I'm using SuperObject library for working with JSON.
This code creates JSON:
procedure TfmMain.btnIngredientsSaveClick(Sender: TObject);
var obj: ISuperObject;
i: integer;
begin
try
obj := SO();
for i := 0 to sgIngredients.RowCount - 2 do
begin
obj.O[sgIngredients.Cells[0, i+1]] := SA([]);
obj.A[sgIngredients.Cells[0, i+1]].S[0] := sgIngredients.Cells[1, i+1];
obj.A[sgIngredients.Cells[0, i+1]].S[1] := sgIngredients.Cells[2, i+1];
end;
obj.SaveTo(ExtractFileDir(Application.ExeName)+ingrJSONFile);
finally
obj := nil;
end;
end;
sgIngredients - TStringGrid
sgIngredients contain cyrillic symbols. So output file is:
{
"4":["Hello","count"],
"3":["\u0411\u0443\u043b\u044c\u043e\u043d \u043e\u0432\u043e\u0449\u043d\u043e\u0439","\u0441\u0442."],
"2":["\u0411\u0443\u043b\u044c\u043e\u043d \u043a\u0443\u0440\u0438\u043d\u044b\u0439","\u0441\u0442."],
"1":["\u0411\u0435\u043a\u043e\u043d","\u0433\u0440."]
}
How to correctly save my data to JSON-file?
EDIT
This is screenshot of my string grid.
Reading the sources, you can call function TSuperObject.SaveTo(stream: TStream; indent, escape: boolean): integer; setting escape := false
I can say it again, when using libraries with their source code given, just "Use the Source, Luke"
Also, u may save JSON to string, and then replace escaped characters with actual WideChar values (like was done in http://UniRed.sf.net or at http://www.sql.ru/forum/936760/perevesti-kodirovannye-simvoly-funkciya-v-delphi-analog-iz-js) and then save the resulting string to file while enforcing UTF-8 charset.
Related
I use Rad studio 11. I read information from json file (file is UTF8 encoded) and convert to jsonobject.
Then I make changes to this jsonobject and want to save to json file. The information is successfully written to the file, but the file has the Windows-1251 encoding. What needs to be done to make the file encoding UTF8? It's need me because json file include russian symbols (in Windows-1251 encoding it's looking like '?').
I read from a file like this:
var inputfile:TextFile;
str:string;
...
if OpenDialog1.Execute then begin
AssignFile(inputfile, OpenDialog1.FileName);
reset(inputfile);
while not Eof(inputfile) do
begin
ReadLn(inputfile, str);
str1 := str1+UTF8ToANSI(str);
end;
closefile(inputfile);
end;
I convert to Jsonobject like this:
LJsonObj:=TJSONObject.ParseJSONValue(str1) as TJSONobject;
Trying to save JsonObject like this:
var
listStr: TStringList;
Size: Integer;
I: Integer;
...
Size := Form3.LJsonObj.Count;
liststr := TStringList.Create;
try
listStr.Add('{');
if Size > 0 then
listStr.Add(LJsonObj.Get(0).ToString);
showmessage(LJsonObj.Get(0).ToString);
for I := 1 to Size - 1 do
begin
listStr.Add(',');
listStr.Add(ANSITOUTF8(LJsonObj.Get(I).ToString));
end;
listStr.Add('}');
// Form1.filepath-is path of file,form1.filename-name of file without file extension
listStr.SaveToFile(Form1.filepath+'\'+form1.filename+'.json');
finally
listStr.Free;
end;
Why are you reading the file using old-style Pascal file I/O? And why are you converting between UTF-8 and ANSI? You are using a Unicode version of Delphi, you should not be dealing with ANSI at all.
In any case:
When reading the file, consider using TStringList.LoadFromFile() or TFile.ReadAllText() instead. Both allow you to specify UTF-8 as the source encoding.
When writing the file, consider using TStringList.SaveToFile() or TFile.WriteAllText() instead. Both allow you to specify UTF-8 as the target encoding.
For example:
var
inputfile: TStringList;
str1: string;
...
begin
...
inputfile := TStringList.Create;
try
inputfile.LoadFromFile(OpenDialog1.FileName, TEncoding.UTF8);
str1 := inputfile.Text;
finally
inputfile.Free;
end;
...
end;
...
var
listStr: TStringList;
...
begin
...
listStr.SaveToFile(Form1.filepath + '\' + form1.filename + '.json', TEncoding.UTF8);
...
end;
var
str1: string;
...
begin
...
str1 := TFile.ReadAllText(OpenDialog1.FileName, TEncoding.UTF8);
...
end;
...
var
listStr: TStringList;
...
begin
...
