Annotation of libwww/Library/src/HTAccess.html, revision 2.12
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
2.12 ! timbl 96: NAME="z4" HREF="HTFormat.html#z17">global list of converters</A>
! 97: .
2.10 timbl 98: <PRE>struct _HTRequest {
2.11 timbl 99: HTList * <A
2.12 ! timbl 100: NAME="z5">conversions</A> ; /* conversions allowed in this case */
2.9 timbl 101: char * from; /* On behalf of whom? */
102: HTStream* output_stream; /* For non-interactive, set this */
2.10 timbl 103: HTAtom * output_format; /* To convert on load, set this */
2.9 timbl 104: BOOL (*callback) PARAMS((
105: struct _HTRequest* request,
106: void *param));
107: void * context; /* caller data -- HTAccess unaware */
108:
109: HTParentAnchor* anchor; /* Set by HTAccess */
2.12 ! timbl 110:
! 111: void * using_cache; /* pointer to cache element if cache hit */
! 112:
2.9 timbl 113: /* To be added: authentication, etc */
2.10 timbl 114: };
2.9 timbl 115:
116: </PRE>The elements of the request structure
117: are as follows.
118: <DL>
119: <DT>conversions
2.10 timbl 120: <DD> NULL, or a list of conversions
2.9 timbl 121: which the format manager can do in
122: order to fulfill the request. This
123: is set by the caller of HTAccess.
2.10 timbl 124: Typically points to a list set up
2.9 timbl 125: an initialisation time for example
126: by HTInit.
127: <DT>from
2.10 timbl 128: <DD> Email format adderss of person
2.9 timbl 129: responible for request
130: <DT>output_stream
2.10 timbl 131: <DD> NULL or if a specific
2.9 timbl 132: output stream is required, te stream.
133: <DT>output_format
2.10 timbl 134: <DD> The output format required,
2.9 timbl 135: or a generic format such as www/present
136: (present to user).
137: <DT>anchor
2.10 timbl 138: <DD> The anchor for teh object
139: in question. NOTE: Set by HTAcesss.
2.9 timbl 140: </DL>
141: Just to make things easier especially
142: for clients, here is a function to
143: return a new blank request:
144: <H2>Create blank request</H2>This request has defaults in -- in
145: most cases it will need some information
146: added before being passed to HTAccess,
147: but it will work as is for a simple
148: request.
149: <PRE>extern HTRequest * HTRequest_new NOPARAMS;
1.1 timbl 150:
2.9 timbl 151:
2.5 timbl 152: </PRE>
153: <H2>Flags which may be set to control
154: this module</H2>
155: <PRE>extern int HTDiag; /* Flag: load source as plain text */
1.1 timbl 156: extern char * HTClientHost; /* Name or number of telnetting host */
157: extern FILE * logfile; /* File to output one-liners to */
2.7 timbl 158: extern BOOL HTSecure; /* Disable security holes? */
1.1 timbl 159:
160:
161:
2.5 timbl 162: </PRE>
163: <H2>Load a document from relative name</H2>
164: <H3>On Entry,</H3>
165: <DL>
166: <DT>relative_name
2.6 timbl 167: <DD> The relative address
2.5 timbl 168: of the file to be accessed.
169: <DT>here
2.6 timbl 170: <DD> The anchor of the object being
2.5 timbl 171: searched
2.9 timbl 172: <DT>request->anchor
173: <DD> not filled in yet
2.5 timbl 174: </DL>
175:
176: <H3>On Exit,</H3>
177: <DL>
178: <DT>returns YES
2.6 timbl 179: <DD> Success in opening
2.5 timbl 180: file
181: <DT>NO
2.6 timbl 182: <DD> Failure
2.5 timbl 183: </DL>
1.1 timbl 184:
2.5 timbl 185: <PRE>extern BOOL HTLoadRelative PARAMS((
1.1 timbl 186: CONST char * relative_name,
2.9 timbl 187: HTParentAnchor * here,
188: HTRequest * request));
1.1 timbl 189:
190:
2.5 timbl 191: </PRE>
192: <H2>Load a document from absolute name</H2>
193: <H3>On Entry,</H3>
194: <DL>
195: <DT>addr
2.6 timbl 196: <DD> The absolute address of the
197: document to be accessed.
2.5 timbl 198: <DT>filter
2.6 timbl 199: <DD> if YES, treat document as
200: HTML
2.9 timbl 201: <DT>request->anchor
202: <DD> not filled in yet
2.5 timbl 203: </DL>
1.1 timbl 204:
2.5 timbl 205: <PRE>
206: </PRE>
207: <H3>On Exit,</H3>
208: <PRE>
209: </PRE>
210: <DL>
211: <DT>returns YES
2.6 timbl 212: <DD> Success in opening document
2.5 timbl 213: <DT>NO
2.6 timbl 214: <DD> Failure
2.5 timbl 215: </DL>
1.1 timbl 216:
2.9 timbl 217: <PRE>extern BOOL HTLoadAbsolute PARAMS((CONST char * addr,
218: HTRequest * request));
1.1 timbl 219:
220:
2.5 timbl 221: </PRE>
222: <H2>Load a document from absolute name
223: to a stream</H2>
224: <H3>On Entry,</H3>
225: <DL>
226: <DT>addr
2.6 timbl 227: <DD> The absolute address of the
228: document to be accessed.
