SAP TEXT ENVIRONM - Guide

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GUIDELINE 6.55

Text Environment

ABAP_BACKGROUND
The text environment is part of the runtime environment of an ABAP program and is made up of a language, a locale and a system codepage. All programs in an internal session have a common text environment.
As a default, the text environment of an internal session is determined by the logon language and can be set programmatically by the statement SET LOCALE. The language of the current text environment is contained in the system field sy-langu.

ABAP_RULE
If possible, do not switch the text environment within the coding
Set the statement SET LOCALE in exceptional cases only, and reverse any text environment switches in good time.

ABAP_DETAILS
ABAP-coded services usually expect the text environment to be specified by the current user's logon language. The services are not designed to handle text environment switches of internal sessions within the coding.
If you have to switch the text environment for a specific service due to the following exceptions, you must do so only temporarily. This means that you must reset a switched text environment within the same program context, in order to prevent unexpected behavior in other programs within the same internal session.

Exception
Switching the text environment within the coding may be necessary in the following cases:

For processing texts that were not authored in the logon language, for example when sorting with SORT ... AS TEXT, or when enforcing characters with TRANSLATE or an equivalent predefined function

For accessing external files

Bad example
The following source text shows a text environment switch within a method, where the text environment is not reset before exiting the method. This poses the danger of continuing within the wrong text environment after returning from the method. METHOD ...
SET LOCALE LANGUAGE ...
...
ENDMETHOD.

Good example
The following source text shows a text environment switch within a method, where the text environment is reset to its original state before exiting the method. METHOD ...
DATA env_lang TYPE tcp0c-langu.
GET LOCALE LANGUAGE env_lang.
SET LOCALE LANGUAGE ...
...
SET LOCALE LANGUAGE env_lang.
ENDMETHOD.