The DDEClient class. Use this class to create and manage a connection to a service/topic. To get classbacks subclass DDEClient and overwrite callback.
| 124 | RuntimeError.__init__(self, "%s (err=%s)" % (msg, hex(DDE.GetLastError(idInst)))) |
| 125 | |
| 126 | class DDEClient(object): |
| 127 | """The DDEClient class. |
| 128 | |
| 129 | Use this class to create and manage a connection to a service/topic. To get |
| 130 | classbacks subclass DDEClient and overwrite callback.""" |
| 131 | |
| 132 | def __init__(self, service, topic): |
| 133 | """Create a connection to a service/topic.""" |
| 134 | from ctypes import byref |
| 135 | |
| 136 | self._idInst = DWORD(0) |
| 137 | self._hConv = HCONV() |
| 138 | |
| 139 | self._callback = DDECALLBACK(self._callback) |
| 140 | res = DDE.Initialize(byref(self._idInst), self._callback, 0x00000010, 0) |
| 141 | if res != DMLERR_NO_ERROR: |
| 142 | raise DDEError("Unable to register with DDEML (err=%s)" % hex(res)) |
| 143 | |
| 144 | hszService = DDE.CreateStringHandle(self._idInst, service, 1200) |
| 145 | hszTopic = DDE.CreateStringHandle(self._idInst, topic, 1200) |
| 146 | self._hConv = DDE.Connect(self._idInst, hszService, hszTopic, PCONVCONTEXT()) |
| 147 | DDE.FreeStringHandle(self._idInst, hszTopic) |
| 148 | DDE.FreeStringHandle(self._idInst, hszService) |
| 149 | if not self._hConv: |
| 150 | raise DDEError("Unable to establish a conversation with server", self._idInst) |
| 151 | |
| 152 | def __del__(self): |
| 153 | """Cleanup any active connections.""" |
| 154 | if self._hConv: |
| 155 | DDE.Disconnect(self._hConv) |
| 156 | if self._idInst: |
| 157 | DDE.Uninitialize(self._idInst) |
| 158 | |
| 159 | def advise(self, item, stop=False): |
| 160 | """Request updates when DDE data changes.""" |
| 161 | from ctypes import byref |
| 162 | |
| 163 | hszItem = DDE.CreateStringHandle(self._idInst, item, 1200) |
| 164 | hDdeData = DDE.ClientTransaction(LPBYTE(), 0, self._hConv, hszItem, CF_TEXT, XTYP_ADVSTOP if stop else XTYP_ADVSTART, TIMEOUT_ASYNC, LPDWORD()) |
| 165 | DDE.FreeStringHandle(self._idInst, hszItem) |
| 166 | if not hDdeData: |
| 167 | raise DDEError("Unable to %s advise" % ("stop" if stop else "start"), self._idInst) |
| 168 | DDE.FreeDataHandle(hDdeData) |
| 169 | |
| 170 | def execute(self, command, timeout=5000): |
| 171 | """Execute a DDE command.""" |
| 172 | pData = c_char_p(command) |
| 173 | cbData = DWORD(len(command) + 1) |
| 174 | hDdeData = DDE.ClientTransaction(pData, cbData, self._hConv, HSZ(), CF_TEXT, XTYP_EXECUTE, timeout, LPDWORD()) |
| 175 | if not hDdeData: |
| 176 | raise DDEError("Unable to send command", self._idInst) |
| 177 | DDE.FreeDataHandle(hDdeData) |
| 178 | |
| 179 | def request(self, item, timeout=5000): |
| 180 | """Request data from DDE service.""" |
| 181 | from ctypes import byref |
| 182 | |
| 183 | hszItem = DDE.CreateStringHandle(self._idInst, item, 1200) |