Added a new relation loop expression token <IF TO_DISPLAY_FIELD>, and a new relation loop expansion token <RELATION_TOSTRUCTURE_DISPLAY_FIELD>.

Author: SteveIves

CodeGenEngine/ExpressionEvaluators/ExpressionEvaluatorRelationLoop.dbl

@@ -92,6 +92,7 @@ namespace CodeGen.Engine
             relationLoopExpressionEvaluators.Add("TO_AUTO_TIMESTAMP", evaluateRelationToAutoTimestamp)
             relationLoopExpressionEvaluators.Add("TO_AUTO_TIMESTAMP_CREATED", evaluateRelationToAutoTimestampCreated)
             relationLoopExpressionEvaluators.Add("TO_AUTO_TIMESTAMP_UPDATED", evaluateRelationToAutoTimestampUpdated)
+            relationLoopExpressionEvaluators.Add("TO_DISPLAY_FIELD",evaluateRelationToDisplayField)
             relationLoopExpressionEvaluators.Add("TO_CHANGES", evaluateRelationToChanges)
             relationLoopExpressionEvaluators.Add("TO_DESCENDING", evaluateRelationToDescending)
             relationLoopExpressionEvaluators.Add("TO_DUPLICATES", evaluateRelationToDups)
@@ -400,6 +401,16 @@ namespace CodeGen.Engine
             mreturn EvaluateRelationLoopExpression(tkn, template, loops, doEvaluate)
         endmethod
 
+        private static method evaluateRelationToDisplayField, boolean
+            tkn, @Token 
+            template, @FileNode 
+            loops, @IEnumerable<LoopNode> 
+            endparams
+        proc
+            lambda doEvaluate(context, fromStructure, relation, index, fromkey, tostr, tokey) !String.IsNullOrWhiteSpace(tostr.DisplayField)
+            mreturn EvaluateRelationLoopExpression(tkn, template, loops, doEvaluate)
+        endmethod
+
         private static method evaluateRelationToChanges, boolean
             tkn, @Token 
             template, @FileNode 

CodeGenEngine/TokenExpanders/TokenExpanderRelationLoop.dbl

@@ -66,6 +66,7 @@ namespace CodeGen.Engine
             relationLoopTokenExpanders.Add("RELATION_NUMBER", expandRelationNumber)
             relationLoopTokenExpanders.Add("RELATION_TOKEY", expandRelationToKey)
             relationLoopTokenExpanders.Add("RELATION_TOSTRUCTURE", expandRelationToStructure)
+            relationLoopTokenExpanders.Add("RELATION_TOSTRUCTURE_DISPLAY_FIELD",expandRelationToStructureDisplayField)
             relationLoopTokenExpanders.Add("RELATION_TOSTRUCTURE_PLURAL", expandRelationToStructurePlural)
             relationLoopTokenExpanders.Add("RELATION_TOSTRUCTURE_NOPLURAL", expandRelationToStructureNoPlural)
 
@@ -164,6 +165,19 @@ namespace CodeGen.Engine
             mreturn ExpandRelationLoopToken(tkn, template, loops, doExpand)
         endmethod
 
+        private static method expandRelationToStructureDisplayField, string
+            tkn, @Token 
+            template, @FileNode 
+            loops, @IEnumerable<LoopNode> 
+            endparams
+        proc
+            lambda doExpand(str, relation, index, fromkey, tostr, tokey)
+            begin
+                mreturn tostr.DisplayField
+            end
+            mreturn ExpandRelationLoopToken(tkn, template, loops, doExpand)
+        endmethod
+
         private static method expandRelationToStructurePlural, string
             tkn, @Token 
             template, @FileNode 

CodeGenEngine/Tokenizer.dbl

@@ -439,6 +439,7 @@ namespace CodeGen.Engine
             &    { makeTokenMeta_AllVariants("RELATION_FROMKEY", TokenType.RelationLoop, TokenValidity.RelationLoop, true) }, 
             &    { makeTokenMeta_AllVariants("RELATION_TOKEY", TokenType.RelationLoop, TokenValidity.RelationLoop, true) }, 
             &    { makeTokenMeta_AllVariants("RELATION_TOSTRUCTURE", TokenType.RelationLoop, TokenValidity.RelationLoop, true) }, 
+            &    { makeTokenMeta_AllVariants("RELATION_TOSTRUCTURE_DISPLAY_FIELD", TokenType.RelationLoop, TokenValidity.RelationLoop, true) }, 
             &    { makeTokenMeta_AllVariants("RELATION_TOSTRUCTURE_PLURAL", TokenType.RelationLoop, TokenValidity.RelationLoop, true) }, 
             &    { makeTokenMeta_AllVariants("RELATION_TOSTRUCTURE_NOPLURAL", TokenType.RelationLoop, TokenValidity.RelationLoop, true) }, 
             &    { new TokenMeta() {Name = "FROM_KEY_CHANGES", TypeOfToken = TokenType.RelationLoop, IsPaired = false, Validity = TokenValidity.RelationLoop, RequiresRepository = true} }, 
@@ -1038,6 +1039,7 @@ namespace CodeGen.Engine
             expressions.Add("TO_AUTO_TIMESTAMP",                TokenValidity.RelationLoop)
             expressions.Add("TO_AUTO_TIMESTAMP_CREATED",        TokenValidity.RelationLoop)
             expressions.Add("TO_AUTO_TIMESTAMP_UPDATED",        TokenValidity.RelationLoop)
+            expressions.Add("TO_DISPLAY_FIELD",                 TokenValidity.RelationLoop)
             expressions.Add("TO_CHANGES",                       TokenValidity.RelationLoop)
             expressions.Add("TO_DESCENDING",                    TokenValidity.RelationLoop)
             expressions.Add("TO_DUPLICATES",                    TokenValidity.RelationLoop)