Annotation of libwww/Library/src/HTAccess.html, revision 2.11
2.9 timbl 1: <HTML>
2: <HEAD>
2.6 timbl 3: <TITLE>HTAccess: Access manager for libwww</TITLE>
2.11 ! timbl 4: <NEXTID N="z6">
2.9 timbl 5: </HEAD>
2.5 timbl 6: <BODY>
7: <H1>Access Manager</H1>This module keeps a list of valid
8: protocol (naming scheme) specifiers
9: with associated access code. It
10: allows documents to be loaded given
11: various combinations of parameters.
12: New access protocols may be registered
13: at any time.<P>
2.9 timbl 14: Note: HTRequest defined and request
15: parametsr added to almost all calls
16: 18 Nov 1993.<P>
2.5 timbl 17: Part of the <A
2.9 timbl 18: NAME="z0" HREF="Overview.html">libwww library</A> .
2.5 timbl 19: <PRE>#ifndef HTACCESS_H
1.1 timbl 20: #define HTACCESS_H
21:
22: /* Definition uses:
23: */
24: #include "HTUtils.h"
25: #include "tcp.h"
26:
27: #ifdef SHORT_NAMES
2.8 timbl 28: #define HTClientHost HTClHost
29: #define HTSearchAbsolute HTSeAbso
30: #define HTOutputStream HTOuStre
31: #define HTOutputFormat HTOuForm
1.1 timbl 32: #endif
33:
2.10 timbl 34: </PRE>The following have to be defined
35: in advance of the other include files
36: because of circular references.
37: <PRE>typedef struct _HTRequest HTRequest;
38:
39: #include "HTAnchor.h"
40: #include <A
41: NAME="z3" HREF="HTFormat.html">"HTFormat.h"</A>
42:
43:
1.1 timbl 44: /* Return codes from load routines:
45: **
46: ** These codes may be returned by the protocol modules,
47: ** and by the HTLoad routines.
48: ** In general, positive codes are OK and negative ones are bad.
49: */
50:
51: #define HT_NO_DATA -9999 /* return code: OK but no data was loaded */
52: /* Typically, other app started or forked */
53:
2.5 timbl 54: </PRE>
2.6 timbl 55: <H2>Default Addresses</H2>These control the home page selection.
2.8 timbl 56: To mess with these for normal browses
2.6 timbl 57: is asking for user confusion.
58: <PRE>#define LOGICAL_DEFAULT "WWW_HOME" /* Defined to be the home page */
1.1 timbl 59:
2.6 timbl 60: #ifndef PERSONAL_DEFAULT
61: #define PERSONAL_DEFAULT "WWW/default.html" /* in home directory */
62: #endif
63: #ifndef LOCAL_DEFAULT_FILE
1.1 timbl 64: #define LOCAL_DEFAULT_FILE "/usr/local/lib/WWW/default.html"
2.6 timbl 65: #endif
2.7 timbl 66: /* If one telnets to a www access point,
67: it will look in this file for home page */
68: #ifndef REMOTE_POINTER
69: #define REMOTE_POINTER "/etc/www-remote.url" /* can't be file */
70: #endif
71: /* and if that fails it will use this. */
2.6 timbl 72: #ifndef REMOTE_ADDRESS
1.1 timbl 73: #define REMOTE_ADDRESS "http://info.cern.ch/remote.html" /* can't be file */
74: #endif
75:
76: /* If run from telnet daemon and no -l specified, use this file:
77: */
78: #ifndef DEFAULT_LOGFILE
79: #define DEFAULT_LOGFILE "/usr/adm/www-log/www-log"
80: #endif
81:
82: /* If the home page isn't found, use this file:
83: */
84: #ifndef LAST_RESORT
2.6 timbl 85: #define LAST_RESORT "http://info.cern.ch/default.html"
1.1 timbl 86: #endif
87:
2.10 timbl 88:
2.9 timbl 89: </PRE>
90: <H2><A
91: NAME="z1">The Request structure</A></H2>When a request is handled, all kinds
92: of things about it need to be passed
93: along. These are all put into a
2.11 ! timbl 94: HTRequest structure. Note there
! 95: is also a <A
! 96: NAME="z4" HREF="HTFormat.html#z17">global list of converters</A>.
2.10 timbl 97: <PRE>struct _HTRequest {
2.11 ! timbl 98: HTList * <A
! 99: NAME="z5">conversions</A>; /* conversions allowed in this case */
2.9 timbl 100: char * from; /* On behalf of whom? */
101: HTStream* output_stream; /* For non-interactive, set this */
2.10 timbl 102: HTAtom * output_format; /* To convert on load, set this */
2.9 timbl 103: BOOL (*callback) PARAMS((
104: struct _HTRequest* request,
105: void *param));
106: void * context; /* caller data -- HTAccess unaware */
107:
108: HTParentAnchor* anchor; /* Set by HTAccess */
109: /* To be added: authentication, etc */
2.10 timbl 110: };
2.9 timbl 111:
112: </PRE>The elements of the request structure
113: are as follows.