2.5 timbl 229: <DT>filter
2.6 timbl 230: <DD> if YES, treat document as
231: HTML
2.9 timbl 232: <DT>request->anchor
233: <DD> not filled in yet
2.5 timbl 234: </DL>
235:
236: <H3>On Exit,</H3>
237: <DL>
238: <DT>returns YES
2.6 timbl 239: <DD> Success in opening document
2.5 timbl 240: <DT>NO
2.6 timbl 241: <DD> Failure
2.5 timbl 242: </DL>
243: Note: This is equivalent to HTLoadDocument
2.9 timbl 244: <PRE>extern BOOL HTLoadToStream PARAMS((
245: CONST char * addr,
246: BOOL filter,
247: HTRequest * request));
1.1 timbl 248:
249:
2.5 timbl 250: </PRE>
251: <H2>Load if necessary, and select an
2.9 timbl 252: anchor</H2>The anchor parameter may be a child
253: anchor. The anchor in the request
254: is set to the parent anchor.
2.5 timbl 255: <H3>On Entry,</H3>
256: <DL>
2.9 timbl 257: <DT>anchor
258: <DD> may be a child or parenet
259: anchor or 0 in which case there is
260: no effect.
261: <DT>request->anchor
262: <DD> Not set
263: yet.
2.5 timbl 264: </DL>
265:
266: <H3>On Exit,</H3>
267: <PRE>
268: </PRE>
269: <DL>
270: <DT>returns YES
2.6 timbl 271: <DD> Success
2.5 timbl 272: <DT>returns NO
2.6 timbl 273: <DD> Failure
2.9 timbl 274: <DT>request->anchor
275: <DD> The parenet anchor.
2.5 timbl 276: </DL>
277:
2.9 timbl 278: <PRE>extern BOOL HTLoadAnchor PARAMS((HTAnchor * a,
279: HTRequest * request));
1.1 timbl 280:
281:
2.5 timbl 282: </PRE>
283: <H2>Make a stream for Saving object back</H2>
284: <H3>On Entry,</H3>
285: <DL>
2.9 timbl 286: <DT>request->anchor
287: <DD> is valid anchor which
288: has previously beeing loaded
2.5 timbl 289: </DL>
290:
291: <H3>On exit,</H3>
292: <DL>
293: <DT>returns
2.6 timbl 294: <DD> 0 if error else a stream
295: to save the object to.
2.5 timbl 296: </DL>
297:
298: <PRE>
299:
2.9 timbl 300: extern HTStream * HTSaveStream PARAMS((HTParentAnchor* anchor,
301: HTRequest * request));
1.1 timbl 302:
303:
2.5 timbl 304: </PRE>
305: <H2>Search</H2>Performs a search on word given by
306: the user. Adds the search words to
307: the end of the current address and
308: attempts to open the new address.
309: <H3>On Entry,</H3>
310: <DL>
311: <DT>*keywords
2.6 timbl 312: <DD> space-separated keyword
2.5 timbl 313: list or similar search list
314: <DT>here
2.6 timbl 315: <DD> The anchor of the object being
2.5 timbl 316: searched
317: </DL>
1.1 timbl 318:
2.9 timbl 319: <PRE>extern BOOL HTSearch PARAMS((
320: CONST char * keywords,
321: HTParentAnchor* here,
322: HTRequest * request));
1.1 timbl 323:
324:
2.5 timbl 325: </PRE>
326: <H2>Search Given Indexname</H2>Performs a keyword search on word
327: given by the user. Adds the keyword
328: to the end of the current address
329: and attempts to open the new address.
330: <H3>On Entry,</H3>
331: <DL>
332: <DT>*keywords
2.6 timbl 333: <DD> space-separated keyword
2.5 timbl 334: list or similar search list
335: <DT>*indexname
2.6 timbl 336: <DD> is name of object search
2.5 timbl 337: is to be done on.
338: </DL>
1.1 timbl 339:
2.5 timbl 340: <PRE>extern BOOL HTSearchAbsolute PARAMS((
2.9 timbl 341: CONST char * keywords,
342: CONST char * indexname,
343: HTRequest * request));
1.1 timbl 344:
345:
2.5 timbl 346: </PRE>
2.9 timbl 347: <H2>Register an access method</H2>An access method is defined by an
348: HTProtocol structure which point
349: to the routines for performing the
350: various logical operations on an
351: object: in HTTP terms, GET, PUT,
352: and POST.<P>
353: Each of these routine takes as a
354: parameter a <A
355: NAME="z2" HREF="#z1">request structure</A> containing
356: details ofthe request. When the
357: protocol class routine is called,
358: the anchor elemnt in the request
359: is already valid (made valid by HTAccess).
360: <PRE>typedef struct _HTProtocol {
1.1 timbl 361: char * name;
362:
2.11 timbl 363: int (*load)PARAMS((HTRequest * request));
1.1 timbl 364:
2.11 timbl 365: HTStream* (*saveStream)PARAMS((HTRequest * request));
366:
2.9 timbl 367: HTStream* (*postStream)PARAMS((
368: HTRequest * request,
369: HTParentAnchor* postTo));
1.1 timbl 370:
371: } HTProtocol;
372:
373: extern BOOL HTRegisterProtocol PARAMS((HTProtocol * protocol));
374:
375:
2.5 timbl 376: </PRE>
377: <H2>Generate the anchor for the home
378: page</H2>
379: <PRE>
380: </PRE>As it involves file access, this
381: should only be done once when the
382: program first runs. This is a default
383: algorithm -- browser don't HAVE to
384: use this.
385: <PRE>extern HTParentAnchor * HTHomeAnchor NOPARAMS;
1.1 timbl 386:
387: #endif /* HTACCESS_H */
2.11 timbl 388:
2.12 ! timbl 389: </PRE>end of HTAccess</BODY>
2.9 timbl 390: </HTML>
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