1 files changed, 38 insertions, 1 deletions
diff --git a/acf/model/root.lua b/acf/model/root.lua
index f0f21c1..f273c4a 100644
--- a/acf/model/root.lua
+++ b/acf/model/root.lua
@@ -5,11 +5,14 @@ See LICENSE file for license details
 
 module(..., package.seeall)
 
-local node = require('acf.model.node')
 local model = require('acf.model.model')
+local node = require('acf.model.node')
 local object = require('acf.object')
 local pth = require('acf.path')
 
+local util = require('acf.util')
+local setdefault = util.setdefault
+
 
 RootModel = model.new()
 
@@ -27,7 +30,41 @@ function RootModel:meta(path)
    return node.mmeta(self:search(pth.parent(path), true), pth.name(path))
 end
 
+
+local _topology = {}
+
+function topology(addr, create)
+   local top = _topology
+   if type(addr) == 'table' then addr = util.copy(addr)
+   else addr = pth.split(addr) end
+
+   local function defaults(top)
+      return util.setdefaults(top, {members={}, paths={}})
+   end
+
+   while #addr > 0 do
+      if create then
+	 top = setdefault(defaults(top).members, addr[1], {})
+      else
+	 top = top.members[addr[1]] or top.members[pth.wildcard]
+	 if not top then return end
+      end
+      table.remove(addr, 1)
+   end
+
+   return defaults(top)
+end
+
 function register(name, field, params)
    params.create = true
    RootModel[name] = model.to_field(field, params)
+
+   _topology = {}
+
+   -- TODO optimize: do not traverse already registered models
+   for i, record in ipairs(node.topology(RootModel())) do
+      local top = topology(record.addr, true)
+      setdefault(top, 'order', i)
+      table.insert(top.paths, record.path)
+   end
 end