From ada26f8869e275f2b3f87ab3c7d60915527f4ac3 Mon Sep 17 00:00:00 2001 From: gisupc Date: Mon, 10 Dec 2012 04:03:40 -0800 Subject: [PATCH] Updated Expression (markdown) --- Expression.md | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/Expression.md b/Expression.md index aaf0031..eb29533 100644 --- a/Expression.md +++ b/Expression.md @@ -3,3 +3,7 @@ Mapnik Expressions enable data-driven behavior in Mapnik. They are constructed f Recently, in Mapnik 2.1, expressions became enabled in the `transform` parser used to apply affine transformations to image and svg symbols. So, now you can not only, for example, rotate symbols with a transform like `transform="rotate(45)"` but the rotation can be data driven like `transform="rotate([field])"` For more info on the original design see: http://mapnik.org/news/2009/12/08/future_mapnik2/ + +in the feature,I think the color attribute such as the stroke of +LineSymbolizer, the fill of PolygonSymbolizer, the fill of TextSymbolizer and so on, should also support Expression, this is more useful. +