docs/latex/wx/ipcclint.tex

   1 \section{\class{wxClient}}\label{wxddeclient}
   2
   3 A wxClient object represents the client part of a client-server
   4 DDE-like (Dynamic Data Exchange) conversation. The actual
   5 DDE-based implementation using wxDDEClient is available on Windows
   6 only, but a platform-independent, socket-based version of this
   7 API is available using wxTCPClient, which has the same API.
   8
   9 To create a client which can communicate with a suitable server,
  10 you need to derive a class from wxConnection and another from
  11 wxClient. The custom wxConnection class will intercept
  12 communications in a `conversation' with a server, and the custom
  13 wxClient is required so that a user-overridden
  14 \helpref{wxClient::OnMakeConnection}{wxddeclientonmakeconnection}
  15 member can return a wxConnection of the required class, when a
  16 connection is made. Look at the IPC sample and the
  17 \helpref{Interprocess communications overview}{ipcoverview} for
  18 an example of how to do this.
  19
  20 \wxheading{Derived from}
  21
  22 wxClientBase\\
  23 \helpref{wxObject}{wxobject}
  24
  25 \wxheading{Include files}
  26
  27 <wx/ipc.h>
  28
  29 \wxheading{See also}
  30
  31 \helpref{wxServer}{wxddeserver},
  32 \helpref{wxConnection}{wxddeconnection}, \helpref{Interprocess communications overview}{ipcoverview}
  33
  34 \latexignore{\rtfignore{\wxheading{Members}}}
  35
  36 \membersection{wxClient::wxClient}
  37
  38 \func{}{wxClient}{\void}
  39
  40 Constructs a client object.
  41
  42 \membersection{wxClient::MakeConnection}\label{wxddeclientmakeconnection}
  43
  44 \func{wxConnectionBase *}{MakeConnection}{\param{const wxString\& }{host}, \param{const wxString\& }{service}, \param{const wxString\& }{topic}}
  45
  46 Tries to make a connection with a server by host (machine name
  47 under UNIX - use 'localhost' for same machine; ignored when using
  48 native DDE in Windows), service name and topic string. If the
  49 server allows a connection, a wxConnection object will be
  50 returned. The type of wxConnection returned can be altered by
  51 overriding the
  52 \helpref{wxClient::OnMakeConnection}{wxddeclientonmakeconnection}
  53 member to return your own derived connection object.
  54
  55 Under Unix, the service name may be either an integer port
  56 identifier in which case an Internet domain socket will be used
  57 for the communications, or a valid file name (which shouldn't
  58 exist and will be deleted afterwards) in which case a Unix domain
  59 socket is created.
  60
  61 {\bf SECURITY NOTE:} Using Internet domain sockets if extremely
  62 insecure for IPC as there is absolutely no access control for
  63 them, use Unix domain sockets whenever possible!
  64
  65 \membersection{wxClient::OnMakeConnection}\label{wxddeclientonmakeconnection}
  66
  67 \func{wxConnectionBase *}{OnMakeConnection}{\void}
  68
  69 Called by \helpref{wxClient::MakeConnection}{wxddeclientmakeconnection}, by
  70 default this simply returns a new wxConnection object. Override
  71 this method to return a wxConnection descendant customised for the
  72 application.
  73
  74 The advantage of deriving your own connection class is that it
  75 will enable you to intercept messages initiated by the server,
  76 such as \helpref{wxConnection::OnAdvise}{wxddeconnectiononadvise}. You
  77 may also want to store application-specific data in instances of
  78 the new class.
  79
  80 \membersection{wxClient::ValidHost}
  81
  82 \func{bool}{ValidHost}{\param{const wxString\& }{host}}
  83
  84 Returns true if this is a valid host name, false otherwise. This always
  85 returns true under MS Windows.
  86