Annotation of libwww/Library/src/HTAlert.html, revision 2.41
2.6 timbl 1: <HTML>
2: <HEAD>
2.38 frystyk 3: <TITLE>W3C Reference 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
40: a part of the <A HREF="http://www.w3.org/pub/WWW/Library/"> W3C Reference
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 */
66: HT_A_PROGRESS = 0xFF, /* Send a progress report - no reply */
67:
68: /* First word are reserved for progresss notifications */
69:
70: HT_A_MESSAGE = 0x1<<8, /* Send a message - no reply */
71: HT_A_CONFIRM = 0x2<<8, /* Want YES or NO back */
72: HT_A_PROMPT = 0x4<<8, /* Want full dialog */
73: HT_A_SECRET = 0x8<<8, /* Secret dialog (e.g. password) */
74: HT_A_USER_PW = 0x10<<8 /* Atomic userid and password */
75: } HTAlertOpcode;
2.15 frystyk 76:
2.32 frystyk 77: typedef struct _HTAlertPar HTAlertPar;
2.8 luotonen 78:
2.32 frystyk 79: typedef BOOL HTAlertCallback (HTRequest * request, HTAlertOpcode op,
2.35 frystyk 80: int msgnum, const char * dfault, void * input,
2.32 frystyk 81: HTAlertPar * reply);
2.6 timbl 82: </PRE>
2.38 frystyk 83: <P>
84: If you don't expect any return values then <CODE>reply</CODE> can be NULL.
85: The return value of the callback function can be used to indicate confirmation
86: on a prompt (Yes or No).
87: <H3>
88: String Messages
89: </H3>
90: <P>
91: This is an enumerated list of messages that can be converted into a string
92: table etc.
2.15 frystyk 93: <PRE>
2.32 frystyk 94: typedef enum _HTAlertMsg {
95: HT_MSG_NULL = -1,
96: HT_MSG_UID = 0,
97: HT_MSG_PW,
98: HT_MSG_FILENAME,
99: HT_MSG_ACCOUNT,
100: HT_MSG_METHOD,
101: HT_MSG_MOVED,
102: HT_MSG_RULES,
2.39 frystyk 103: HT_MSG_FILE_REPLACE,
104: HT_MSG_RETRY_AUTHENTICATION,
2.41 ! frystyk 105: HT_MSG_RETRY_PROXY_AUTH,
2.40 frystyk 106: HT_MSG_REDO,
107: HT_MSG_BIG_PUT,
108: HT_MSG_SOURCE_MOVED,
109: HT_MSG_DESTINATION_MOVED,
2.41 ! frystyk 110: HT_MSG_REDIRECTION,
2.32 frystyk 111: HT_MSG_ELEMENTS /* This MUST be the last element */
112: } HTAlertMsg;
2.15 frystyk 113: </PRE>
2.38 frystyk 114: <H2>
115: Enable or Disable Messages
116: </H2>
117: <P>
118: If you really don't want the library to prompt for anything at all then enable
119: this constant. The default value is <EM>Interactive</EM>.
2.32 frystyk 120: <PRE>
121: extern void HTAlert_setInteractive (BOOL interative);
122: extern BOOL HTAlert_interactive (void);
2.15 frystyk 123: </PRE>
2.38 frystyk 124: <H2>
125: Creation and Deletion Methods
126: </H2>
127: <P>
128: Message methods are registered in lists. By default a list is not enabled
129: before you assign it as being <I><A HREF="#active">active</A></I>. This allows
130: the application to maintain multiple lists of message handlers which can
131: be swapped in and out as neeeded.
132: <H3>
133: Add a Callback Function
134: </H3>
135: <P>
136: Register a call back function that is to be called when generating messages,
137: dialog, prompts, progress reports etc. The opcode signifies which call back
138: function to call depending of the type of the message. Opcode can be any
139: combination of the bitflags defined by <CODE>HTAlertOpcode</CODE>. If you
140: register one callback for <CODE>HT_A_PROGRESS </CODE>then this will get called
141: on all progress notifications.