114: <DL>
115: <DT>conversions
2.10 timbl 116: <DD> NULL, or a list of conversions
2.9 timbl 117: which the format manager can do in
118: order to fulfill the request. This
119: is set by the caller of HTAccess.
2.10 timbl 120: Typically points to a list set up
2.9 timbl 121: an initialisation time for example
122: by HTInit.
123: <DT>from
2.10 timbl 124: <DD> Email format adderss of person
2.9 timbl 125: responible for request
126: <DT>output_stream
2.10 timbl 127: <DD> NULL or if a specific
2.9 timbl 128: output stream is required, te stream.
129: <DT>output_format
2.10 timbl 130: <DD> The output format required,
2.9 timbl 131: or a generic format such as www/present
132: (present to user).
133: <DT>anchor
2.10 timbl 134: <DD> The anchor for teh object
135: in question. NOTE: Set by HTAcesss.
2.9 timbl 136: </DL>
137: Just to make things easier especially
138: for clients, here is a function to
139: return a new blank request:
140: <H2>Create blank request</H2>This request has defaults in -- in
141: most cases it will need some information
142: added before being passed to HTAccess,
143: but it will work as is for a simple
144: request.
145: <PRE>extern HTRequest * HTRequest_new NOPARAMS;
1.1 timbl 146:
2.9 timbl 147:
2.5 timbl 148: </PRE>
149: <H2>Flags which may be set to control
150: this module</H2>
151: <PRE>extern int HTDiag; /* Flag: load source as plain text */
1.1 timbl 152: extern char * HTClientHost; /* Name or number of telnetting host */
153: extern FILE * logfile; /* File to output one-liners to */
2.7 timbl 154: extern BOOL HTSecure; /* Disable security holes? */
1.1 timbl 155:
156:
157:
2.5 timbl 158: </PRE>
159: <H2>Load a document from relative name</H2>
160: <H3>On Entry,</H3>
161: <DL>
162: <DT>relative_name
2.6 timbl 163: <DD> The relative address
2.5 timbl 164: of the file to be accessed.
165: <DT>here
2.6 timbl 166: <DD> The anchor of the object being
2.5 timbl 167: searched
2.9 timbl 168: <DT>request->anchor
169: <DD> not filled in yet
2.5 timbl 170: </DL>
171:
172: <H3>On Exit,</H3>
173: <DL>
174: <DT>returns YES
2.6 timbl 175: <DD> Success in opening
2.5 timbl 176: file
177: <DT>NO
2.6 timbl 178: <DD> Failure
2.5 timbl 179: </DL>
1.1 timbl 180:
2.5 timbl 181: <PRE>extern BOOL HTLoadRelative PARAMS((
1.1 timbl 182: CONST char * relative_name,
2.9 timbl 183: HTParentAnchor * here,
184: HTRequest * request));
1.1 timbl 185:
186:
2.5 timbl 187: </PRE>
188: <H2>Load a document from absolute name</H2>
189: <H3>On Entry,</H3>
190: <DL>
191: <DT>addr
2.6 timbl 192: <DD> The absolute address of the
193: document to be accessed.
2.5 timbl 194: <DT>filter
2.6 timbl 195: <DD> if YES, treat document as
196: HTML
2.9 timbl 197: <DT>request->anchor
198: <DD> not filled in yet
2.5 timbl 199: </DL>
1.1 timbl 200:
2.5 timbl 201: <PRE>
202: </PRE>
203: <H3>On Exit,</H3>
204: <PRE>
205: </PRE>
206: <DL>
207: <DT>returns YES
2.6 timbl 208: <DD> Success in opening document
2.5 timbl 209: <DT>NO
2.6 timbl 210: <DD> Failure
2.5 timbl 211: </DL>
1.1 timbl 212:
2.9 timbl 213: <PRE>extern BOOL HTLoadAbsolute PARAMS((CONST char * addr,
214: HTRequest * request));
1.1 timbl 215:
216:
2.5 timbl 217: </PRE>
218: <H2>Load a document from absolute name
219: to a stream</H2>
220: <H3>On Entry,</H3>
221: <DL>
222: <DT>addr
2.6 timbl 223: <DD> The absolute address of the
224: document to be accessed.
2.5 timbl 225: <DT>filter
2.6 timbl 226: <DD> if YES, treat document as
227: HTML
2.9 timbl 228: <DT>request->anchor
229: <DD> not filled in yet
2.5 timbl 230: </DL>
231:
232: <H3>On Exit,</H3>
233: <DL>
234: <DT>returns YES
2.6 timbl 235: <DD> Success in opening document
2.5 timbl 236: <DT>NO
2.6 timbl 237: <DD> Failure
2.5 timbl 238: </DL>
239: Note: This is equivalent to HTLoadDocument
2.9 timbl 240: <PRE>extern BOOL HTLoadToStream PARAMS((
241: CONST char * addr,
242: BOOL filter,
243: HTRequest * request));
1.1 timbl 244:
245:
2.5 timbl 246: </PRE>
247: <H2>Load if necessary, and select an
2.9 timbl 248: anchor</H2>The anchor parameter may be a child
249: anchor. The anchor in the request
250: is set to the parent anchor.
