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Posted by jpluimers on 2020/11/20
[WayBack] Webcare Amsterdam on Twitter : “Hee Jeroen, jammer dat de auto nu al weg is. Mocht je in het weekend weer een melding willen doen dan kan dat via 14020 of via meldingen.amsterdam.nl. Fijne feestdagen toegewenst! ^TR…”
Buiten kantoortijden melden van foutparkeerders:
–jeroen
Posted in LifeHacker, Power User | Leave a Comment »
Posted by jpluimers on 2020/11/19
https://twitter.com/isotopp/status/1270824610469208072
is a summary of:
[WayBack] Thread by @isotopp: Are you a Developer and understand (Micro-) Services? I am a database person and a bit simple, and I have a genuine Question: When moving to…
Are you a Developer and understand (Micro-) Services? I am a database person and a bit simple, and I have a genuine Question:
When moving to a services architecture, where do the JOINs go?
So you sell stuff, that is you have an orders table o, with an oid, which stores a customer id cid from a customers c table, and an article id aid, from an articles table and a count cnt.customer 17 ordered 3 45’s:
? SELECT cnt
> FROM o JOIN c ON o.cid = c.cid
> AND o.aid = a.aid
> WHERE c.cid = 17;= 3When moving to services, because you are multibillion dollar enterprise, your customers, orders and articles can no longer fit into a single database, and there are other reasons to have an OrderService, CustomerService and ArticleService.You still want to ask something (OrderService?) about the number of 45’s that 17 ordered.
Who do you ask? What does this do to connect the dots? How do you do reporting (“Show me all top 10 articles by country, zipcode digit 1 by week over the last 52w”)?
Do you reimplement join algorithms by hand in application code? Are there supporting tools? Do you reimplement data warehousing aggregations, too?If so, what tooling for reporting does exist, and how does that compare to eg existing tooling for data warehousing?
Some of the reactions on Twitter are below
–jeroen
Posted in Database Development, Development, Software Development, Systems Architecture | Leave a Comment »
Posted by jpluimers on 2020/11/19
Would this be the reason that so many web-sites still use less than half of my screen width?
The 960 Grid System is an effort to streamline web development workflow.
Source: [WayBack] 960 Grid System
Via: [WayBack] windows – What minimum screen size should I assume? – Stack Overflow (where in 2010 for some types of software you had to go for 640×480, many things were still 800×600, but 1024×768 for desktop users was the norm; on the one hand times have changed, but on the other hand not a lot).
Code: [WayBack] GitHub – nathansmith/960-Grid-System: The 960 Grid System is an effort to streamline web development workflow.
Related:
–jeroen
Posted in Development, Software Development, Usability, User Experience (ux), Web Development | Leave a Comment »
Posted by jpluimers on 2020/11/19
Since G+ is down, a lot of interesting questions have vanished.
Luckily I saved some by [WayBack] Jacek Laskowski – Google+ related to Spring4D and dependency injection:
First my Google Groups archival reminder:
Posted in Conference Topics, Conferences, Delphi, Development, Event, Software Development | Leave a Comment »
Posted by jpluimers on 2020/11/18
Checkout github pull requests locally. GitHub Gist: instantly share code, notes, and snippets.
Source: [WayBack] Checkout github pull requests locally · GitHub
The trick is to add one more fetch line to the [remote "origin"] sections in your .git/config files, as in the gist below.
fetch = +refs/pull/*/head:refs/remotes/origin/pr/*
Which reminds me I should read more about that the fetch syntax which is called RefSpec: [WayBack] Git – The Refspec
–jeroen
Posted in Development, DVCS - Distributed Version Control, git, GitHub, Software Development, Source Code Management | Leave a Comment »
Posted by jpluimers on 2020/11/18
One of the protection levels in Delphi is protected. Originally meant for the class itself, that level is also visible to “friends”: anything in the same unit, for example:
unit BusinessLogicUnit; interface type TBusinessLogic = class(TObject) protected Procedure Foo(); // ... public // ... end; implementation // ... end.
You can even access them from outside that unit by using a trick like below.
Some people use the protected section so that unit tests can assess them using the below trick.
