delphimvcframework global variable

[borni69 1]

Hi ,

I have downloaded the delphimvcframework and it look’s great 🙂 thanks to  @Daniele Teti , I have also bought the book 🙂 great reading, recommended. 

I love this system , but will play more with it next couple of weeks.

 

A small question.

 

We have a small webbroker app  today running on Apache AWS, we use a globale Dict as a keystore in all requests, and we use FMX data pooling.

FMX data pooling seems to be well documented in your book, and I guess I can almost use like before.  

 

If you look at below code we use dict String_Dict as a global variable handled by

TMultiReadExclusiveWriteSynchronizer, any suggestion where to put his variable in delphimvcframework to be able to use it in the different controller / actions

like FMVC.AddController(TCustomersController);

 

In our webmodule we have a global variable and we use it with TMultiReadExclusiveWriteSynchronizer from system.sysutil

 

Example data from from our Webmodule

 

…
public
    { Public declarations }
    SettingTemplateClass : TSettingTemplateClass;
end:


var
  WebModuleClass: TComponentClass = TWebModule1;

  String_Dict      : TDictionary<string,String > ;
  string_Dict_Sync : TMultiReadExclusiveWriteSynchronizer;


…..
// connecting String_Dict to a setting class unique for each request

procedure TWebModule1.WebModuleCreate(Sender: TObject);
begin
  SettingTemplateClass := TSettingTemplateClass.Create
  SettingTemplateClass.string_Dict_Sync   := string_Dict_Sync;
  SettingTemplateClass.String_Dict        := String_Dict;
….
end;

// a typical request  sending  string_dict further  using settingTemplateClass to the class generating the response via usersession class
procedure TWebModule1.WebModule1getlogondataAction(Sender: TObject;
  Request: TWebRequest; Response: TWebResponse; var Handled: Boolean);
var
 userSession      : TuserSession;
 ssoInternalClass  : TssoInternalClass;
 companyid        : Integer;
 lsession_data    : String;

begin

 companyid      := strtointdef( getRequestParamValue (Request , 'companyid' ),0);
 userSession := TuserSession.create(SettingTemplateClass,getRequestParamValue(request,'token'));

  try
    if isSessionValid(Response,userSession) then
    begin
       lsession_data :=getRequestParamValue (Request , 'session_data' );
       userSession.userSessionData.setSessionData(lsession_data);

       ssoInternalClass  := TssoInternalClass.Create(userSession);
       try
          Response.content  :=  ssoInternalClass.getLogonData( companyid  );
       finally
         ssoInternalClass.Free;
       end;
    end;
  finally
   userSession.Free;
  end;

end;

…………

initialization

  String_Dict      := TDictionary<string,String >.create ;
  string_Dict_Sync := TMultiReadExclusiveWriteSynchronizer.Create;


finalization

  String_Dict.Free;
  string_Dict_Sync.Free;

Example using string_dict in class generating the response data below .

 

 

 string_Dict_Sync.BeginRead;
    try
      string_Dict.TryGetValue('severDayNumberString',  severDayNumberString );
    finally
     string_Dict_Sync.EndRead;
    end;

 

 

It it possible o do something similar with delphimvcframework,   ?

For me it seems like difficult to share data to a controller .. 

Thanks in advance

Edited January 25, 2022 by borni69

[Alberto Fornés 22]

Yes, you can use this in delphimvcframework. I declare such dictionary in the service unit (it's a windows service), or you can put it in a datamodule and create it at program start and destroy at the end. Webmodule can be created and destroyed several times during program execution.

[borni69 1]

3 hours ago, Alberto Fornés said:

Yes, you can use this in delphimvcframework. I declare such dictionary in the service unit (it's a windows service), or you can put it in a datamodule and create it at program start and destroy at the end. Webmodule can be created and destroyed several times during program execution.

Thanks, I can create it in a datamodule, but I still do not understand howto get this datamodule all the way down to the controller..

 

FMVC.AddController(TCustomersController);

 

Tcustomercontroller is a class created on request  ,and the dict is created at startup.

 

I undestand that I can use/create a datamodule in the controller, but not howto use one created at startup, holding all the data,, normally I would send the dict to my class using a variable.

procedure TMyController.GetCustomers ;
  var 
   lCustomersModule : TMyDataModule ; 
    begin 
     lCustomersModule := TMyDataModule . Create ( nil ) ; 
      try 
       lCustomersModule . QryCustomers . Open () ; 

 

again thanks

 

  I will also try a few options myself...

Edited January 26, 2022 by borni69

[Alberto Fornés 22]

36 minutes ago, borni69 said:

Thanks, I can create it in a datamodule, but I still do not understand howto get this datamodule all the way down to the controller..

 

FMVC.AddController(TCustomersController);

 

Tcustomercontroller is a class created on request  ,and the dict is created at startup.

