Thursday, 9 September 2021

My favorite %11 new things in Delphi 11 Alexandria

- or all things "eleven", watch out for dialects.

With the public release of Delphi 11 (and RADStudio and C++Builder) today, I would like to share my %11 initial favorites in the new release.

%01. Styled Form designer

Together with the IDE HighDPI support, it is great that the gap between the running UI and the UI while designing has been reduced, and keeps in my opinion Delphi IDEs the best to design visual applications - whether it is on desktop OSs or mobile OSs.

%10. HTTP/2 support

I am looking forward to start experimenting with this, and see how much benefit and performance it will give when taking advantage of fully.

%11. Remote Desktop Support improvement

In this world where more people are coming to their senses, and wish to work remotely, focus on improving the IDE experience with remote connection is nice. And the things done can also benefit the applications build.


But there are many other things that not even a list of $11 things would cover it, and I am really looking forward to also experience to the various optimizations and running the IDE in HighDPI on my old Surface Pro.

Go EMBT :)

There is one slightly annoying thing that might split the Delphi community - adding to the list of:

- Is Delphi pronounced /del·fai/ or /del·fee/?

- Does "then begin" go on together on the same line?

- FreeAndNil?

and now this to split the community further and create fractions:


https://youtu.be/BOUTfUmI8vs

Well the above was just an excuse for me to include that funny Scottish sketch - no harm done I hope.

BTW: If you wonder about the % prefix - the it is the prefix for binary literals adding in Delphi 11.

/Enjoy


Saturday, 22 May 2021

VAT's in it for me? - or I call my layer.

 - or a shout-out to the various services of apilayer.com



Sorry about the intended pun in the title - but it will all make sense.

Have you ever wanted to know the various VAT rates in the EU - no? - well neither have I, because it might put me in a bad mood, but it fits the intended pun for the post, and I also wanted to show how it is done from from Delphi.

The mother company of Embarcadero, Idera acquired another company early this year - this time apilayer.com, which provides numerous "simple" cloud-based API services - among these are:

  • IP geolocation and reverse lookup
  • Language detection
  • Mail address validation
  • Phone number validation
  • Flight tracking
  • Currency conversion and rates (including crypto currency)
  • Weather data and forecast
  • News, Headline and Stock apis
  • Conversion PDF and scraping
But go to https://apilayer.com/, and read more about their various layers and tiers for these.

We will in this short demo look at the vatlayer - which does EU VAT stuff.

So I started by signing up for the free tier on https://vatlayer.com/ - which gives you an API access key and access to a dashboard. As always do not share the access key - just saying.

Now you can fire up Delphi, create a new application and either use the REST Debugger or just manually throw in the REST component or create runtime - what you prefer.

I just threw in a edit control and a couple of memos and buttons, as seem above. And then I added an parameter on the RESTClient with the access_key - since I wanted to clear the request parameters on the RESTRequest, but keep the access_key. And set the BaseURL property to http://apilayer.net/api.

I just took two of the methods/resources from https://vatlayer.com/documentation - so the VAT lookup button looks like this:

var
  json: TJSONValue;
begin
  Memo1.Clear;
  RESTRequest1.Method := rmGET;
  RESTRequest1.Resource := 'validate';
  RESTRequest1.Params.Clear;
  RESTRequest1.AddParameter('vat_number', LabeledEdit2.Text, pkGETorPOST);
  RESTRequest1.Execute;
  if RESTResponse1.StatusCode=200 then
  begin
    json := RESTResponse1.JSONValue;
    Memo1.Lines.Add(json.GetValue<string>('company_name'));
    Memo1.Lines.Add(json.GetValue<string>('company_address'));
  end;
end;

..and the VAT rates for HU (since they have a higher VAT rate than DK :D) button looks like this:

var
  json: TJSONValue;
begin
  Memo2.Clear;
  RESTRequest1.Method := rmGET;
  RESTRequest1.Resource := 'rate';
  RESTRequest1.Params.Clear;
  RESTRequest1.AddParameter('country_code', 'HU', pkGETorPOST);
  RESTRequest1.Execute;
  if RESTResponse1.StatusCode=200 then
  begin
    json := RESTResponse1.JSONValue;
    Memo2.Lines.Add(json.Format());
  end;
end;

There nice twists to these - by IP address or get list of rate types - and if combining these services by apilayer.com - I could make a speeding white-van "whistle-blower" mobile app - since all company owned registered vehicles in DK - need to have their VAT numbers on their fleet.

So I could lookup the company and their address, get their phone number by a different api layer - and then call and tell on them - MUHAAHAAAHAA (evil laughter)

..or maybe I should just create something useful and fun.

And the best part about writing this post, I now learned that Denmark has only the second highest VAT rate in EU :D

/Enjoy




Monday, 15 February 2021

Closing in on Modal Jump Lists

- or getting a WM_SYSCOMMAND to a modal dialog.

An idea that initially seemed clever, has been haunting me a bit lately - I did put a modal dialog into a project before the main Application block (Initialize .. Run). Shame on me.

So the code looks similar to like this:

if (TfrmLaunchSetting.Execute = mrOK) then
begin
  Application.Initialize;
  Application.MainFormOnTaskbar := True;
  Application.Title := 'MyApplication';
  Application.CreateForm(TfrmMain, frmMain);
  Application.Run;
end;

and the TFrmLaunchSetting.Execute is just a class function returning the ModalResult, from its ShowModal.

But here comes the issue at hand - the Close Window in the task bars Jump List sends a WM_SYSCOMMAND that goes to the system menu in the main window - but if a modal form is shown the main window is disabled - and in this case I do not even have a main form yet.

So TApplication.HookMainWindow to the rescue - that would enable me to intercept messages sent to the main form - and act upon these.

So in the FormCreate of my modal dialog I hook the my hook function up like this:

Application.HookMainWindow(AppHookFunc);

And on FormDestroy I do the following:

Application.UnHookMainWindow(AppHookFunc);

The AppHookFunc goes as follows:

function TfrmLaunchSetting.AppHookFunc(var Message: TMessage): Boolean;
begin
  Result := False;
  if Message.Msg = WM_SYSCOMMAND then
  begin
    PostMessage(Handle, WM_CLOSE, 0, 0);
    Result := True;
  end;
end;

This way modal dialogs can react to Windows messages that normally be intended for the main form.

There are probably side-effects - but the issue at hand is solved - for now?

BTW: Yesterday was Delphi 26th birthday - I did not forget - but I am still wrapping up the present. Stay tuned.

/Enjoy