Annotation of libwww/Library/src/HTAlert.html, revision 2.50
2.6 timbl 1: <HTML>
2: <HEAD>
2.46 frystyk 3: <TITLE>W3C Sample Code Library libwww Library Alert Class</TITLE>
2.39 frystyk 4: <!-- Changed by: Henrik Frystyk Nielsen, 13-Jul-1996 -->
2.6 timbl 5: </HEAD>
6: <BODY>
2.38 frystyk 7: <H1>
8: The Alert Class
9: </H1>
2.12 frystyk 10: <PRE>
11: /*
2.18 frystyk 12: ** (c) COPYRIGHT MIT 1995.
2.12 frystyk 13: ** Please first read the full copyright statement in the file COPYRIGH.
14: */
15: </PRE>
2.38 frystyk 16: <P>
17: The Alert class defines a set of methods to be used by libwww to be used
18: for passing prompts and message to a user. In order to maintain the Library
19: core application independent and natural language independent, libwww does
20: not know how to communicate with a <I>user</I>. Note here that a <I>user</I>
21: is a somewhat abstract notion for something that can receive a message
22: or prompt from the Library. This can for example be a person, but is may
23: also be handled automatically by a robot or a client receiving a response
24: from a HTTP server.
25: <P>
26: Libwww has a set of <B>opcodes</B> that classifies the nature of the message,
27: for example that it is a question that must be confirmed in order to continue
28: a request or simply a progress notification. The application can register
29: a method for any number of the defined opcodes - in case the Library has
30: a message for an opcode that does not have a method associated, the message
31: is ignored. You can also globally disable any message send from the Library.
32: <P>
33: <B>Note</B>: The library <B>core</B> does not define any message or dialog
34: methods - they are all considered part of the application. The library comes
35: with a <A HREF="HTDialog.html">default set of methods</A> which can be initiated
36: using the function <CODE>HTAlertInit()</CODE> in <A HREF="HTInit.html">HTInit
37: module</A>
38: <P>
39: This module is implemented by <A HREF="HTAlert.c">HTAlert.c</A>, and it is
2.50 ! frystyk 40: a part of the <A HREF="http://www.w3.org/Library/"> W3C Sample Code
2.38 frystyk 41: Library</A>.
2.11 frystyk 42: <PRE>
2.12 frystyk 43: #ifndef HTALERT_H
44: #define HTALERT_H
2.17 frystyk 45:
2.27 frystyk 46: #include "HTReq.h"
2.11 frystyk 47: </PRE>
2.38 frystyk 48: <H2>
49: Message Opcodes and Messages
50: </H2>
51: <P>
52: The callback functions are defined as a generic callback where the caller
53: can pass a set of input parameters and the callee can return a set of outptu
54: parameters. Also note that all the <CODE>*_PROG_*</CODE> opcodes are a subset
55: of <CODE>HT_A_PROGRESS</CODE>. This means that you easily can register a
56: callback for <EM>all</EM> progress reports.
2.32 frystyk 57: <PRE>
58: typedef enum _HTAlertOpcode {
59: HT_PROG_DNS = 0x1, /* Doing DNS resolution */
60: HT_PROG_CONNECT = 0x2, /* Connecting Active */
61: HT_PROG_ACCEPT = 0x4, /* Connecting Passive */
62: HT_PROG_READ = 0x8, /* Read data */
63: HT_PROG_WRITE = 0x10, /* Write data */
64: HT_PROG_DONE = 0x20, /* Request finished */
65: HT_PROG_WAIT = 0x40, /* Wait for socket */
2.44 frystyk 66: HT_PROG_GC = 0x80, /* Cache garbage collecting */
2.32 frystyk 67: HT_A_PROGRESS = 0xFF, /* Send a progress report - no reply */
68:
69: /* First word are reserved for progresss notifications */
70:
71: HT_A_MESSAGE = 0x1<<8, /* Send a message - no reply */
72: HT_A_CONFIRM = 0x2<<8, /* Want YES or NO back */
73: HT_A_PROMPT = 0x4<<8, /* Want full dialog */
74: HT_A_SECRET = 0x8<<8, /* Secret dialog (e.g. password) */
75: HT_A_USER_PW = 0x10<<8 /* Atomic userid and password */
76: } HTAlertOpcode;
2.15 frystyk 77:
2.32 frystyk 78: typedef struct _HTAlertPar HTAlertPar;
2.8 luotonen 79:
2.32 frystyk 80: typedef BOOL HTAlertCallback (HTRequest * request, HTAlertOpcode op,
2.35 frystyk 81: int msgnum, const char * dfault, void * input,
2.32 frystyk 82: HTAlertPar * reply);
2.6 timbl 83: </PRE>
2.38 frystyk 84: <P>
85: If you don't expect any return values then <CODE>reply</CODE> can be NULL.