 

I undestand that I can use/create a datamodule in the controller, but not howto use one created at startup, holding all the data,, normally I would send the dict to my class using a variable.

procedure TMyController.GetCustomers ;
  var 
   lCustomersModule : TMyDataModule ; 
    begin 
     lCustomersModule := TMyDataModule . Create ( nil ) ; 
      try 
       lCustomersModule . QryCustomers . Open () ; 

 

again thanks

 

  I will also try a few options myself...

No , this datamodule should be created at start, and always alive, you reference it from your controller (add datamodule unit to controller), and access it through TMultiReadExclusiveWriteSynchronizer.

[borni69 1]

12 minutes ago, Alberto Fornés said:

No , this datamodule should be created at start, and always alive, you reference it from your controller (add datamodule unit to controller), and access it through TMultiReadExclusiveWriteSynchronizer.

OKI  thanks alot 🙂

[borni69 1]

21 hours ago, borni69 said:

OKI  thanks alot 🙂

This is my result from test..  and it seems to work..

 

unit HseqDmDictU;

interface

uses
  System.SysUtils, System.Classes,  Generics.collections;

type
  TDataModuleDict = class(TDataModule)
  private
    FString_Dict: TDictionary<string, String>;
    Fstring_Dict_Sync: TMultiReadExclusiveWriteSynchronizer;
    procedure SetString_Dict(const Value: TDictionary<string, String>);
    procedure Setstring_Dict_Sync(
      const Value: TMultiReadExclusiveWriteSynchronizer);
    { Private declarations }
  public
    { Public declarations }

    destructor Destroy; override;
    procedure initDict;

    property  String_Dict      : TDictionary<string,String >  read FString_Dict write SetString_Dict;
    property  string_Dict_Sync : TMultiReadExclusiveWriteSynchronizer read Fstring_Dict_Sync write Setstring_Dict_Sync;


  end;

var
  DataModuleDict: TDataModuleDict;


implementation

{%CLASSGROUP 'System.Classes.TPersistent'}

{$R *.dfm}


{ TDataModuleDict }

procedure TDataModuleDict.initDict;
begin
    FString_Dict      := TDictionary<string,String >.create ;
    Fstring_Dict_Sync := TMultiReadExclusiveWriteSynchronizer.Create;
end;

destructor TDataModuleDict.Destroy;
begin
    FString_Dict.Free;
    Fstring_Dict_Sync.Free;

  inherited;
end;

procedure TDataModuleDict.SetString_Dict(
  const Value: TDictionary<string, String>);
begin
  FString_Dict := Value;
end;

procedure TDataModuleDict.Setstring_Dict_Sync(
  const Value: TMultiReadExclusiveWriteSynchronizer);
begin
  Fstring_Dict_Sync := Value;
end;

end.

 

On my console app startup init the Datamodule  (not sure for Linux where I will put it, but will try later)

 

begin
  ReportMemoryLeaksOnShutdown := True;
  IsMultiThread := True;
  // Prepare Dict
  DataModuleDict:= TDataModuleDict.Create(nil);
  try
     DataModuleDict.initDict;  // Important
      try
        if WebRequestHandler <> nil then
          WebRequestHandler.WebModuleClass := WebModuleClass;
        WebRequestHandlerProc.MaxConnections := 1024;
        RunServer(8080);
      except
        on E: Exception do
          Writeln(E.ClassName, ': ', E.Message);
      end;


  finally

    DataModuleDict.Free;

  end;


end.

 

Using dict in code from  seperate unit 

 

unit DictU;

interface
uses
   system.sysutils , system.classes ,DataConU,
   Generics.collections ,  TemplateRecordU;

 type
    TDictClassV2 = Class ( Tobject )
     private

     public
      procedure   saveString         ( akey   , avalue : String ) ;
      function    loadString         ( akey            : String ) :String;

    End;

implementation

uses HseqDmDictU;

{ TDictClassV2 }

function TDictClassV2.loadString(akey: String): String;
begin
 result:='';
  DataModuleDict.string_Dict_Sync.BeginRead;
 try
   DataModuleDict.string_Dict.TryGetValue(akey,result);
 finally
   DataModuleDict.string_Dict_Sync.EndRead;
 end;



end;

procedure TDictClassV2.saveString(akey, avalue: String);
begin
  DataModuleDict.string_Dict_Sync.BeginWrite;
     try
      try
        if not DataModuleDict.String_Dict.ContainsKey(akey) then
            DataModuleDict.String_Dict.Add(akey,avalue);
       Except
          on E : Exception do
         begin
              // logg error
         end;
      end;
     finally
       DataModuleDict.string_Dict_Sync.EndWrite;
     end;


end;

end.

 

If you would do it differently please let me know  Thanks again...