TFile.WriteAllText(listStr.Text, TEncoding.UTF8);
...
end;
Note that you don't really need to use a TStringList to build up JSON syntax manually. TJSONObject has ToString() and ToJSON() methods to handle that for you. But, if you really want to build up your own JSON syntax manually, consider using TJSONObjectBuilder or TJsonTextWriter for that purpose instead.
No need to loop over the JSONObject. Just use:
TFile.WriteAllBytes(Form1.filepath+'\'+form1.filename+'.json',TEncoding.UTF8.GetBytes(LJsonObj.ToJSON))
So I'm talking to this webserver, and it's returning me a json entry like this:
{
"result": [
[],
["{\"success\": \"true\", \"Message\":\"User 1 has been deleted.\"}"]
]
}
{"result":[[],["{\"success\": \"true\", \"Message\":\"User 1 has been deleted.\"}"]]}
And I'm having trouble getting things out of it.
Looking at it, I made a jsonobject, pulled the value of result and made it an array, then pulled the second entry of the first array as another array, then took that jsonstring and turned it into another jsonarray, then took the values out.
but for some reason the first jsonarray claims to have two values, both of which are empty. I'm sure there are other errors in my approach past that point as well.
Can I get a hand ironing this thing out?
procedure DeleteUser;
var
aJSON, aResult : String;
aJsonResponse : TJsonObject;
aResultArrayA : TJsonArray;
aResultArrayB : TJsonArray;
aResultArrayC : TJsonArray;
aParsed : TJsonValue;
i : Integer;
Begin
aresult := '{"result":[[],["{\"success\": \"true\", \"Message\":\"User 1 has been deleted.\"}"]]}';
aJsonResponse := TJsonObject.ParseJSONValue(aResult) as TJsonObject;
if not (aJsonResponse is TJsonObject) then
raise Exception.Create('InvalidResponse');
aResultArrayA := aJsonResponse.getValue('result') as TJsonArray;
if aResultArrayA.Count <= 0 then //is 2
raise Exception.Create('InvalidResponse');
aJSON := aResultArrayA.Items[0].Value; // is ''
aJSON := aResultArrayA.Items[1].Value; // is ''
aResultArrayB := aResultArrayA.Items[0] as TJSONArray;
if aResultArrayB.Count <= 0 then // is 0
raise Exception.Create('InvalidResponse'); //raises here
aJSON := aResultArrayB.Items[0].Value;
aJSON := aResultArrayB.Items[1].Value;
aResultArrayC := TJSONObject.ParseJSONValue(aResultArrayB.Items[1].Value) as TJSONArray;
for aParsed in aResultArrayC do begin
aJson := aJson + aParsed.GetValue<string>('success') + ' ';
aJson := aJson + aParsed.GetValue<string>('message') + ' ';
end;
end;
Thanks everyone.
I really think that the best way to work with JSON is serialization and deserialization. Yes, there is some situations when it's better to use parsing, but look at this:
uses ...,Rest.Json;
TMyArray = ARRAY of ARRAY of string;
//class for deserialization outer JSON object
TMyParse = CLASS
private
FResult:TMyArray;
procedure SetResult(const Value: TMyArray);
public
property result:TMyArray read FResult write SetResult;
END;
//class for deserialization inner JSON object
TMyInnerParse = class
private
FSuccess:Boolean;
FMessage:string;
procedure SetMessage(const Value: String);
procedure SetSuccess(const Value: Boolean);
public
property success:Boolean read FSuccess write SetSuccess;
property message:String read FMessage write SetMessage;
end;
procedure DeleteUser;
var
OuterObj: TMyParse;
InnerObj: TMyInnerParse;
aResult: String;
i,j: Integer;
Begin
aResult := '{"result":[[],["{\"success\": \"true\", \"Message\":\"User 1 has been deleted.\"}"]]}';
try
OuterObj := TJson.JsonToObject<TMyParse>(aResult);
if Length(OuterObj.result) > 0 then
for i := 0 to Length(OuterObj.result) - 1 do
if length(OuterObj.result[i]) > 0 then
for j := 0 to Length(OuterObj.result[i]) - 1 do
begin
try
InnerObj := TJson.JsonToObject<TMyInnerParse>(OuterObj.result[i][j]);
//Do your work with result, that in InnerObj now
finally
if assigned(InnerObj) then
FreeAndNil(InnerObj);
end;
end;
finally
if assigned(OuterObj) then
FreeAndNil(OuterObj);
end;
end;
procedure TMyParse.SetResult(const Value: TMyArray);
begin
FResult := value;
end;
procedure TMyInnerParse.SetMessage(const Value: String);
begin
FMessage := value;
end;
procedure TMyInnerParse.SetSuccess(const Value: Boolean);
begin
FSuccess := value;
end;
For cycles in this code are awful, but it's the fastest way to show how you can solve your problem. And it's working.
