Mastering PowerBuilder

Building the Server Application

If you haven't created a library for the server application, create a library product-server.pbl and create an application pms in this library. Then copy all the DataWindows from the product.pbl into this library. This is needed because, we are using DataStores on the server. Then copy the user object ncst_product_master—you don't have to copy proxy object.

Create a window w_pms_server as shown below. Name CommandButtons as cb_start_or_stop_server, cb_server_options, cb_refresh and cb_exit respectively from left to right. Below is a DataWindow dw_users. There is another DataWindow dw_options right behind the dw_users.

Paint a tabular/Grid presentation style, external data source DataWindow d_users with the following structure

Name	Type	Length
userid	String	16
connecttime	datetime
busy	String	3
lastcalltime	datetime
callcount	long
clientid	String	16
location	String	16
connectuserid	String	16
connectstring	String	100

Paint a FreeForm presentation style, external data source DataWindow d_server_options with the following structure.

Name	Type	Length
Application	String	30
driver	String	20
location	String	60
opt_bufsize	number
opt_ThreadPooling	number
opt_maxListeningThreads	number
opt_nodelay	number
opt_rawdata	number
trace_console	number
trace_level	number
trace_log	String	60
trace_objectcalls	number
trace_objectlife	number
trace_dumpargs	number
trace_all	number

To make the server to listen to the clients, we need to do four things.

• Declare a variable of type transport object that is available throughout the server application.
• Create an instance of the transport object
• Populate transport object with proper values
• Ask the server to listen to clients.

First let's define registry entries and set them with proper default values. Select Start > Run menu option from the taskbar and run REGEDIT command and define HKEY_LOCAL_MACHINE\SOFTWARE\PMS key in the registry. Then create the following sub-keys and populate them as shown below:

Key/ String Value in the Registry	SubKey	Value
Application		PMSServer
Driver		WinSock
Location		LocalHost
Options
	BufSize	100
	MaxRetry	5
	NoDelay	1
	RawData	1
	TimeOut	60
Trace
	Console	1
	Log	C:\workdir\pmsserver.log
	ObjectCalls	1
	ObjectLife	1
	DumpArgs	1
	All	1

Declare the following instance variables.

CONSTANT STRING IS_REGKEY = 'HKEY_LOCAL_MACHINE\Software\PMS' CONSTANT STRING IS_REGKEY_TRACE = IS_REGKEY + '\TRACE' CONSTANT STRING IS_REGKEY_OPTIONS = IS_REGKEY + '\OPTIONS'

Declare a global transport object. The reason we are declaring it as a global is, we need it through out the server application.

transport gtrp_Transport

Let us create the transport object in the w_pms_server window's open event.

// Event: Open // Object: w_pms_server window gtrp_transport = CREATE transport

We will be defining four functions.

of_SetTransportObjectValues – Reads values from registry and sets the transport object.

of_Disconnect—Disconnects the specified client from the server.

of_GetServerOptions()—Reads server options and loads into the DataWindow.

of_SetServerOptions()—Reads the server options from the DataWindow and saves in the registry.

Declare of_SetTransportObjectValues() function at w_pms_server as shown below.

// Function: of_SetTransportObjectValues() at w_pms_server window. // Access: Private // Returns: Integer // Arguments: None String ls_str, ls_str1 RegistryGet(IS_REGKEY,'Driver', ls_str) gtrp_Transport.driver = ls_str RegistryGet(IS_REGKEY,'Application', ls_str) gtrp_Transport.application = ls_str RegistryGet(IS_REGKEY,'Location', ls_str) gtrp_Transport.location = ls_str RegistryGet(IS_REGKEY_OPTIONS,'BufSize', ls_str) ls_str1 = 'BufSize=' + ls_str RegistryGet(IS_REGKEY_OPTIONS,'MaxRetry', ls_str) ls_str1 += ',MaxRetry=' + ls_str RegistryGet(IS_REGKEY_OPTIONS,'NoDelay', ls_str) ls_str1 += ',NoDelay=' + ls_str RegistryGet(IS_REGKEY_OPTIONS,'RawData', ls_str) ls_str1 += ',RawData=' + ls_str RegistryGet(IS_REGKEY_OPTIONS,'TimeOut', ls_str) gtrp_Transport.Options = ls_str1 RegistryGet(IS_REGKEY_TRACE,'Console', ls_str) ls_str1 = 'Console=' + ls_str RegistryGet(IS_REGKEY_TRACE,'Log', ls_str) ls_str1 += ",Log='" + ls_str + "'" RegistryGet(IS_REGKEY_TRACE,'ObjectCalls', ls_str) ls_str1 += ',ObjectCalls=' + ls_str RegistryGet(IS_REGKEY_TRACE,'ObjectLife', ls_str) ls_str1 += ',ObjectLife=' + ls_str RegistryGet(IS_REGKEY_TRACE,'DumpArgs', ls_str) ls_str1 += ',DumpArgs=' + ls_str RegistryGet(IS_REGKEY_TRACE,'All', ls_str) ls_str1 += ',All=' + ls_str gtrp_Transport.Trace = ls_str1 Return 0

In the above function, we are reading the registry entries and loading into the global transport object variable.

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