Change field loop node "current field" to a stack to enable fugure support for nested GROUPS.

Author: SteveIves

CodeGenEngine/CodeGenContext.dbl

@@ -70,26 +70,21 @@ namespace CodeGen.Engine
 .region "Task Context"
 
         public readwrite property ExtendedRepositoryProperties, @Dictionary<string, Dictionary<string, object>>, new Dictionary<string, Dictionary<string, Object>>()
+
         ;;Main repository context
         public readwrite property Properties,               @ConcurrentDictionary<Object, Object>, new ConcurrentDictionary<Object, Object>()
+
         ;;; <summary>
         ;;; Exposes the structures BEING PROCESSED to the parser environment
         ;;; </summary>
         public readwrite property Structures,               @RpsStructureCollection
+
         ;;; <summary>
         ;;; Exposes the full repository to the parser environment
         ;;; </summary>
         public readwrite property Repository,               @Repository
 
-        ;;; <summary>
-        ;;; Current repository structure in use
-        ;;; </summary>
-        public property CurrentStructure, @Stack<RpsStructure>
-            method get
-            proc
-                mreturn mCurrentStructure
-            end
-        endproperty
+        ;; Access to the current structure is only via various public methods (below)
         private mCurrentStructure, @Stack<RpsStructure>
 
         ;;Other context

CodeGenEngine/ExpressionEvaluators/ExpressionEvaluatorFieldLoop.dbl

@@ -293,7 +293,7 @@ namespace CodeGen.Engine
             begin
                 ;;We're in a field loop
                 str = template.Context.GetCurrentStructure()
-                field = ((@FieldLoopNode)loop).CurrentField
+                field = ((@FieldLoopNode)loop).GetCurrentField()
                 index = ((@FieldLoopNode)loop).CurrentIndex
             end
             else if (loop .is. RelationSegmentLoopNode) then

CodeGenEngine/ExpressionEvaluators/ExpressionEvaluatorStructure.dbl

@@ -82,7 +82,7 @@ namespace CodeGen.Engine
             endparams
         proc
             ;;This is to trap the possible use of structure expressions in parameter loops, but with non-structure parameters
-            if (template.Context.CurrentStructure == ^null)
+            if (template.Context.GetCurrentStructure() == ^null)
             begin
                 throw new ApplicationException(String.Format("Attempt to use structure expression <IF {0}> with no current structure!",tkn.Value))
             end

CodeGenEngine/LoopExpander.dbl

@@ -55,8 +55,12 @@ namespace CodeGen.Engine
 
         private static loopProcessors, @Dictionary<string, Action<LoopNode, FileNode, IEnumerable<LoopNode>, ITreeNodeVisitor>>
 
+        ;;; <summary>
+        ;;; Constructor
+        ;;; </summary>
         static method LoopExpander
         proc
+            ;; Declare the methods responsible for processing each type of loop
 
             loopProcessors = new Dictionary<string, Action<LoopNode, FileNode, IEnumerable<LoopNode>, ITreeNodeVisitor>>()
 
@@ -107,10 +111,17 @@ namespace CodeGen.Engine
             required in loopContext,    @IEnumerable<LoopNode> 
             required in visitor,        @ITreeNodeVisitor 
         proc
+            ;; Lookup the processing method for the loop needing to be processed
             if (loopProcessors.ContainsKey(node.OpenToken.Value)) then
+            begin
+                ;; And call it
                 loopProcessors[node.OpenToken.Value](node, tpl, loopContext, visitor)
+            end
             else
-                throw new ApplicationException(String.Format("CODEGEN BUG: LoopExpander doesn't define a processor for <{0}>!", node.OpenToken.Value))
+            begin
+                ;; Not found (CodeGen bug)
+                throw new ApplicationException(String.Format("CODEGEN BUG: LoopExpander doesn't define a loop processor method for <{0}>!", node.OpenToken.Value))
+            end
         endmethod
 
         private static method processFieldLoop, void
@@ -139,7 +150,7 @@ namespace CodeGen.Engine
             data ix, int
             for ix from 0 thru currentStructure.Fields.Count - 1
             begin
-                loop.CurrentField = currentStructure.Fields[ix]
+                loop.SetCurrentField(currentStructure.Fields[ix])
                 loop.CurrentIndex = ix
                 expander.Visit(node.Body)
             end
@@ -1006,17 +1017,17 @@ namespace CodeGen.Engine
             data loop = ^as(node, SelectionLoopNode)
             data context = template.Context
 