86: The return value of the callback function can be used to indicate confirmation
87: on a prompt (Yes or No).
88: <H3>
89: String Messages
90: </H3>
91: <P>
92: This is an enumerated list of messages that can be converted into a string
93: table etc.
2.15 frystyk 94: <PRE>
2.32 frystyk 95: typedef enum _HTAlertMsg {
96: HT_MSG_NULL = -1,
97: HT_MSG_UID = 0,
2.43 frystyk 98: HT_MSG_PROXY_UID,
99: HT_MSG_FTP_UID,
2.32 frystyk 100: HT_MSG_PW,
101: HT_MSG_FILENAME,
102: HT_MSG_ACCOUNT,
103: HT_MSG_METHOD,
104: HT_MSG_MOVED,
105: HT_MSG_RULES,
2.39 frystyk 106: HT_MSG_FILE_REPLACE,
107: HT_MSG_RETRY_AUTHENTICATION,
2.41 frystyk 108: HT_MSG_RETRY_PROXY_AUTH,
2.40 frystyk 109: HT_MSG_REDO,
110: HT_MSG_BIG_PUT,
111: HT_MSG_SOURCE_MOVED,
112: HT_MSG_DESTINATION_MOVED,
2.41 frystyk 113: HT_MSG_REDIRECTION,
2.47 frystyk 114: HT_MSG_PROXY,
2.48 frystyk 115: HT_MSG_CACHE_LOCK,
2.32 frystyk 116: HT_MSG_ELEMENTS /* This MUST be the last element */
117: } HTAlertMsg;
2.45 eric 118:
119: #define HT_MSG_ENGLISH_INITIALIZER \
120: "Please enter username:", \
121: "Please enter username for proxy authentication:", \
122: "Please enter username for this FTP server:", \
123: "Password:", \
124: "Please give name of file to save in:", \
125: "Plase enter account:", \
126: "You might not be allowed to use this method here, continue?", \
127: "Location has moved, continue?", \
2.47 frystyk 128: "A new set of rules is requested to be added to your setup - continue?", \
2.45 eric 129: "This file already exists - replace existing file?", \
130: "Authentication failed - retry?", \
131: "Proxy authentication failed - retry?", \
132: "This method has already been performed - repeat operation?", \
133: "This document is very big - continue operation?", \
134: "The source document for this operation has moved - continue operation \
135: with new location?", \
136: "The destination document for this operation has moved - continue \
137: operation with new location?", \
2.47 frystyk 138: "A redirection may change the behavior of this method - proceed anyway?", \
2.48 frystyk 139: "An automatic request for changing proxy has been encountered - continue?", \
140: "The persistent cache is already in use by another user. If this is not \
141: the case then you can manually delete this lock and restart."
2.15 frystyk 142: </PRE>
2.38 frystyk 143: <H2>
144: Enable or Disable Messages
145: </H2>
146: <P>
147: If you really don't want the library to prompt for anything at all then enable
148: this constant. The default value is <EM>Interactive</EM>.
2.32 frystyk 149: <PRE>
150: extern void HTAlert_setInteractive (BOOL interative);
151: extern BOOL HTAlert_interactive (void);
2.15 frystyk 152: </PRE>
2.38 frystyk 153: <H2>
154: Creation and Deletion Methods
155: </H2>
156: <P>
157: Message methods are registered in lists. By default a list is not enabled
158: before you assign it as being <I><A HREF="#active">active</A></I>. This allows
159: the application to maintain multiple lists of message handlers which can
160: be swapped in and out as neeeded.
161: <H3>
162: Add a Callback Function
163: </H3>
164: <P>
165: Register a call back function that is to be called when generating messages,
166: dialog, prompts, progress reports etc. The opcode signifies which call back
167: function to call depending of the type of the message. Opcode can be any
168: combination of the bitflags defined by <CODE>HTAlertOpcode</CODE>. If you
169: register one callback for <CODE>HT_A_PROGRESS </CODE>then this will get called
170: on all progress notifications.
