Annotation of libwww/Library/src/HTError.html, revision 2.50
2.1 frystyk 1: <HTML>
2: <HEAD>
2.40 frystyk 3: <!-- Changed by: Henrik Frystyk Nielsen, 4-Jul-1996 -->
2.43 frystyk 4: <TITLE>W3C Sample Code Library libwww Error Class</TITLE>
2.1 frystyk 5: </HEAD>
6: <BODY>
2.37 frystyk 7: <H1>
8: The Error Class
9: </H1>
2.18 frystyk 10: <PRE>
11: /*
2.22 frystyk 12: ** (c) COPYRIGHT MIT 1995.
2.18 frystyk 13: ** Please first read the full copyright statement in the file COPYRIGH.
14: */
15: </PRE>
2.37 frystyk 16: <P>
17: The Error class provides an easy API for registering errors ocurring while
2.49 frystyk 18: libwww serves a request. All errors are registered in an "error stack" in
19: the <A HREF="HTReq.html">Request object</A> which allows for nested errors.
20: The Error class is both natural language independent and application independent
21: in that it uses enumerations in order to refer to specific errors. It is
22: for the application to provide an error presentation module which interprets
23: the errors associated with a request. An eample of such an implementation
24: can be found in the <A HREF="HTDialog.html">HTDialog module</A>.
2.37 frystyk 25: <P>
26: This module is implemented by <A HREF="HTError.c">HTError.c</A>, and it is
2.47 frystyk 27: a part of the <A HREF="http://www.w3.org/Library/"> W3C Sample Code
2.37 frystyk 28: Library</A>.
2.1 frystyk 29: <PRE>
30: #ifndef HTERROR_H
31: #define HTERROR_H
2.36 frystyk 32:
33: typedef struct _HTError HTError;
34:
35: typedef enum _HTSeverity {
36: ERR_UNKNOWN = 0x0,
37: ERR_FATAL = 0x1,
38: ERR_NON_FATAL = 0x2,
39: ERR_WARN = 0x4,
40: ERR_INFO = 0x8
41: } HTSeverity;
42:
2.28 frystyk 43: #include "HTReq.h"
2.1 frystyk 44: </PRE>
2.37 frystyk 45: <H2>
2.50 ! frystyk 46: <A NAME="errorinfo">The Error Message Object</A>
2.37 frystyk 47: </H2>
48: <P>
2.49 frystyk 49: An error consists of a messsage code, a short, natural language specific
50: message, and a URI which can point to more information. This module also
51: provides a <A HREF="#Lang">default set of error objects with English text</A>.
52: Errors are registered together with a severity and you can also set the mode
53: for <A HREF="#What">what class of error severities should be shown and which
54: should be ignored</A>.
55: <PRE>
56: typedef struct _HTErrorMessage {
57: int code; /* Error number */
58: char * msg; /* Short explanation */
59: char * url; /* Explaning URL */
60: } HTErrorMessage;
61: </PRE>
62: <H3>
63: <A NAME="Codes">Error Message Index</A>
64: </H3>
65: <P>
2.50 ! frystyk 66: <B>Note:</B> All non-HTTP error codes have (<CODE>index number >
! 67: HTERR_HTTP_CODES</CODE>), and they will not be shown in the error-message
! 68: generated.
! 69: <P>
2.49 frystyk 70: Error codes are registered in an array where the following enumerations serve
2.50 ! frystyk 71: as an index. They must <STRONG>not</STRONG> be replaced! See the
! 72: <A HREF="HTDialog.html#Messsages">HTDialog module</A> for default initialization
! 73: of these messages.