2.15 frystyk 142: <PRE>
2.32 frystyk 143: extern BOOL HTAlertCall_add (HTList * list, HTAlertCallback * cbf,
144: HTAlertOpcode opcode);
2.15 frystyk 145: </PRE>
2.38 frystyk 146: <H3>
147: Delete a Callback function
148: </H3>
149: <P>
2.32 frystyk 150: Unregister a call back function from a list
2.8 luotonen 151: <PRE>
2.32 frystyk 152: extern BOOL HTAlertCall_delete (HTList * list, HTAlertCallback * cbf);
2.15 frystyk 153: </PRE>
2.38 frystyk 154: <H3>
155: Delete a list of Callback Functions
156: </H3>
157: <P>
2.32 frystyk 158: Unregisters all call back functions
159: <PRE>
160: extern BOOL HTAlertCall_deleteAll (HTList * list);
161: </PRE>
2.38 frystyk 162: <H3>
163: Find a Callback Function
164: </H3>
165: <P>
166: Finds a callback function corresponding to the opcode. If none has been
167: registered then NULL is returned.
2.6 timbl 168: <PRE>
2.32 frystyk 169: extern HTAlertCallback * HTAlertCall_find(HTList * list, HTAlertOpcode opcode);
2.6 timbl 170: </PRE>
2.38 frystyk 171: <H2>
172: The Reply Object
173: </H2>
174: <P>
175: The reply object is used for communicating input from the <I>user</I> back
176: to the Library. This is only required to use when for example the user is
177: prompted for a file name etc. You can find several examples on how to use
178: this in the <A HREF="HTDialog.html">default message and dialog module</A>
179: provided together with the Library.
180: <PRE>extern HTAlertPar * HTAlert_newReply (void);
2.32 frystyk 181: extern void HTAlert_deleteReply (HTAlertPar * old);
182: </PRE>
2.38 frystyk 183: <H3>
184: Handle the Reply Message
185: </H3>
186: <P>
187: These methods provide the API for handling the reply message. There are two
188: ways of assigning a message to the reply message - either by copying the
189: buffer or by reusing the same buffer. In the latter case, the caller must
190: make sure <B>not</B> to free the reply message before it has been used.
2.34 frystyk 191: <PRE>
2.35 frystyk 192: extern BOOL HTAlert_setReplyMessage (HTAlertPar * me, const char *message);
2.34 frystyk 193: extern BOOL HTAlert_assignReplyMessage (HTAlertPar * me, char * message);
194: </PRE>
2.38 frystyk 195: <P>
2.34 frystyk 196: You can get the data back again by using this method:
2.32 frystyk 197: <PRE>
198: extern char * HTAlert_replyMessage (HTAlertPar * me);
2.34 frystyk 199: </PRE>
200: <PRE>
2.32 frystyk 201: extern char * HTAlert_replySecret (HTAlertPar * me);
2.35 frystyk 202: extern BOOL HTAlert_setReplySecret (HTAlertPar * me, const char * secret);
2.6 timbl 203:
2.32 frystyk 204: extern void * HTAlert_replyOutput (HTAlertPar * me);
205: extern BOOL HTAlert_setReplyOutput (HTAlertPar * me, void * output);
2.17 frystyk 206: </PRE>
2.38 frystyk 207: <H2>
208: <A NAME="active">Active set of Callback Functions</A>
209: </H2>
210: <P>
211: A list can be assigned as being active in which case it is <I>visible</I>
212: for libwww. The Library does not know about inactive lists of methods.
2.32 frystyk 213: <PRE>
214: extern void HTAlert_setGlobal (HTList * list);
215: extern HTList * HTAlert_global (void);
216: </PRE>
2.38 frystyk 217: <P>
218: You can also assign a callback directly to the global list. In this case
219: you do not need to worry about creating the list - it will be created
220: automatically.
2.17 frystyk 221: <PRE>
2.33 frystyk 222: extern BOOL HTAlert_add (HTAlertCallback * cbf, HTAlertOpcode opcode);
223: extern BOOL HTAlert_delete (HTAlertCallback * cbf);
2.32 frystyk 224: extern HTAlertCallback * HTAlert_find (HTAlertOpcode opcode);
225: </PRE>
226: <PRE>
2.12 frystyk 227: #endif
228: </PRE>
2.38 frystyk 229: <P>
230: <HR>
2.37 frystyk 231: <ADDRESS>
2.41 ! frystyk 232: @(#) $Id: HTAlert.html,v 2.42 1996/07/20 00:12:33 frystyk Exp $
2.37 frystyk 233: </ADDRESS>
2.38 frystyk 234: </BODY></HTML>
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