I don't know what information can be in first empty array and this can be the reason for exceptions. Look at this code as working example, not full solution because lack of information.
It was tested on Delphi 10.1:
P.S. Using arrays are very old way of coding in this situation. But some time ago I met problem with serializing/deserializing TList and TObjectList. I'll try to use them and will return with result.
P.P.S. It tried to use TList, but my attempt fails. Maybe someone can describe how to implement it in a code above.
Found these functions in system.JSON and they just clicked for me.
/// <summary>Finds a JSON value and returns reference to it. </summary>
/// <remarks> Raises an exception when a JSON value could not be found. </remarks>
property P[const APath: string]: TJSONValue read GetValueP;{ default;}
property A[const AIndex: Integer]: TJSONValue read GetValueA;
var
aSuccess, aMessage : String
aJSON : TJSONObject;
begin
var aJSON:= TJSONObject.ParseJSONValue('{"result":[[],["{\"success\": \"true\", \"Message\":\"User has been deleted.\"}"]]}');
aSuccess := TJSONObject.ParseJSONValue(aJSON.P['result'].A[1].A[0].AsType<String>).P['success'].AsType<String>;
aMessage := TJSONObject.ParseJSONValue(aJSON.P['result'].A[1].A[0].AsType<String>).P['Message'].AsType<String>;
end;
Note that this needs exception handling, all of these functions will throw an exception if they fail to find the specified property.
I want to experiment (in Delphi code) with the XSLT 3.0 and its json-to-xml() function:
In XSLT 3.0, an inbound document can be in JSON, rather than XML. The processor can take that document, use the json-to-xml() function to convert it into a specific known XML format, process that through the templates, then convert the resulting output back into JSON (or can convert it into HTML 5 among other formats
But I'm stuck in two places:
How do I use a JSON string as the source for the transform? Trying to loading it into a TXMLDocument gives me (of course?) 'malformed' errors
How would I then apply the "json-to-xml() function". All the examples I find about using XSLT transforms in Delphi use the TransformNode function, as the below code.
Things like lDoc.Node.json-to-xml do not compile.
.
var
lDoc, lXSL, lRes: IXMLDocument;
lUTF8Str : UTF8String;
begin
lDoc := LoadXMLData(AXMLString);
lXSL := LoadXMLData(cRemoveNSTransform);
lRes := NewXMLDocument;
lDoc.Node.TransformNode(lXSL.Node,lRes); // Param types IXMLNode, IXMLDocument
lRes.SaveToXML(lUTF8Str);
Can anyone point me in the right direction?
I'm going to write a 'guide' to my own question that does not use XSLT but instead uses the IP*Works! Delphi components that we have a subscription for.
This may at least give others an available option, or a rough idea how to 'roll your own'.
We use the IP*Works! TipwJSON and TipwXML components.
The trick is to intercept the parsing of the JSON component and then write the detected data to the XML component.