2.1 frystyk 74: <PRE>
75: typedef enum _HTErrorElement {
2.38 frystyk 76: HTERR_CONTINUE = 0, /* 100 */
77: HTERR_SWITCHING, /* 101 */
78: HTERR_OK, /* 200 */
2.1 frystyk 79: HTERR_CREATED, /* 201 */
80: HTERR_ACCEPTED, /* 202 */
2.38 frystyk 81: HTERR_NON_AUTHORITATIVE, /* 203 */
2.23 frystyk 82: HTERR_NO_CONTENT, /* 204 */
2.38 frystyk 83: HTERR_RESET, /* 205 */
84: HTERR_PARTIAL, /* 206 */
2.45 frystyk 85: HTERR_PARTIAL_OK, /* 207 */
2.38 frystyk 86: HTERR_MULTIPLE, /* 300 */
2.1 frystyk 87: HTERR_MOVED, /* 301 */
88: HTERR_FOUND, /* 302 */
89: HTERR_METHOD, /* 303 */
90: HTERR_NOT_MODIFIED, /* 304 */
2.38 frystyk 91: HTERR_USE_PROXY, /* 305 */
2.45 frystyk 92: HTERR_PROXY_REDIRECT, /* 306 */
93: HTERR_TEMP_REDIRECT, /* 307 */
2.1 frystyk 94: HTERR_BAD_REQUEST, /* 400 */
95: HTERR_UNAUTHORIZED, /* 401 */
96: HTERR_PAYMENT_REQUIRED, /* 402 */
97: HTERR_FORBIDDEN, /* 403 */
98: HTERR_NOT_FOUND, /* 404 */
2.20 frystyk 99: HTERR_NOT_ALLOWED, /* 405 */
100: HTERR_NONE_ACCEPTABLE, /* 406 */
2.38 frystyk 101: HTERR_PROXY_UNAUTHORIZED, /* 407 */
2.20 frystyk 102: HTERR_TIMEOUT, /* 408 */
2.38 frystyk 103: HTERR_CONFLICT, /* 409 */
104: HTERR_GONE, /* 410 */
105: HTERR_LENGTH_REQUIRED, /* 411 */
106: HTERR_PRECON_FAILED, /* 412 */
107: HTERR_TOO_BIG, /* 413 */
108: HTERR_URI_TOO_BIG, /* 414 */
109: HTERR_UNSUPPORTED, /* 415 */
2.45 frystyk 110: HTERR_BAD_RANGE, /* 416 */
111: HTERR_EXPECTATION_FAILED, /* 417 */
112: HTERR_REAUTH, /* 418 */
113: HTERR_PROXY_REAUTH, /* 419 */
2.1 frystyk 114: HTERR_INTERNAL, /* 500 */
115: HTERR_NOT_IMPLEMENTED, /* 501 */
2.20 frystyk 116: HTERR_BAD_GATE, /* 502 */
117: HTERR_DOWN, /* 503 */
118: HTERR_GATE_TIMEOUT, /* 504 */
2.38 frystyk 119: HTERR_BAD_VERSION, /* 505 */
2.45 frystyk 120: HTERR_NO_PARTIAL_UPDATE, /* 506 */
2.38 frystyk 121:
122: /* Cache warnings */
123: HTERR_STALE, /* 10 */
124: HTERR_REVALIDATION_FAILED, /* 11 */
125: HTERR_DISCONNECTED_CACHE, /* 12 */
126: HTERR_HEURISTIC_EXPIRATION, /* 13 */
127: HTERR_TRANSFORMED, /* 14 */
128: HTERR_CACHE, /* 99 */
129:
130: /* Put all non-HTTP status codes after this */
2.1 frystyk 131: HTERR_NO_REMOTE_HOST,
2.13 frystyk 132: HTERR_NO_HOST,
2.31 frystyk 133: HTERR_NO_FILE,
2.1 frystyk 134: HTERR_FTP_SERVER,
135: HTERR_FTP_NO_RESPONSE,
2.46 frystyk 136: HTERR_FTP_LOGIN_FAILURE,
2.1 frystyk 137: HTERR_TIME_OUT,
2.2 frystyk 138: HTERR_GOPHER_SERVER,
139: HTERR_INTERRUPTED,
2.13 frystyk 140: HTERR_CON_INTR,
2.2 frystyk 141: HTERR_CSO_SERVER,
2.20 frystyk 142: HTERR_HTTP09,
143: HTERR_BAD_REPLY,
2.16 frystyk 144: HTERR_UNKNOWN_AA,
2.5 frystyk 145: HTERR_NEWS_SERVER,
2.7 frystyk 146: HTERR_FILE_TO_FTP,
2.39 frystyk 147: HTERR_AUTO_REDIRECT,
2.8 frystyk 148: HTERR_MAX_REDIRECT,
