* Locate by default starts from 0th record. Add option to allow search from current. Fix date handling

packages/fcl-db/db.pas

@@ -1002,7 +1002,7 @@ type
   TUpdateAction = (uaFail, uaAbort, uaSkip, uaRetry, uaApplied);
   TUpdateKind = (ukModify, ukInsert, ukDelete);
 
-  TLocateOption = (loCaseInsensitive, loPartialKey);
+  TLocateOption = (loCaseInsensitive, loPartialKey, loFromCurrent);
   TLocateOptions = set of TLocateOption;
   TDataOperation = procedure of object;
 
@@ -1293,10 +1293,10 @@ type
     procedure Append;
     procedure AppendRecord(const Values: array of jsValue);
     function BookmarkValid(ABookmark{%H-}: TBookmark): Boolean; virtual;
-    function ConvertToDateTime(aValue : JSValue; ARaiseException : Boolean) : TDateTime; virtual;
-    function ConvertDateTimeToNative(aValue : TDateTime) : JSValue; virtual;
-    Class function DefaultConvertToDateTime(aValue : JSValue; ARaiseException{%H-} : Boolean) : TDateTime; virtual;
-    Class function DefaultConvertDateTimeToNative(aValue : TDateTime) : JSValue; virtual;
+    function ConvertToDateTime(aField : TField; aValue : JSValue; ARaiseException : Boolean) : TDateTime; virtual;
+    function ConvertDateTimeToNative(aField : TField; aValue : TDateTime) : JSValue; virtual;
+    Class function DefaultConvertToDateTime(aField : TField; aValue : JSValue; ARaiseException{%H-} : Boolean) : TDateTime; virtual;
+    Class function DefaultConvertDateTimeToNative(aField : TField; aValue : TDateTime) : JSValue; virtual;
     Function BlobDataToBytes(aValue : JSValue) : TBytes; virtual;
     Class Function DefaultBlobDataToBytes(aValue : JSValue) : TBytes; virtual;
     Function BytesToBlobData(aValue : TBytes) : JSValue ; virtual;
@@ -3867,12 +3867,12 @@ end;
 
 
 
-function TDataSet.ConvertToDateTime(aValue: JSValue; ARaiseException: Boolean): TDateTime;
+function TDataSet.ConvertToDateTime(aField: TField; aValue: JSValue; ARaiseException: Boolean): TDateTime;
 begin
-  Result:=DefaultConvertToDateTime(aValue,ARaiseException);
+  Result:=DefaultConvertToDateTime(aField,aValue,ARaiseException);
 end;
 
-class function TDataSet.DefaultConvertToDateTime(aValue: JSValue; ARaiseException: Boolean): TDateTime;
+class function TDataSet.DefaultConvertToDateTime(aField: TField; aValue: JSValue; ARaiseException: Boolean): TDateTime;
 begin
   Result:=0;
   if IsString(aValue) then
@@ -3884,13 +3884,13 @@ begin
     Result:=TDateTime(AValue)
 end;
 
-function TDataSet.ConvertDateTimeToNative(aValue : TDateTime) : JSValue;
+function TDataSet.ConvertDateTimeToNative(aField: TField; aValue : TDateTime) : JSValue;
 
 begin
-  Result:=DefaultConvertDateTimeToNative(aValue);
+  Result:=DefaultConvertDateTimeToNative(aField, aValue);
 end;
 
-Class function TDataSet.DefaultConvertDateTimeToNative(aValue : TDateTime) : JSValue;
+Class function TDataSet.DefaultConvertDateTimeToNative(aField : TField;aValue : TDateTime) : JSValue;
 
 begin
   Result:=DateTimeToRFC3339(aValue);
@@ -6735,18 +6735,20 @@ end;
 
 function TDateTimeField.ConvertToDateTime(aValue: JSValue; aRaiseError: Boolean): TDateTime;
 begin
-  if Assigned(Dataset) then
-    Result:=Dataset.ConvertToDateTime(aValue,aRaiseError)
+  if JS.isNull(aValue) then
+    Result:=0
+  else if Assigned(Dataset) then
+    Result:=Dataset.ConvertToDateTime(Self,aValue,aRaiseError)
   else
-    Result:=TDataset.DefaultConvertToDateTime(aValue,aRaiseError);
+    Result:=TDataset.DefaultConvertToDateTime(Self,aValue,aRaiseError);
 end;
 