2.15 frystyk 171: <PRE>
2.32 frystyk 172: extern BOOL HTAlertCall_add (HTList * list, HTAlertCallback * cbf,
173: HTAlertOpcode opcode);
2.15 frystyk 174: </PRE>
2.38 frystyk 175: <H3>
176: Delete a Callback function
177: </H3>
178: <P>
2.32 frystyk 179: Unregister a call back function from a list
2.8 luotonen 180: <PRE>
2.32 frystyk 181: extern BOOL HTAlertCall_delete (HTList * list, HTAlertCallback * cbf);
2.15 frystyk 182: </PRE>
2.38 frystyk 183: <H3>
184: Delete a list of Callback Functions
185: </H3>
186: <P>
2.32 frystyk 187: Unregisters all call back functions
188: <PRE>
189: extern BOOL HTAlertCall_deleteAll (HTList * list);
190: </PRE>
2.38 frystyk 191: <H3>
192: Find a Callback Function
193: </H3>
194: <P>
195: Finds a callback function corresponding to the opcode. If none has been
196: registered then NULL is returned.
2.6 timbl 197: <PRE>
2.32 frystyk 198: extern HTAlertCallback * HTAlertCall_find(HTList * list, HTAlertOpcode opcode);
2.6 timbl 199: </PRE>
2.38 frystyk 200: <H2>
201: The Reply Object
202: </H2>
203: <P>
204: The reply object is used for communicating input from the <I>user</I> back
205: to the Library. This is only required to use when for example the user is
206: prompted for a file name etc. You can find several examples on how to use
207: this in the <A HREF="HTDialog.html">default message and dialog module</A>
208: provided together with the Library.
209: <PRE>extern HTAlertPar * HTAlert_newReply (void);
2.32 frystyk 210: extern void HTAlert_deleteReply (HTAlertPar * old);
211: </PRE>
2.38 frystyk 212: <H3>
213: Handle the Reply Message
214: </H3>
215: <P>
216: These methods provide the API for handling the reply message. There are two
217: ways of assigning a message to the reply message - either by copying the
218: buffer or by reusing the same buffer. In the latter case, the caller must
219: make sure <B>not</B> to free the reply message before it has been used.
2.34 frystyk 220: <PRE>
2.35 frystyk 221: extern BOOL HTAlert_setReplyMessage (HTAlertPar * me, const char *message);
2.34 frystyk 222: extern BOOL HTAlert_assignReplyMessage (HTAlertPar * me, char * message);
223: </PRE>
2.38 frystyk 224: <P>
2.34 frystyk 225: You can get the data back again by using this method:
2.32 frystyk 226: <PRE>
227: extern char * HTAlert_replyMessage (HTAlertPar * me);
2.34 frystyk 228: </PRE>
229: <PRE>
2.32 frystyk 230: extern char * HTAlert_replySecret (HTAlertPar * me);
2.35 frystyk 231: extern BOOL HTAlert_setReplySecret (HTAlertPar * me, const char * secret);
2.6 timbl 232:
2.32 frystyk 233: extern void * HTAlert_replyOutput (HTAlertPar * me);
234: extern BOOL HTAlert_setReplyOutput (HTAlertPar * me, void * output);
2.17 frystyk 235: </PRE>
2.38 frystyk 236: <H2>
237: <A NAME="active">Active set of Callback Functions</A>
238: </H2>
239: <P>
240: A list can be assigned as being active in which case it is <I>visible</I>
241: for libwww. The Library does not know about inactive lists of methods.
2.32 frystyk 242: <PRE>
243: extern void HTAlert_setGlobal (HTList * list);
244: extern HTList * HTAlert_global (void);
245: </PRE>
2.38 frystyk 246: <P>
247: You can also assign a callback directly to the global list. In this case
248: you do not need to worry about creating the list - it will be created
249: automatically.
2.17 frystyk 250: <PRE>
2.49 frystyk 251: extern BOOL HTAlert_add (HTAlertCallback * cbf, HTAlertOpcode opcode);
252: extern BOOL HTAlert_delete (HTAlertCallback * cbf);
253: extern BOOL HTAlert_deleteAll (void);
2.32 frystyk 254: extern HTAlertCallback * HTAlert_find (HTAlertOpcode opcode);
255: </PRE>
256: <PRE>
2.12 frystyk 257: #endif
258: </PRE>
2.38 frystyk 259: <P>
260: <HR>
2.37 frystyk 261: <ADDRESS>
2.50 ! frystyk 262: @(#) $Id: HTAlert.html,v 2.49 1998/05/04 19:36:11 frystyk Exp $
2.37 frystyk 263: </ADDRESS>
2.38 frystyk 264: </BODY></HTML>
Webmaster
![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to HTAlert.html CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [Public] / libwww / Library / src