Do not do that!
It means anyone can use that trick, often doing more damage than good.
In this case, the trick was abused by a clever programmer that was relatively new to the code base. It resulted in unintended side effects.
unit HackUnit; interface implementation uses BusinessLogicUnit; type TBusinessLogicHack = class(TBusinessLogic); procedure Hack; var Instance: TBusinessLogicHack; begin Instance := TBusinessLogicHack.Create(); try Instance.Foo(); finally Instance.Free(); end; end; end.
Of course you can still access it like below.
It is slightly longer, but more importantly: much better shows the intent and how that intent is accomplished.
unit GoodUsageUnit; interface implementation uses BusinessLogicUnit; type TBusinessLogicDescendant = class(TBusinessLogic) public procedure Foo(); end; procedure TBusinessLogicDescendant.Foo(); begin inherited Foo(); // ... end; procedure Usage; var Instance: TBusinessLogicDescendant; begin Instance := TBusinessLogicDescendant.Create(); try Instance.Foo(); finally Instance.Free(); end; end; end.
–jeroen
Posted in Conference Topics, Conferences, Delphi, Development, Event, Software Development | 1 Comment »
Posted by jpluimers on 2020/11/18
Not that this is bad code, but there are no unit tests for them, and I have seen places in the wild that blindly use it without documenting where it came from and what tested alternatives might be: [WayBack] The Delphi Geek: Using Generics to Manipulate Enumerated Types
The unit itself is down (though there is still a copy on the WayBack machine).
The post itself mentions it is Spring4D-inspired, and since Spring4D already has quite an extensive [WayBack] TEnum<T> implementation covered by unit tests, so that is a logical place to do for.
I might actually document the migration table if I find time for it.
Here is a start so I will only have to insert the blanks
Function Replacement class function Clip(const value: Integer): T; class function Clip(const value: T): T; class function Ensure(const value: Integer; const min, max: T): T; class function Ensure(const value, min, max: T): T; class function FromInt(const value: Integer): T; class function Enum: RangeEnum; static; class function GetValueOrDefault(const value: Integer): T; class function IsValid(const value: Integer): Boolean; class function IsValid(const value: T): Boolean; class function Max: T; static; class function Min: T; static; class function ToInt(const value: T): Integer; class function ToString(const value: T): string;
–jeroen
Posted in Delphi, Development, Software Development | Leave a Comment »
Posted by jpluimers on 2020/11/17
Needs the System.SysConst unit:
procedure RaiseAbstractError(const aClass: TClass; const aMethodName: string); begin // more explanatory than AbstractErrorProc(); raise EAbstractError.CreateFmt('%s: method %s.%s', [SAbstractError, aClass.ClassName, aMethodName]); end;
It uses a TClass typed parameter so you can call it from non-static class methods (using Self as parameter value) in addition to instance methods (using ClassType as parameter value).
–jeroen
Posted in Delphi, Development, Software Development | Leave a Comment »
Posted by jpluimers on 2020/11/17
[WayBack] FeaturesShim is a cool Chocolatey feature that uses ShimGen.
This allows Chocolatey to take only one directory in your search PATH, with a lot of small files, that link to the much larger actual executable files.
ShimGen (like many other parts of Windows and some other parts of Chocolatey) is not open source, but the mechanism is documented.
More information:
–jeroen
Posted in .NET, Development, Power User, Software Development, Windows, Windows Development | Leave a Comment »
Posted by jpluimers on 2020/11/17
From a while ago, from notes even longer ago – around 1994 on DVCLAL the Delphi VCL Access License code which is actually a checking logic for determining the SKU (stock keeping unit) or Delphi license: [WayBack] delphi – What are the list of all possible values for DVCLAL? – Stack Overflow
There is no official documentation on this, so here is something from my notes of 15+ years ago:
The
DVCLALis there to check which SKU of Delphi you are using and it varies per SKU.There are only checks for the Professional (
RPR) and Client/Server (RCS) SKUs:procedure RCS; procedure RPR;If they fail, they call this method:
procedure ALV; begin raise Exception.CreateRes(@SNL); end;where
resourcestring SNL = 'Application is not licensed to use this feature';Depending on the feature matrix and Delphi version, various components call
RPRandRCSin theirCreateconstructors to guarantee a minimum SKU.