This is code from a test app showing how we did it (I have left logging code in):
TJSONTOXML = class(TIpwJSON)
private
FXML : TipwXML;
FLogLevel : Integer;
procedure ShowLogLine(AMsg: String);
procedure InterceptJSONStartElement(Sender: TObject; const Element: string);
procedure InterceptJSONEndElement(Sender: TObject; const Element: string);
procedure InterceptCharacters(Sender: TObject; const Text: string);
function GetXML: String;
public
property XML: String read GetXML;
constructor Create(AOwner: TForm; ALogLevel: Integer); overload; // For now testing on a Form
end;
constructor TJSONTOXML.Create(AOwner: TForm; ALogLevel: Integer);
begin
inherited Create(AOwner);
FLogLevel := ALogLevel;
Self.BuildDOM := false;
Self.OnStartElement := InterceptJSONStartElement;
Self.OnEndElement := InterceptJSONEndElement;
Self.OnCharacters := InterceptCharacters;
FXML := TipwXML.Create(nil);
end;
procedure TJSONTOXML.InterceptJSONEndElement(Sender: TObject; const Element: string);
begin
if Element = '' then // End of array
begin
if FLogLevel > 2 then ShowLogLine('JSON parse EndElement - Array');
FXML.EndElement;
end
else
begin
if FLogLevel > 2 then ShowLogLine('JSON parse EndElement - Element: ' + Element);
FXML.EndElement;
end;
end;
procedure TJSONTOXML.InterceptJSONStartElement(Sender: TObject; const Element: string);
begin
if Element = '' then // Start of array
begin
if FLogLevel > 2 then ShowLogLine('JSON parse StartElement - Array');
FXML.StartElement('ARRAY','');
end
else
begin
if FLogLevel > 2 then ShowLogLine('JSON parse StartElement - Element: ' + Element);
FXML.StartElement(Uppercase(Element),'');
end;
end;
procedure TJSONTOXML.ShowLogLine(AMsg: String);
// Use WM_COPYDATA to send log info to form
var CopyDataStruct: TCopyDataStruct;
begin
CopyDataStruct.dwData := 0;
CopyDataStruct.cbData := 2 + 2 * Length(AMsg);
CopyDataStruct.lpData := PChar(AMsg);
SendMessage((Owner as TForm).Handle, WM_COPYDATA, (Owner as TForm).Handle, lParam(#CopyDataStruct));
end;
function TJSONTOXML.GetXML: String;
begin
FXML.EndElement;
Result := FXML.OutputData;
end;
procedure TJSONTOXML.InterceptCharacters(Sender: TObject; const Text: string);
var lText: String;
begin
// Always surrounded by quotes, remove:
lText := StripQuotes(Text);
if FLogLevel > 2 then ShowLogLine('JSON parse characters: ' + lText);
FXML.PutString(lText);
end;
With this you can
lJSONToXML := TJSONTOXML.Create(Self,FDataLogLvl);
// Get your JSON data from somewhere, e.g. a HTTP component. Then:
lJSONToXML.Inputdata := lData;
lJSONToXML.Parse; // The Parse method initiates the parsing that was postponed by setting BuildDom := false
// The XML is now in the OutputData property of the TipwXML and can e.g. be retrieved by our:
lOutputData := lJSONToXML.XML;
Note that:
There is no namespace information in the XML
The JSON arrays when converted to XML are converted to nodes named ARRAY
All data is kept in memory
I wanna parse JSON than have UTF-8 string but when I show this value in delphi XE3 in a label just show ???? but when show in ShowMessage(); this value is correct please help me
value: 'سعید'
my code:
procedure TServerMethods1.Ins_Info(var TehResult: String);
var
name: string;
js,xs:TlkJSONobject;
begin
js := TlkJSON.ParseText(ThResult) as TlkJSONobject;
if not assigned(js) then
begin
readln;
exit;
end
else
begin
name := AnsiToUtf8(js.getString('name'));
end;
end;
According to the source of lkJSON unit, there is an unnecessary Decode from UTF8 :
{$ifdef USE_D2009}
js.FValue := UTF8ToString(ws);
{$else}
js.FValue := UTF8Decode(ws);
{$endif}
If your JSON Strings are not encoded in UTF8, find and comment this lines and just assign ws value to the js.FValue :
...
js := TlkJSONstring.Create;
//{$ifdef USE_D2009}
// js.FValue := UTF8ToString(ws);
//{$else}
// js.FValue := UTF8Decode(ws);
//{$endif}
js.FValue := ws;
...
and there is no need to use AnsiToUtf8 or such methods, just use getString :
name := js.getString('name');
I'm getting JSON data back from a PHP call using TIdHTTP. I'm expecting to use TJSONObject but can't work out how to use it for this purpose. And there are no examples in the XE3 help.
Sample JSON data
[{"fleet_id":"2","fleet":"EMB195"},{"fleet_id":"3","fleet":"EMB175"},{"fleet_id":"1","fleet":"DHC84-400Q"}]
I'm sure this is simple, but how!
Thanks.
Use TJsonObject.ParseJsonValue to convert the input string into a JSON value:
var
val: TJsonValue;
s := '[{"fleet_id":"2","fleet":"EMB195"},{"fleet_id":"3","fleet":"EMB175"},{"fleet_id":"1","fleet":"DHC84-400Q"}]';
val := TJsonObject.ParseJsonValue(s);
In this case, the JSON happens to represent an array, so you can type-cast it to that:
var
arr: TJsonArray;
arr := val as TJsonArray;
You can access the elements of the array with Get, and type-cast the results to TJsonObject.
var
i: Integer;
elem: TJsonObject;
for i := 0 to Pred(arr.Size) do begin
elem := arr.Get(i) as TJsonObject;
end;
To inspect the properties of the object, you can use the Get method, which returns a TJsonPair holding the name and value.