Update TActiveTextValidator and private TErrorInfo

Validator was updated to check that any non-empty active text is topped
and tailed by ekDocument elements.

Rewrite TActiveTextValidator.ValidateDocumentStructure to call into
IActiveText.IsValidActiveTextDocument to do the heavy lifting.

Removed unused Element field from TErrorInfo private advanced record of
TActiveTextValidator. Modified constructor and calls to it accordingly.

Author: delphidabbler

Src/ActiveText.UValidator.pas

@@ -36,16 +36,11 @@       TErrorInfo = record
       public
         ///  <summary>Error code.</summary>
         Code: TErrorCode;
-        ///  <summary>Reference to element causing problem.</summary>
-        ///  <remarks>May be nil if error doesn't relate to an element.
-        ///  </remarks>
-        Element: IActiveTextElem;
         ///  <summary>Description of error.</summary>
         Description: string;
         ///  <summary>Constructs a record. Sets fields from parameter values.
         ///  </summary>
-        constructor Create(const ACode: TErrorCode; AElement: IActiveTextElem;
-          const ADescription: string); overload;
+        constructor Create(const ACode: TErrorCode; const ADescription: string);
       end;
   strict private
     ///  <summary>Validates given link element.</summary>
@@ -56,6 +51,14 @@       TErrorInfo = record
     ///  <returns>Boolean. True on success or False on failure.</returns>
     class function ValidateLink(LinkElem: IActiveTextActionElem;
       out ErrInfo: TErrorInfo): Boolean; static;
+    ///  <summary>Validates document structure.</summary>
+    ///  <param name="ActiveText">IActiveText [in] Active text to be validated.
+    ///  </param>
+    ///  <param name="ErrInfo">TErrorInfo [out] Contains error information if
+    ///  validation fails. Undefined if validation succeeds.</param>
+    ///  <returns>Boolean. True on success or False on failure.</returns>
+    class function ValidateDocumentStructure(ActiveText: IActiveText;
+      out ErrInfo: TErrorInfo): Boolean; static;
   public
     ///  <summary>Validates given active text.</summary>
     ///  <param name="ActiveText">IActiveText [in] Active text to be validated.
@@ -92,6 +95,9 @@ class function TActiveTextValidator.Validate(ActiveText: IActiveText;
 begin
   if ActiveText.IsEmpty then
     Exit(True);
+  // Validate document structure
+  if not ValidateDocumentStructure(ActiveText, ErrInfo) then
+    Exit(False);
   // Validate elements
   for Elem in ActiveText do
   begin
@@ -115,6 +121,16 @@ class function TActiveTextValidator.Validate(ActiveText: IActiveText): Boolean;
   Result := Validate(ActiveText, Dummy);
 end;
 
+class function TActiveTextValidator.ValidateDocumentStructure(
+  ActiveText: IActiveText; out ErrInfo: TErrorInfo): Boolean;
+resourcestring
+  sNoDocTags = 'Document must start and end with document tags';
+begin
+  Result := ActiveText.IsValidActiveTextDocument;
+  if not Result then
+    ErrInfo := TErrorInfo.Create(errBadStructure, sNoDocTags);
+end;
+
 class function TActiveTextValidator.ValidateLink(
   LinkElem: IActiveTextActionElem; out ErrInfo: TErrorInfo): Boolean;
 resourcestring
@@ -150,7 +166,7 @@   TProtocolInfo = record
         < Length(PI.Protocol) + PI.MinURLLength then
       begin
         ErrInfo := TErrorInfo.Create(
-          errBadLinkURL, LinkElem, Format(sURLLengthErr, [URL])
+          errBadLinkURL, Format(sURLLengthErr, [URL])
         );
         Exit(False);
       end;
@@ -160,17 +176,16 @@   TProtocolInfo = record
   // No supported protocol
   Result := False;
   ErrInfo := TErrorInfo.Create(
-    errBadLinkProtocol, LinkElem, Format(sURLProtocolErr, [URL])
+    errBadLinkProtocol, Format(sURLProtocolErr, [URL])
   );
 end;
 
 { TActiveTextValidator.TErrorInfo }
 
 constructor TActiveTextValidator.TErrorInfo.Create(const ACode: TErrorCode;
-  AElement: IActiveTextElem; const ADescription: string);
+  const ADescription: string);
 begin
   Code := ACode;
-  Element := AElement;
   Description := ADescription;
 end;