From 6decdb40bf150d55d87d9c571343d8f590a439d1 Mon Sep 17 00:00:00 2001 From: herm Date: Sun, 5 Feb 2012 12:10:44 -0800 Subject: [PATCH] Updated Filter (markdown) --- Filter.md | 2 ++ 1 file changed, 2 insertions(+) diff --git a/Filter.md b/Filter.md index bdfb6c5..b54c947 100644 --- a/Filter.md +++ b/Filter.md @@ -6,6 +6,7 @@ Each Style-Rule can optionally have a Filter attached. Mapnik walks through all Rules of a Style and checks if it has a Filter specified and if this Filter matches the Object currently rendered. Filters compare an Objects Key-Value Information against the specified rules. When the Datasource is a Postgis Database, the Filter operates on the tables columns, for Shapefiles the Attributes are used. In XML [character entities](http://en.wikipedia.org/wiki/List_of_XML_and_HTML_character_entity_references) are used to construct filters. You can use the following characters to specify value-comparisons: + * Greater Than: `>` * Greater Then or Equal: `>=` * Less Than: `<` @@ -13,6 +14,7 @@ In XML [character entities](http://en.wikipedia.org/wiki/List_of_XML_and_HTML_ch * Equal: `=` Filters can be combined with the following operators: + * A `and` B * A `or` B * `not` A