2.5 timbl 251: <H3>On Entry,</H3>
252: <DL>
2.9 timbl 253: <DT>anchor
254: <DD> may be a child or parenet
255: anchor or 0 in which case there is
256: no effect.
257: <DT>request->anchor
258: <DD> Not set
259: yet.
2.5 timbl 260: </DL>
261:
262: <H3>On Exit,</H3>
263: <PRE>
264: </PRE>
265: <DL>
266: <DT>returns YES
2.6 timbl 267: <DD> Success
2.5 timbl 268: <DT>returns NO
2.6 timbl 269: <DD> Failure
2.9 timbl 270: <DT>request->anchor
271: <DD> The parenet anchor.
2.5 timbl 272: </DL>
273:
2.9 timbl 274: <PRE>extern BOOL HTLoadAnchor PARAMS((HTAnchor * a,
275: HTRequest * request));
1.1 timbl 276:
277:
2.5 timbl 278: </PRE>
279: <H2>Make a stream for Saving object back</H2>
280: <H3>On Entry,</H3>
281: <DL>
2.9 timbl 282: <DT>request->anchor
283: <DD> is valid anchor which
284: has previously beeing loaded
2.5 timbl 285: </DL>
286:
287: <H3>On exit,</H3>
288: <DL>
289: <DT>returns
2.6 timbl 290: <DD> 0 if error else a stream
291: to save the object to.
2.5 timbl 292: </DL>
293:
294: <PRE>
295:
2.9 timbl 296: extern HTStream * HTSaveStream PARAMS((HTParentAnchor* anchor,
297: HTRequest * request));
1.1 timbl 298:
299:
2.5 timbl 300: </PRE>
301: <H2>Search</H2>Performs a search on word given by
302: the user. Adds the search words to
303: the end of the current address and
304: attempts to open the new address.
305: <H3>On Entry,</H3>
306: <DL>
307: <DT>*keywords
2.6 timbl 308: <DD> space-separated keyword
2.5 timbl 309: list or similar search list
310: <DT>here
2.6 timbl 311: <DD> The anchor of the object being
2.5 timbl 312: searched
313: </DL>
1.1 timbl 314:
2.9 timbl 315: <PRE>extern BOOL HTSearch PARAMS((
316: CONST char * keywords,
317: HTParentAnchor* here,
318: HTRequest * request));
1.1 timbl 319:
320:
2.5 timbl 321: </PRE>
322: <H2>Search Given Indexname</H2>Performs a keyword search on word
323: given by the user. Adds the keyword
324: to the end of the current address
325: and attempts to open the new address.
326: <H3>On Entry,</H3>
327: <DL>
328: <DT>*keywords
2.6 timbl 329: <DD> space-separated keyword
2.5 timbl 330: list or similar search list
331: <DT>*indexname
2.6 timbl 332: <DD> is name of object search
2.5 timbl 333: is to be done on.
334: </DL>
1.1 timbl 335:
2.5 timbl 336: <PRE>extern BOOL HTSearchAbsolute PARAMS((
2.9 timbl 337: CONST char * keywords,
338: CONST char * indexname,
339: HTRequest * request));
1.1 timbl 340:
341:
2.5 timbl 342: </PRE>
2.9 timbl 343: <H2>Register an access method</H2>An access method is defined by an
344: HTProtocol structure which point
345: to the routines for performing the
346: various logical operations on an
347: object: in HTTP terms, GET, PUT,
348: and POST.<P>
349: Each of these routine takes as a
350: parameter a <A
351: NAME="z2" HREF="#z1">request structure</A> containing
352: details ofthe request. When the
353: protocol class routine is called,
354: the anchor elemnt in the request
355: is already valid (made valid by HTAccess).
356: <PRE>typedef struct _HTProtocol {
1.1 timbl 357: char * name;
358:
2.11 ! timbl 359: int (*load)PARAMS((HTRequest * request));
1.1 timbl 360:
2.11 ! timbl 361: HTStream* (*saveStream)PARAMS((HTRequest * request));
! 362:
2.9 timbl 363: HTStream* (*postStream)PARAMS((
364: HTRequest * request,
365: HTParentAnchor* postTo));
1.1 timbl 366:
367: } HTProtocol;
368:
369: extern BOOL HTRegisterProtocol PARAMS((HTProtocol * protocol));
370:
371:
2.5 timbl 372: </PRE>
373: <H2>Generate the anchor for the home
374: page</H2>
375: <PRE>
376: </PRE>As it involves file access, this
377: should only be done once when the
378: program first runs. This is a default
379: algorithm -- browser don't HAVE to
380: use this.
381: <PRE>extern HTParentAnchor * HTHomeAnchor NOPARAMS;
1.1 timbl 382:
383: #endif /* HTACCESS_H */
2.11 ! timbl 384:
! 385: </PRE>end of HTAccess</A></BODY>
2.9 timbl 386: </HTML>
Webmaster
![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to HTAccess.html CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [Public] / libwww / Library / src