mORMot Open Source

nostroyo

Member

Registered: 2015-08-19

Posts: 16

Replacing Datasnap

Hi!

I try to replace Datasnap (i'm afraid of what i read about it's performance and stability) with mormot. I use Datasnap only for the http communication (the SOA part). Do you have any advices for my migration?

I have just finished reading this post, where can i find the full source?

Thanks!

ab

Administrator

From: France

Registered: 2010-06-21

Posts: 14,659

Website

Re: Replacing Datasnap

See https://github.com/synopse/mORMot/tree/ … %20Service

But interface-based services are much easier to work with.
See https://github.com/synopse/mORMot/tree/ … 20services

nostroyo

Member

Registered: 2015-08-19

Posts: 16

Re: Replacing Datasnap

OK i rewrote my client and server to use interface-based services, it's very powerful.

I have a problem when i want to use on the server side my object wich implement the interface, it's TServiceCalculator in the demo. never be Created, when a method is calling by the client an AV occur because the constructor never be called. I tried different Instances life time (sicSingle, sicShared...) but it doesn't change anything. Is there something i must do to solve this?

ab

Administrator

From: France

Registered: 2010-06-21

Posts: 14,659

Website

Re: Replacing Datasnap

I do not understand what you mean.

Instances are created on need, or may  be supplied for sicShared.

nostroyo

Member

Registered: 2015-08-19

Posts: 16

Re: Replacing Datasnap

Here my class on the server side :

  
TCollDbFunc = class(TInterfacedObject, IColleaguesFunc)
  private
    FDORMConfigCtrl: TDORMCtrl;
    FLstCtrl: TListCtrl;

    function GetAdvantagesList(ASession: TSession): TAdvantages;
  public
    constructor Create;
    destructor Destroy; override;


    function GetColleagues: string;
end;

When I call GetColleagues from the client, the constructor has never be called before so my nested object FDORMConfigCtrl is nil.

ab

Administrator

From: France

Registered: 2010-06-21

Posts: 14,659

Website

Re: Replacing Datasnap

The framework has no knowledge of this static constructor.

Just inherit from TInterfacedObjectWithCustomCreate, and override the default virtual constructor.
As stated by the doc in http://synopse.info/files/html/Synopse% … #TITLE_407

nostroyo

Member

Registered: 2015-08-19

Posts: 16

Re: Replacing Datasnap

Thank you it's working!