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Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for August 18th, 2020

Nick Hodges on SOLID in TypeScript using Angular

Posted by jpluimers on 2020/08/18

For my link archive: after a long history of Delphi programming, Nick Hodges did a

SOLID series with TypeScript using Angular

They explain these SOLID – Wikipedia concepts:

  1. Single responsibility principle – Wikipedia
  2. Open–closed principle – Wikipedia
  3. Liskov substitution principle – Wikipedia
  4. Interface segregation principle – Wikipedia
  5. Dependency inversion principle – Wikipedia

After that, he did a series on:

[WayBack] Angular 101 – Angles and Types

More Angular and TypeScript

Since Nick likes that combination so much:

and his TypeScript series start:

and what started as a trilogy in 5 parts of his [WayBack] Angular 101 – Angles and Types became much longer:


DIID update

Nick also updated the public repository with the changes that did make it in his Dependency injection in Delphi book earlier:


Read the rest of this entry »

Posted in Design Patterns, Development, Scripting, Software Development, TypeScript | Leave a Comment »

In the series “avoid Variants when coding in Delphi”: the comparison operator

Posted by jpluimers on 2020/08/18

For Variant types, the = comparison operator in Delphi maps to the VarCompareValue in the Variants unit.

That function fails to handle various comparisons and for some it knows it can handle raises a VarInvalidOp through various code paths (like CheckType) to VarInvalidOp because the implementation limits itself to varEmpty..varUInt64, which I think means that these are unsupported:

  • varRecord
  • varStrArg
  • varObject
  • varUStrArg
  • varString
  • varAny
  • varUString
  • varArray
  • varByRef

This fails when using the = operator:

What is this code supposed to do, if v1 and v2 are variant arrays with the same content?

if v1 = v2 then
  WriteLn('not equal');

Spring4d has a function SameValue in the Spring.pas unit which handles more cases, at least the case when both operands are arrays having the same content.

Source: [WayBack] I think I may have mentioned that I hate Variants: What is this code supposed to do, if v1 and v2 are variant arrays with the same content? if v1 = v2… – Thomas Mueller (dummzeuch) – Google+

Thanks to Thomas Mueller and Stefan Glienke for this.


Posted in Delphi, Development, Software Development | Leave a Comment »

Some PlantUML links I needed for complex component diagram editing

Posted by jpluimers on 2020/08/18

A while ago, I had to create a bit more complex component diagrams than the simple ones I used to create in PlantUML.

Some links that helped me:

UML2 style examples for skinparam that are equivalent:

skinparam component {
  Style uml2
skinparam {
  componentStyle uml2

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Posted in Development, Diagram, PlantUML, Software Development, UML | Leave a Comment »

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