 function TDateTimeField.DateTimeToNativeDateTime(aValue: TDateTime): JSValue;
 begin
   if Assigned(Dataset) then
-    Result:=Dataset.ConvertDateTimeToNative(aValue)
+    Result:=Dataset.ConvertDateTimeToNative(Self,aValue)
   else
-    Result:=TDataset.DefaultConvertDateTimeToNative(aValue);
+    Result:=TDataset.DefaultConvertDateTimeToNative(Self,aValue);
 end;
 
 function TDateTimeField.GetAsDateTime: TDateTime;
@@ -7107,9 +7109,9 @@ Var
 begin
   V:=GetData;
   if Assigned(Dataset) then
-    Result:=Dataset.ConvertToDateTime(V,True)
+    Result:=Dataset.ConvertToDateTime(Self,V,True)
   else
-    Result:=TDataset.DefaultConvertToDateTime(V,True)
+    Result:=TDataset.DefaultConvertToDateTime(Self,V,True)
 end;
 
 function TVariantField.GetAsFloat: Double;

packages/fcl-db/jsondataset.pas

@@ -282,6 +282,7 @@ type
     procedure SetRows(AValue: TJSArray);
     procedure SetRowType(AValue: TJSONRowType);
   protected
+    function ConvertDateTimeToNative(aField : TField; aValue : TDateTime) : JSValue; override;
     // Determine filter value type based on field type
     function FieldTypeToExpressionType(aDataType: TFieldType): TResultType; virtual;
     // Callback for IsNull filter function.
@@ -643,7 +644,7 @@ var
 
 begin
   D1:=Dataset.ConvertDateTimeField(String(GetFieldValue(Rowindex)),Self.Field);
-  D2:=TDateTime(aValue);
+  D2:=Dataset.ConvertDateTimeField(String(aValue),Self.Field);
   Result:=Round(D1-D2);
 end;
 
@@ -1085,6 +1086,15 @@ begin
   FRowType:=AValue;
 end;
 
+function TBaseJSONDataSet.ConvertDateTimeToNative(aField : TField; aValue: TDateTime): JSValue;
+begin
+  if jsISNan(aValue) then
+    Result:=Null
+  else
+    Result:=FormatDateTimeField(aValue,aField)
+
+end;
+
 
 function TBaseJSONDataSet.AllocRecordBuffer: TDataRecord;
 begin
@@ -1174,7 +1184,7 @@ begin
   Result:=TFPExpressionParser;
 end;
 
-function TBaseJSONDataSet.GetFilterIsNull(Const Args : TExprParameterArray) : TFPExpressionResult;
+function TBaseJSONDataSet.GetFilterIsNull(const Args: TExprParameterArray): TFPExpressionResult;
 
 begin
   Result.ResultType:=rtBoolean;
@@ -1201,7 +1211,7 @@ begin
   end;
 end;
 
-function TBaseJSONDataSet.GetFilterField(Const AName : String) : TFPExpressionResult;
+function TBaseJSONDataSet.GetFilterField(const AName: String): TFPExpressionResult;
 
 Var
   F : TField;
@@ -1265,7 +1275,7 @@ begin
   end;
 end;
 
-function TBaseJSONDataSet.GetRecord(Var Buffer: TDataRecord; GetMode: TGetMode; DoCheck: Boolean): TGetResult;
+function TBaseJSONDataSet.GetRecord(var Buffer: TDataRecord; GetMode: TGetMode; DoCheck: Boolean): TGetResult;
 
 Var
   BkmIdx : Integer;
@@ -1689,7 +1699,7 @@ begin
   inherited;
 end;
 
-Function TBaseJSONDataSet.CreateIndexDefs : TJSONIndexDefs;
+function TBaseJSONDataSet.CreateIndexDefs: TJSONIndexDefs;
 
 begin
   Result:=TJSONIndexDefs.Create(Self,Self,TJSONIndexDef);
@@ -1722,7 +1732,10 @@ begin
   Result:=-1;
   Comp:=RecordComparerClass.Create(Self,KeyFields,KeyValues,Options);
   try
-    I:=FCurrent;
+    if loFromCurrent in Options then
+      I:=FCurrent
+    else
+      I:=0;
     RI:=FCurrentIndex.GetRecordIndex(I);
     While (Result=-1) and (RI<>-1) do
       begin