Update architecture documentation (#206)

1 files changed, 35 insertions, 1 deletions

diff --git a/docs/architecture.md b/docs/architecture.md
index 35c3596..51217cc 100644
--- a/docs/architecture.md
+++ b/docs/architecture.md
@@ -1,4 +1,4 @@
-Title: Architecture - Difference between library and D-Bus service
+Title: Architecture of Libproxy
 Slug: Architecture
 
 
@@ -13,3 +13,37 @@ previous versions of Libproxy. To name a few advantages:
 - Automatic documentation out of code
 - Gobject Introspection bindings for almost every programming language
 
+## Plugin types
+
+Libproxy is using internal plugins to extend it's knowledge about different
+configuration options and handling of PAC files. Most of those plugins are
+configuration plugins:
+
+- config-env
+- config-gnome
+- config-kde
+- config-osx
+- config-sysconfig
+- config-windows
+
+Then there is only one pacrunner plugin which handles parsing of JS PAC files:
+
+- pacrunner-duktape
+
+## Configuration plugin priority
+
+Configuration plugins are executed in a specific priority:
+
+- PX_CONFIG_PRIORITY_FIRST (highest)
+- PX_CONFIG_PRIORITY_DEFAULT
+- PX_CONFIG_PRIORITY_LAST (lowest)
+
+Highest priority is used in `config-env` and lowest priority in
+`config-sysconfig`. All the other plugins are running on default priority.
+
+### Configuration plugin enforcement
+
+In case you want to use a specific configuration plugin for a given application,
+you are able to overwrite the priority. Therefore set a environment variable
+`PX_FORCE_CONFIG=config-name` and libproxy will just use this configuration
+plugin.