Requests to change language and character set

When a client connects to an Open Server, it specifies a language and character set in the login record. Open Server uses this information to set up a CS_LOCALE and character set conversion routines for the client thread.

Open Server handles this automatically; an Open Server application does not need to take any steps to handle localized clients at login time.

However, after logging in, clients can change their language and character set. If a client sends a request to change its language or character set, the Open Server application must make the requested changes in the client thread’s CS_LOCALE structure.

A client can request a change of language or character set in two ways:

Using a language-based option command sent with ct_command. This type of command triggers a SRV_LANGUAGE event, so the Open Server application will process the request inside a SRV_LANGUAGE event handler.
Using an option command sent with ct_options. This type of command triggers a SRV_OPTION event, so the Open Server application will process the request inside a SRV_OPTION event handler.

In both cases, the Open Server application responds by:

Setting up a CS_LOCALE structure with the new language or character set
Calling the srv_thread_props routine with property set to SRV_T_LOCALE to change the language or character set for the thread connection

Table 2-22 describes how to change the language or character set for a client thread:

**Table 2-22: Changing the language or character set**
Step	Application step	Purpose	Details
1	Call cs_loc_alloc.	Allocate a CS_LOCALE structure.	This call copies the Open Server application context’s current localization information into the new CS_LOCALE structure.
2	Call srv_thread_props(GET) with property as SRV_T_LOCALE.	Copy the client thread’s existing localization values into the new CS_LOCALE structure.
3	Call cs_locale.	Overwrite the CS_LOCALE structure with the requested language or character set.	For more information about this process, see “Localizing a CS_CONTEXT structure”.
4	Call srv_thread_props(SET) with property as SRV_T_LOCALE.	Set up the client thread with the new language or character set.
5	Optionally, call cs_loc_drop.	Deallocate the CS_LOCALE structure.	An application can reuse the CS_LOCALE structure before deallocating it. If necessary, the application can call cs_locale to change the localization values in the structure before reusing it.