-            if (outerLoop.CurrentField.SelectionList.Count > 0)
+            if (outerLoop.GetCurrentField().SelectionList.Count > 0)
             begin
-                loop.MaxIndex = outerLoop.CurrentField.SelectionList.Count - 1
-                loop.CurrentField = outerLoop.CurrentField
+                loop.MaxIndex = outerLoop.GetCurrentField().SelectionList.Count - 1
+                loop.CurrentField = outerLoop.GetCurrentField()
 
                 context.CurrentTask.DebugLog(String.Format("   - {0,-30} -> {1} selections", string.Format("<{0}>", loop.OpenToken.Value), loop.MaxIndex + 1))
 
                 data ix, int
-                for ix from 0 thru outerLoop.CurrentField.SelectionList.Count - 1
+                for ix from 0 thru outerLoop.GetCurrentField().SelectionList.Count - 1
                 begin
-                    loop.CurrentSelection = outerLoop.CurrentField.SelectionList[ix]
+                    loop.CurrentSelection = outerLoop.GetCurrentField().SelectionList[ix]
                     loop.CurrentIndex = ix
 
                     expander.Visit(node.Body)

CodeGenEngine/TokenExpanders/TokenExpanderFieldLoop.dbl

@@ -213,7 +213,7 @@ namespace CodeGen.Engine
             begin
                 ;;We're in a field loop
                 str = currentStructure
-                fld = ((@FieldLoopNode)loop).CurrentField
+                fld = ((@FieldLoopNode)loop).GetCurrentField()
             end
             else if (loop .is. RelationSegmentLoopNode) then
             begin

CodeGenEngine/TokenExpanders/TokenExpanderStructure.dbl

@@ -115,7 +115,7 @@ namespace CodeGen.Engine
             endparams
         proc
             ;;This is to trap the possible use of structure tokens in parameter loops, but with non-structure parameters
-            if (template.Context.CurrentStructure == ^null)
+            if (template.Context.GetCurrentStructure() == ^null)
             begin
                 throw new ApplicationException(String.Format("Attempt to use structure token <{0}> with no current structure!",tkn.Value))
             end

CodeGenEngine/TreeExpander.dbl

@@ -570,7 +570,7 @@ namespace CodeGen.Engine
             else
             begin
                 ;; No, we'll be going with a default output file name
-                if (node.Context.CurrentStructure == ^null) then
+                if (node.Context.GetCurrentStructure() == ^null) then
                     node.OutputFileName = String.Format("{0}.dbl", node.Context.CurrentTemplateBaseName.ToLower())
                 else
                     node.OutputFileName = String.Format("{0}_{1}.dbl", node.Context.GetCurrentStructure().Name.ToLower(), node.Context.CurrentTemplateBaseName.ToLower())

CodeGenEngine/TreeNodes.dbl

@@ -105,7 +105,45 @@ namespace CodeGen.Engine
     ;;; Represents a field loop token in a template file.
     ;;; </summary>
     public class FieldLoopNode extends LoopNode
-        public CurrentField, @RpsField
+        
+        private mCurrentField, @Stack<RpsField>, new Stack<RpsField>()
+
+        public method SetCurrentField, void
+            required in aField, @RpsField
+        proc
+            using mCurrentField.Count select
+            (0),
+                mCurrentField.Push(aField)
+            (),
+            begin
+                mCurrentField.Pop()
+                mCurrentField.Push(aField)
+            end
+            endusing
+        endmethod
+
+        public method GetCurrentField, @RpsField
+        proc
+            mreturn mCurrentField.Count > 0 ? mCurrentField.Peek() : ^null
+        endmethod
+
+        public method AddNestedField, void
+            required in aField, @RpsField
+        proc
+            if (mCurrentField.Count > 0) then
+                mCurrentField.Push(aField)
+            else
+                throw new ApplicationException("Can't add nested field when no main field is being processed!")
+        endmethod
+
+        public method RemoveNestedField, void
+        proc
+            if (mCurrentField.Count > 1) then
+                mCurrentField.Pop()
+            else
+                throw new ApplicationException("No nested field to remove!")
+        endmethod
+
     endclass
 
     ;;; <summary>