Delphi Programming Tips & Tricks

In the previous article, we learned that native Delphi serialization is based around published properties, and that other kinds of serialization, like field-based serialization, don't fit well with the Delphi model. Photo: Gary Todd from Xinzheng, China, PDM-owner, via Wikimedia Commons, https://commons.wikimedia.org/wiki/File:Colosseum_(48412957912).jpg We have also learned that property-based serialization has some limitations and that it does not have out-of-the-box support for the serialization of records, arrays, or indexed properties, and you can only serialize collections defined as TCollection , whose items are descendants of TCollectionItem . While serialization as a concept is widely used to convert any kind of objects into various storage formats, the main purpose of the Delphi serialization model being built on top of published properties and descendants of TComponent was to serialize the user interface and data modules. This is where the original type limitati...

Join me this Thursday, Apr 22, 2021 5:00 PM - 6:00 PM CEST for a live Q/A session about Delphi memory management. See you!  Register for webinar: https://register.gotowebinar.com/register/474961949731996432 Book information: https://dalija.prasnikar.info/delphimm  

While different OOP languages share some common principles and many coding patterns will be the same or at least fairly similar, there are also some significant differences that can make some commonly used patterns from one language quite unsuitable in another—and if used, such patterns can cause a lot of trouble. Photo: Gary Todd from Xinzheng, China, PDM-owner, via Wikimedia Commons, https://commons.wikimedia.org/wiki/File:Colosseum_(48412957912).jpg One such pattern can be found in their serialization approaches. In Java, object serialization is performed on fields. In Delphi, the convention is to serialize published properties. That is also the original purpose of the published visibility specifier. Delphi also supports defining custom properties in TPersistent descendants, via DefineProperties method. When it comes to what kind of properties Delphi can serialize out of the box, there are some limitations, so you cannot serialize records, arrays, or indexed properties, and ...