I read a lot the documentation, this forum and made my own experiences with various OOP structures, like advanced records, objects, classes. Over time I gathered a lot of information, and put it all in one document originally for myself, but now I share it hereby.
It is rather long, but I tried to cover everything that caused a problem to me and what was not obvious to find in the documentations.
I am glad if I can help anyone with it, and also would be very thankful to those who know more about these topics and take the time to read it and provide feedback.
Please feel free to write any error you find, any comment you have or any topic that should be added.
For the time being it will be here, so if you want to share, please distribute this link rather than a copy of the document. I expect it to be updated, so a copy is a dead-end with a half ready document.
P.S. It was written as.odt originally (55Kb), but it could not be attached, so I saved as .docx (47Kb). Neither could upload that. Tried to save as .doc or .pdf (250Kb) and even renaming the smaller .docx to .doc, but none of them worked. For the three latter cases the form to Post simply did nothing. Any idea, what can be wrong?