Refactoring: Extract method

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In SAP’s world, ABAP code will forever stay wherever you leave it.

On one given day, Manuel did something badly because he was on a rush or didn’t know any better. One year later António is asked to make a small change to it. António spots Manuel’s mess but he doesn’t improve it because, for some reasons, in SAP, changing something which is working, even if it’s badly implemented, is a tabu. Instead, António will add his code to the existing one and forget about it.

This attitude, when adopted by everyone, contributes to an inevitable erosion of the system’s code which, some years later, becomes unmanageable. And still, that’s the rule.

The way I see it, this is wrong and goes against the customer’s best interests. Actually, even if the customer doesn’t want me to modify old code because it’s working… I still do it. Who is he to tell me how to program?

A comment on comments

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We learn in school that all code should have comments. Then, in real life, we find that not everyone was paying attention to what was said in school. As a consequence, most code is obscure and without proper comments.

I was always careful to comment every relevant step of my code, specially the parts which are obscure or not self-explanatory.

But since I recently read Uncle Bob’s Clean Code , my opinion on this changed. Today I believe that the less comments the better. And yet, I don’t see this as contradictory to what I used to think.

The multiple clocks of your SAP system

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Even though you look at an SAP system as a whole, it is composed by several distinct and interconnected parts. There is a small standard program which checks if each part’s clock is correct and synchronised.

It probably won’t be of much use for your daily work. Still, it’s an interesting curiosity.

ABAP, the lobotomizer

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João studies Computer Science at his College where he learns Java, polymorphism, encapsulation and a lot of other programming techniques and best practices. When he graduates, he decides to join a company to work in SAP. At the introduction training which his new company offers, the first thing he learns is how to make a program in ABAP. Here’s how they teach it:

_“Go to transaction SE38, create program ZJOAO and then create includes ZJOAO_TOP, ZJOAO_FRM and ZJOAO_SEL. You declare all variables in _TOP, the selection screen you put in _SEL and all the FORMS must go into FRM. Then write START-OF-SELECTION and under that put all the SELECTs and finally write END-OF-SELECTION and there you show the results in an ALV. It’s that simple. Welcome to ABAP.”

Inject ABAP commands into a productive system

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The view below shows how simple it is to create the conditions to inject ABAP commands into programs in a productive system.

I considered whether to publish this. But, as it already happened in the past, I believe it is better for this to be known because it is very important for system administrators to be aware of this so they can protect their systems against this threat.

Thank you Ricardo Monteiro for the tip.

Transport a local table with its maintenance screens

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Some time ago you created a table and its maintenance screens as local objects.

When, later, you regret it and decide to transport the table, how will you be able to also transport the maintenance screens?

Transporting the maintenance screens function group together with the table is not enough.

Test a sequence of function modules in SE37

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I was sure I had already posted about this before but I can’t find it so here it goes (again?).

Some function modules save global data which must then be used by another function module belonging to the same function group. So, if you need to test them, they must run in sequence inside the same transaction.

Everybody knows you can use SE37 to test a function module. What few people know is that you can also use SE37 to test a sequence of function modules inside the same transaction. Those who don’t know this end up creating a small program to call those functions in sequence and that’s also ok. But here’s how you can avoid that.

Test function module with data loaded from a file

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Transaction SE37 lets you test function modules. Sometimes these function modules use tables. And sometimes you need to load these tables with a lot of data records. But the only way to do it is manually. Or maybe not…

Here’s a trick to do it using a file.

Have extra control over your selection screen

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The PARAMETERS and SELECT-OPTIONS already have some configuration options. But sometimes you need more control, more customising. Interestingly, although it’s not simple nor obvious, it can be done through a standard function module.

Debug on a user without debug permissions

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In a well protected system, normal users don’t have debug permissions. Very often, this makes it harder for ABAP programmers to help solve the users’ problems, not being able to debug directly in their session.

But there is a legit, albeit obscure, work-around for this problem.