improved handling of nested transactions

add nested transaction support to protocol
allow deferring validation to parent transaction
process each update request within a nested transaction

2 files changed, 18 insertions, 18 deletions

diff --git a/acf/model/model.lua b/acf/model/model.lua
index 6a9a843..aa27312 100644
--- a/acf/model/model.lua
+++ b/acf/model/model.lua
@@ -79,6 +79,13 @@ function Model:init(txn, path, addr)
       return util.map(function(f) return f.name end, mt.meta.fields)
    end
 
+   function mt.validate()
+      for _, name in ipairs(mt.members()) do
+	 local field = mt.field(name)
+	 if not field.compute then field:validate_saved() end
+      end
+   end
+
    function mt.__index(t, k)
       local f = mt.field(k)
       if f then
@@ -93,14 +100,4 @@ function Model:init(txn, path, addr)
       if not f then raise(mt.path, 'Field named '..k..' does not exist') end
       f:save(v)
    end
-
-   txn.validate[mt.path] = function() self:validate() end
-end
-
-function Model:validate()
-   local mt = getmetatable(self)
-   for _, name in ipairs(mt.members()) do
-      local field = mt.field(name)
-      if not field.compute then field:validate_saved() end
-   end
 end
diff --git a/acf/model/node.lua b/acf/model/node.lua
index 3459fce..f893d6a 100644
--- a/acf/model/node.lua
+++ b/acf/model/node.lua
@@ -48,6 +48,8 @@ function TreeNode:init(txn, path, addr)
    mt.txn = txn
    mt.path = path
    mt.addr = addr
+
+   txn.validable[path] = true
 end
 
 function TreeNode:search(path)
@@ -67,14 +69,6 @@ Collection = class(TreeNode)
 function Collection:init(txn, path, addr, field, required)
    super(self, Collection):init(txn, path, addr)
 
-   if required then
-      txn.validate[path] = function()
-			      if #txn:get(addr) == 0 then
-				 raise(path, 'Collection cannot be empty')
-			      end
-			   end
-   end
-
    self.init = nil
    self.search = nil
 
@@ -84,6 +78,14 @@ function Collection:init(txn, path, addr, field, required)
    mt.meta = {type='collection', members=mt.field:meta('$')}
    function mt.mmeta(name) return mt.meta.members end
    function mt.members() return txn:get(addr) or {} end
+
+   function mt.validate()
+      if required then
+	 if #txn:get(addr) == 0 then
+	    raise(path, 'Collection cannot be empty')
+	 end
+      end
+   end
    
    function mt.__index(t, k) return mt.field:load(k) end
    function mt.__newindex(t, k, v) mt.field:save(k, v) end
@@ -132,3 +134,4 @@ members = meta_func('members')
 meta = meta_func('meta')
 mmeta = meta_func('mmeta')
 path = meta_func('path')
+validate = meta_func('validate')