Ability to group products by regex name on match

Author: benjaminleighton

README.md

@@ -129,6 +129,12 @@ You can alter default [Flask](http://flask.pocoo.org/docs/1.0/config/) or
     # Default product to display (picks first available)
     CUBEDASH_DEFAULT_PRODUCTS = ('ls8_nbar_albers', 'ls7_nbar_albers')
 
+    # Limited regex syntax and group name pairs. Within pairs regex and group name seperated by 
+    # pairs seperated by ; regex matches on product name
+    # eg ".*albers.*,Albers projection;.*level1.*,Level 1 products" defaults to None
+    # items are only categorized into the first group matched even if subsequent regexes match
+    # if defined overrules CUBEDASH_PRODUCT_GROUP_BY_FIELD 
+    CUBEDASH_PRODUCT_GROUP_BY_REGEX = ".*albers.*,Albers projection;.*level1.*,Level 1 products"
     # Which field should we use when grouping products in the top menu?
     CUBEDASH_PRODUCT_GROUP_BY_FIELD = 'product_type'
     # Ungrouped products will be grouped together in this size.

cubedash/_pages.py

@@ -1,6 +1,7 @@
 import itertools
 from datetime import datetime, timedelta
 from typing import List, Tuple
+import re
 
 import cubedash
 import datacube
@@ -275,10 +276,30 @@ def _get_grouped_products() -> List[Tuple[str, List[ProductWithSummary]]]:
     # Which field should we use when grouping products in the top menu?
     group_by_field = app.config.get("CUBEDASH_PRODUCT_GROUP_BY_FIELD", "product_type")
     group_field_size = app.config.get("CUBEDASH_PRODUCT_GROUP_SIZE", 5)
-
-    # Group using the configured key, or fall back to the product name.
-    def key(t):
-        return t[0].fields.get(group_by_field) or t[0].name
+    group_by_regex = app.config.get("CUBEDASH_PRODUCT_GROUP_BY_REGEX", None)
+
+    if group_by_regex:
+        grouped_summaries = {}
+        grouped_product_summarise =[]
+        group_regex = {}
+        regex_group_pairs = group_by_regex.split(';')
+        for regex_group_pair in regex_group_pairs:
+            regex, group = regex_group_pair.split(',')
+            group_regex[group] = re.compile(regex)  
+            grouped_summaries[group] = []
+        # group using regex 
+        def regex_key(t):
+            for product_summary in product_summaries:
+                for group, regex in group_regex.items():
+                    if regex.match(t[0].name):
+                        return group
+            return t[0].name
+        key = regex_key
+    else:
+        # Group using the configured key, or fall back to the product name.
+        def field_key(t):
+            return t[0].fields.get(group_by_field) or t[0].name
+        key = field_key
 
     grouped_product_summarise = sorted(
         (