req_missing
+from nikola.utils import req_missing, load_data
 
 _site = None
 
@@ -50,18 +50,30 @@ def handler(self, chart_type, **_options):
                 ['pygal'], 'use the Chart directive', optional=True)
             return '<div class="text-error">{0}</div>'.format(msg)
         options = {}
-        data = _options.pop('data')
+        chart_data = []
         _options.pop('post', None)
         _options.pop('site')
-        if 'style' in _options:
-            style_name = _options.pop('style')
-        else:
-            style_name = 'BlueStyle'
+        data = _options.pop('data')
+
+        for line in data.splitlines():
+            line = line.strip()
+            if line:
+                chart_data.append(literal_eval('({0})'.format(line)))
+        if 'data_file' in _options:
+            options = load_data(_options['data_file'])
+            _options.pop('data_file')
+            if not chart_data:  # If there is data in the document, it wins
+                for k, v in options.pop('data', {}).items():
+                    chart_data.append((k, v))
+
+        options.update(_options)
+
+        style_name = options.pop('style', 'BlueStyle')
         if '(' in style_name:  # Parametric style
             style = eval('pygal.style.' + style_name)
         else:
             style = getattr(pygal.style, style_name)
-        for k, v in _options.items():
+        for k, v in options.items():
             try:
                 options[k] = literal_eval(v)
             except Exception:
@@ -73,9 +85,6 @@ def handler(self, chart_type, **_options):
         if _site and _site.invariant:
             chart.no_prefix = True
         chart.config(**options)
-        for line in data.splitlines():
-            line = line.strip()
-            if line:
-                label, series = literal_eval('({0})'.format(line))
-                chart.add(label, series)
+        for label, series in chart_data:
+            chart.add(label, series)
         return chart.render().decode('utf8')