2.16 frystyk 149: HTERR_EOF,
2.14 frystyk 150: HTERR_WAIS_OVERFLOW,
151: HTERR_WAIS_MODULE,
2.12 frystyk 152: HTERR_WAIS_NO_CONNECT,
2.2 frystyk 153: HTERR_SYSTEM,
2.29 frystyk 154: HTERR_CLASS,
2.31 frystyk 155: HTERR_ACCESS,
156: HTERR_LOGIN,
2.41 frystyk 157: HTERR_CACHE_EXPIRED,
2.44 frystyk 158: HTERR_NO_AUTO_RULES,
159: HTERR_NO_AUTO_PROXY,
2.1 frystyk 160: HTERR_ELEMENTS /* This MUST be the last element */
161: } HTErrorElement;
2.30 frystyk 162: </PRE>
2.49 frystyk 163: <H3>
164: <A NAME="Lang">Default English Language Messages</A>
165: </H3>
2.37 frystyk 166: <P>
2.49 frystyk 167: Default set of error messages arranged in an array into which the
2.50 ! frystyk 168: <A HREF="#Codes">index codes</A> serve as index. See the
! 169: <A HREF="HTDialog.html#Messsages">HTDialog module</A> for default initialization
! 170: of these strings.
2.49 frystyk 171: <H2>
172: <A NAME="What">What Errors should be Ignored or Passed Through?</A>
173: </H2>
174: <P>
175: This variable dictates which errors should be put out when generating the
176: message to the user. The first four enumerations make it possible to see
177: `everything as bad or worse than' this level, e.g. <CODE>HT_ERR_SHOW_NON_FATAL
178: </CODE>shows messages of type <CODE>HT_ERR_SHOW_NON_FATAL </CODE>and
179: <CODE>HT_ERR_SHOW_FATAL</CODE>.
180: <P>
181: <B>Note:</B> The default value is made so that it only puts a message to
182: <EM>stderr</EM> if a `real' error has occurred. If a separate widget is available
183: for information and error messages then probably
184: <CODE>HT_ERR_SHOW_DETAILED</CODE> would be more appropriate.
185: <PRE>
186: typedef enum _HTErrorShow {
187: HT_ERR_SHOW_FATAL = 0x1,
188: HT_ERR_SHOW_NON_FATAL = 0x3,
189: HT_ERR_SHOW_WARNING = 0x7,
190: HT_ERR_SHOW_INFO = 0xF,
191: HT_ERR_SHOW_PARS = 0x10,
192: HT_ERR_SHOW_LOCATION = 0x20,
193: HT_ERR_SHOW_IGNORE = 0x40,
194: HT_ERR_SHOW_FIRST = 0x80,
195: HT_ERR_SHOW_LINKS = 0x100,
196: HT_ERR_SHOW_DEFAULT = 0x13,
197: HT_ERR_SHOW_DETAILED = 0x1F,
198: HT_ERR_SHOW_DEBUG = 0x7F
199: } HTErrorShow;
2.44 frystyk 200:
2.37 frystyk 201: extern HTErrorShow HTError_show (void);
202: extern BOOL HTError_setShow (HTErrorShow mask);
203: </PRE>
204: <H2>
205: Creation and Deletion Methods
206: </H2>
207: <H3>
208: Add an Error
209: </H3>
210: <P>
211: Add an error message to the error list. `par' and `where' might be set to
212: NULL. If par is a string, it is sufficient to let length be unspecified,
213: i.e., 0. If only a part of the string is wanted then specify a length inferior
214: to strlen((char *) par). The string is '\0' terminated automaticly. See also
215: HTError_addSystem for system errors. Returns YES if OK, else NO.
