Made documentation of config.assets.precompile slightly more explicit.

Having read the previous version of the documentation, I was surprised
when a wildcarded CSS pattern in precompile picked up a whole load of
SCSS files!  I've amended lines 426 onwards to document the behaviour.

1 files changed, 3 insertions, 1 deletions

diff --git a/railties/guides/source/asset_pipeline.textile b/railties/guides/source/asset_pipeline.textile
index bec1fc909e..9ba2e235bc 100644
--- a/railties/guides/source/asset_pipeline.textile
+++ b/railties/guides/source/asset_pipeline.textile
@@ -423,12 +423,14 @@ It is important that this folder is shared between deployments so that remotely
 
 NOTE. If you are precompiling your assets locally, you can use +bundle install --without assets+ on the server to avoid installing the assets gems (the gems in the assets group in the Gemfile).
 
-The default matcher for compiling files includes +application.js+, +application.css+ and all non-JS/CSS files (i.e., +.coffee+ and +.scss+ files are *not* automatically included as they compile to JS/CSS):
+The default matcher for compiling files includes +application.js+, +application.css+ and all non-JS/CSS files (this will include all image assets automatically):
 
 <ruby>
 [ Proc.new{ |path| !File.extname(path).in?(['.js', '.css']) }, /application.(css|js)$/ ]
 </ruby>
 
+NB: the matcher (and other members of the precompile array; see below) is applied to the final compiled file name.  This means that anything that compiles to JS/CSS is excluded, as well as raw JS/CSS files; for example, +.coffee+ and +.scss+ files are *not* automatically included as they compile to JS/CSS.
+
 If you have other manifests or individual stylesheets and JavaScript files to include, you can add them to the +precompile+ array:
 
 <erb>