Issue 4687 - Add Context Function get_pages_metadata to Test Site

tests/test_site/globals/get_pages_metadata.py

+import re
+from jinja2 import contextfunction
+
+
+@contextfunction
+def get_pages_metadata(context, filters=None):
+    if not isinstance(filters, dict) and filters:
+        raise TypeError('Filters are not a dictionary')
+
+    return_data = []
+    for page_name, _format in context['source'].list_pages():
+        data, filename = context['source'].read_page(page_name, _format)
+        page_data = parse_page_metadata(data, page_name)
+
+        if filter_metadata(filters, page_data, page_name) is True:
+            return_data.append(page_data)
+
+    return return_data
+
+
+def parse_page_metadata(data, page):
+    page_metadata = {}
+    lines = data.splitlines(True)
+    for i, line in enumerate(lines):
+        if not re.search(r'^\s*[\w\-]+\s*=', line):
+            break
+        name, value = line.split('=', 1)
+        value = tuple(value.strip().split(','))
+        page_metadata[name.strip()] = value
+        page_metadata['page'] = page

[Vasily Kuznetsov, 2017/01/12 10:37:47]

I don't think we want to execute this for each line. It seems better to start
with {'page': page} on line 22 instead.

[Jon Sonesen, 2017/01/19 07:51:40]

Done.

+    return page_metadata
+
+
+def filter_metadata(filters, metadata, page):
+    if filters is None:
+        return True
+    for filter_name, filter_value in filters.items():
+        if filter_name not in metadata[page]:

[Vasily Kuznetsov, 2017/01/12 10:37:47]

This change looks like a mistake. `metadata` is already the metadata of the page
so doing the `[page]` part is not necessary (actually it leads to an error).

[Jon Sonesen, 2017/01/19 07:51:40]

Yeah, was a fail. Will fix

+            return False
+        for option in filter_value.split(','):
+            if option not in metadata[page][filter_name]:

[Vasily Kuznetsov, 2017/01/12 10:37:47]

Same here regarding the `[page]` part. Also, what if the metadata doesn't
contain `filter_name`?

[Jon Sonesen, 2017/01/19 07:51:40]

You are right

+                return False
+    return True