Underneath, these RPR and RCS functions call the function GDAL . Their names are historic and got documented around Delphi 2007:
GDAL (Get Delphi Access License)RPR will Restrict to PRofessional license and higherRCS will Restrict to Client/Service license and higherHistorically you had these levels of Delphi editions that could be distinguished this way:
This excludes Starter and Community (which are “just” Personal), Turbo (which was “just” Professional), Architect and Ultimate, which are “just” Client/Server with extra tools.
A few years ago, another answer got added to that question explaining more details:
I am just adding another answer to this question, for all the people who search the for actual DVCLAL (Delphi Visual Component Library Access License) values, as well as some other information for all people who are curious how stuff works.
1) Like Jeroen Wiert Pluimers said, if you want to check for “Professional or higher” or “Enterprise only” inside your Delphi application/library/package/component, you can use
RPR(Require Professional) orRCS(“Require Client/Server”; Client/Server was the name for the Enterprise edition in early Delphi versions) respectively. If the requirement is not met,ALV(Access License Violation) will be called which will raise anExceptionwith the message defined inSysConst.SNL(S Not Licensed). In English:Application is not licensed to use this feature
2) In case you want to check for one specific edition, you can use the output of the function
GDAL(Get Delphi Access License), which is one of the following (AL1sarray):AL1s[0] = $FFFFFFF0; // Standard/Personal edition DVCLAL value AL1s[1] = $FFFFEBF0; // Professional edition DVCLAL value AL1s[2] = $00000000; // Enterprise/ClientServer edition DVCLAL value AL1s[3] = $FFFFFFFF; // DVCLAL resource not existingif the DVCLAL resource has an invalid value,
GDALwill callALVwhich will raise anExceptionwith messageSysConst.SNL.3) In case you want to check the DVCLAL value of a foreign EXE/DLL file (e.g. if you want to write a Resource Editor, decompiler etc), then you’ll have to query the DVCLAL resource directly.
There are only three official values:
Standard: 23 78 5D 23 B6 A5 F3 19 43 F3 40 02 26 D1 11 C7 Professional: A2 8C DF 98 7B 3C 3A 79 26 71 3F 09 0F 2A 25 17 Enterprise: 26 3D 4F 38 C2 82 37 B8 F3 24 42 03 17 9B 3A 834) Just for fun: If you solve the formula
0 = (ROR(a,15) xor a) xor (ROR(b,10) xor b) xor (ROR(c,5) xor c) xor (AL1 xor AL2)you can define any DVCLAL value (tuple a, b, c, d) you want! (AL1andAL2are the values in theAL1sandAL2sarrays which describe the desired Delphi edition;RORis rotate right through carry)For example, here are alternative DVCLALs which work too:
Standard: 00 00 00 00 00 00 00 00 9B 70 0C 66 6B 8F F3 99 Professional: 00 00 00 00 00 00 00 00 9A DB 73 0F 6A 30 8C F0 Enterprise: 00 00 00 00 00 00 00 00 D8 B2 48 11 D8 B2 48 11To validate a DVCLAL, you calculate
AL1 := DVCLAL[0] xor DVCLAL[1] xor DVCLAL[2] xor DVCLAL[3]; AL2 := ROR(DVCLAL[0],15) xor ROR(DVCLAL[1],10) xor ROR(DVCLAL[2],5) xor DVCLAL[3];and look up AL1 and AL2 in the array
AL1sandAL2s,This way you can disguise the edition you have used a little.
5) In the meantime, an official documentation, at least for the functions GDAL, RPR and RCS, has been published.
6) Of course, everything works for C++ Builder, too.
In the mean time, new posts explaining bits of DVCLAL related resources (like PACKAGEINFO and CHARTABLE) and the TPF0 form/datamodule resource have appeared, of which this is a selection:
—jeroen
Posted in Conference Topics, Conferences, Delphi, Development, Event, History, Software Development, Undocumented Delphi | Leave a Comment »
The Wiert Corner - irregular stream of stuff 