Add example for aggregate collect functions

fix #24962
qgis · Aug 31, 2020 · fc1f3bf · fc1f3bf
1 parent 7c6ce37
commit fc1f3bf
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Showing 2 changed files with 4 additions and 2 deletions.
diff --git a/resources/function_help/json/aggregate b/resources/function_help/json/aggregate
@@ -17,6 +17,7 @@
 	{ "expression":"aggregate(layer:='rail_stations',aggregate:='sum',expression:=\"passengers\",filter:=\"class\">3)", "returns":"sums up all values from the \"passengers\" field from features where the \"class\" attribute is greater than 3 only"},
 	{ "expression":"aggregate(layer:='rail_stations',aggregate:='concatenate', expression:=\"name\", concatenator:=',')", "returns":"comma separated list of the name field for all features in the rail_stations layer"},
 	{ "expression":"aggregate(layer:='countries', aggregate:='max', expression:=\"code\", filter:=intersects( $geometry, geometry(@parent) ) )", "returns":"The country code of an intersecting country on the layer 'countries'"},
-	{ "expression":"aggregate(layer:='rail_stations',aggregate:='sum',expression:=\"passengers\",filter:=contains( @atlas_geometry, $geometry ) )", "returns":"sum of all values from the passengers field in the rail_stations within the current atlas feature"}
+	{ "expression":"aggregate(layer:='rail_stations',aggregate:='sum',expression:=\"passengers\",filter:=contains( @atlas_geometry, $geometry ) )", "returns":"sum of all values from the passengers field in the rail_stations within the current atlas feature"},
+	{ "expression":"aggregate(layer:='rail_stations', aggregate:='collect', expression:=centroid($geometry), filter:=\"region_name\" = attribute(@parent,'name') )", "returns":"aggregates centroid geometries of the rail_stations of the same region as current feature"}
 	]
 }
diff --git a/resources/function_help/json/collect b/resources/function_help/json/collect
@@ -9,6 +9,7 @@
 	{"arg":"filter", "optional":true, "description":"optional expression to use to filter features used to calculate aggregate"}
   ],
   "examples": [
-	{ "expression":"collect( $geometry )", "returns":"multipart geometry of aggregated geometries"}
+	{ "expression":"collect( $geometry )", "returns":"multipart geometry of aggregated geometries"},
+	{ "expression":"collect( centroid($geometry), group_by:=\"region\", filter:= \"use\" = 'civilian' )", "returns":"aggregated centroids of the civilian features based on their region value"}
   ]
 }