2.30 frystyk 216: <PRE>
217: extern BOOL HTError_add (HTList * list,
218: HTSeverity severity,
219: BOOL ignore,
220: int element,
221: void * par,
222: unsigned int length,
223: char * where);
224:
225: </PRE>
2.37 frystyk 226: <H3>
227: Add a System Error
228: </H3>
229: <P>
230: Add a system error message to the error list. syscall is the name of the
231: system call, e.g. "close". The message put to the list is that corresponds
232: to the error number passed. See also HTError_add. Returns YES if OK, else
233: NO.
2.30 frystyk 234: <PRE>
235: extern BOOL HTError_addSystem (HTList * list,
236: HTSeverity severity,
237: int errornumber,
238: BOOL ignore,
239: char * syscall);
240: </PRE>
2.37 frystyk 241: <H3>
242: Delete an Entire Error Stack
243: </H3>
244: <P>
2.30 frystyk 245: Deletes all errors in a list.
246: <PRE>
247: extern BOOL HTError_deleteAll (HTList * list);
2.1 frystyk 248: </PRE>
2.37 frystyk 249: <H3>
250: Deletes the Last Edded Entry
251: </H3>
252: <P>
2.30 frystyk 253: Deletes the last error entry added to the list. Return YES if OK, else NO
254: <PRE>
255: extern BOOL HTError_deleteLast (HTList * list);
256: </PRE>
2.37 frystyk 257: <H2>
2.40 frystyk 258: Object Methods
2.37 frystyk 259: </H2>
260: <H3>
261: Show the Error Entry?
262: </H3>
263: <P>
2.30 frystyk 264: Should we show this entry in the list or just continue to the next one?
2.1 frystyk 265: <PRE>
2.30 frystyk 266: extern BOOL HTError_doShow (HTError * info);
2.1 frystyk 267: </PRE>
2.37 frystyk 268: <H3>
269: Ignore last Added Error
270: </H3>
271: <P>
272: Turns on the `ignore' flag for the most recent error entered the error list.
273: Returns YES if OK else NO
2.1 frystyk 274: <PRE>
2.30 frystyk 275: extern BOOL HTError_ignoreLast (HTList * list);
276: extern BOOL HTError_setIgnore (HTError * info);
2.2 frystyk 277: </PRE>
2.37 frystyk 278: <H3>
279: Error Index Number
280: </H3>
281: <P>
282: Each error object is assigned an index number as defined by the
283: <CODE>HTErrorElement</CODE> above. The mapping from this index to an error
284: code and a message must be done by the application. The Library provides
285: a default implementation in the <A HREF="HTDialog.html"> HTDialog module</A>,
286: but that can of course be changed depending on the application.
2.15 frystyk 287: <PRE>
2.31 frystyk 288: extern int HTError_index (HTError * info);
2.37 frystyk 289: </PRE>
290: <H3>
291: Error Severity
292: </H3>
2.40 frystyk 293: <P>
294: This function returns the severity of the error object passed by the caller
295: <PRE>extern HTSeverity HTError_severity (HTError * info);
296: </PRE>
297: <P>
298: You can ask whether a list of errors contains any error object with a severity
299: level which is higher than the one specifed.
300: <PRE>extern BOOL HTError_hasSeverity (HTList * list, HTSeverity severity);
2.37 frystyk 301: </PRE>
302: <H3>
303: Parameters Asscotiated with Error
304: </H3>
305: <PRE>
2.30 frystyk 306: extern void * HTError_parameter (HTError * info, int * length);
2.37 frystyk 307: </PRE>
308: <H3>
309: Where did it happen?
310: </H3>
311: <PRE>
2.34 frystyk 312: extern const char * HTError_location (HTError * info);
2.1 frystyk 313: </PRE>
314: <PRE>
2.50 ! frystyk 315: #endif /* HTERROR_H */
2.1 frystyk 316: </PRE>
2.37 frystyk 317: <P>
318: <HR>
2.36 frystyk 319: <ADDRESS>
2.50 ! frystyk 320: @(#) $Id: HTError.html,v 2.49 1998/10/26 21:36:25 frystyk Exp $
2.36 frystyk 321: </ADDRESS>
2.37 frystyk 322: </BODY></HTML>
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