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Help / WLanguage / WLanguage functions / Communication / Sockets
  • Number of transmitted bytes
  • Communication with robots or with non-WINDEV applications
  • Transmission between two workstations using different string formats (Unicode and ANSI)
  • Required permissions
WINDEV
WindowsLinuxJavaReports and QueriesUser code (UMC)
WEBDEV
WindowsLinuxPHPWEBDEV - Browser code
WINDEV Mobile
AndroidAndroid Widget iPhone/iPadIOS WidgetApple WatchMac Catalyst
Others
Stored procedures
Retrieves a message sent by another socket. This function can be used on a client computer or on a server.
Remarks:
  • Socket UDP: Since UDP is an "unconnected" protocol, WINDEV records the IP address and port of the machine that sent the message when retrieving it.. This information is returned by SocketClientInfo.
  • Socket SSL: SocketRead can be used with SSL sockets.
Reminder A socket is a communication resource used by applications to communicate from one machine to another, regardless of the type of network.
WINDEVReports and QueriesJavaUser code (UMC)
// Add received messages in a Table control
TableAdd(TABLE_Table1, "1" + TAB + SocketRead("Server", False) + ...
TAB + SocketClientInfo("server", SocketAddress) + ...
TAB + SocketClientInfo("server", SocketPort))
WEBDEV - Server codePHPAjax
WHILE SocketExist("MySocket") = True
sMsg is string = SocketRead("MySocket", True)
IF sMsg <> "" THEN
ListAdd(LIST_Messages, Now() + " " + sMsg)
END
END
Syntax
<Result> = SocketRead(<Socket name> [, <Undefined wait> [, <Maximum timeout> [, <Maximum number of bytes> [, <IncomingData delay>]]]])
<Result>: Buffer or character string
  • Message read.
  • Empty buffer or empty string ("") if no message was received.
<Socket name>: Character string
Name of the socket that received the message.
In the WINDEV applications:
WINDEV Warning: the socket name is "case-sensitive".
<Undefined wait>: Optional boolean
  • True (default): waiting indefinitely for a customer message.
  • False: wait until <Maximum wait>.
<Maximum timeout>: Optional integer or optional Duration
Maximum timeout (in milliseconds) of a client message if the undefined wait is set to False. This parameter can correspond to:
  • an integer representing the number of milliseconds,
  • a Duration variable,
  • the duration in a readable format (e.g., 1 s or 10 ms).
By default, this timeout is set to 1000 milliseconds (1 second).
<Maximum number of bytes>: Optional integer
Maximum number of characters that can be transmitted. The number of characters received is not guaranteed.
This parameter is taken into account only if the SocketNoEndTag constant is specified in SocketChangeTransmissionMode. Otherwise, this parameter is ignored.
This parameter is set to 4096 bytes by default.
<IncomingData delay>: Optional integer
New in version 2025
Maximum waiting time without IncomingData. If data is received during this time, the delay is reset.
AndroidAndroid Widget JavaPHP This parameter is not available.
Remarks
WINDEVWEBDEV - Server codeReports and QueriesJavaUser code (UMC)

Number of transmitted bytes

<Maximum number of bytes> corresponds to the maximum number of characters that can be transmitted. The number of characters received is not guaranteed.
SocketRead reads a network frame and returns it immediately, without transforming it. However, the size of a network frame depends on several factors (network setting, speed and traffic on the network, ...).
SocketWrite sends (if possible) the buffer passed as parameter in a single frame. If this frame is not accepted by the network, the buffer can be divided into several frames (or the other way round, the network can merge the messages into a single frame to optimize the bandwidth).
To respect the integrity of the transmitted messages, you must use a native WINDEV and WEBDEV protocol (with the SocketSizeAtBeginning or SocketEndTag constants of SocketChangeTransmissionMode) or you must implement a specific protocol.

Communication with robots or with non-WINDEV applications

To simplify the exchanges of data by socket, a transmission mode is initialized by default.
For a communication with an external module (non-WINDEV application, robot, ...), this transmission mode can prevent the communications from operating properly.
The SocketChangeTransmissionMode function is used to change this transmission mode: the constant SocketSansMarqueurFin constant is used to leave the read and write patterns unchanged.

Transmission between two workstations using different string formats (Unicode and ANSI)

When transmitting messages between two stations using a different string format (e.g. ANSI and Unicode), certain conversions may be necessary. These conversions can be made by AnsiToUnicode and UnicodeToAnsi.
AndroidAndroid Widget

Required permissions

This function changes the permissions required by the application.
Permission required: INTERNET
This permission allows the applications to open the network sockets.
Business / UI classification: Business Logic
Component: wd300com.dll
Minimum version required
  • Version 9
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Last update: 11/26/2024

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