rat/lonpageflip.pm - view

File: [LON-CAPA] / rat / lonpageflip.pm
Revision 1.64: download - view: text, annotated - select for diffs
Thu Feb 23 19:29:26 2006 UTC (18 years, 2 months ago) by albertel
Branches: MAIN
CVS tags: HEAD

- need to check if
  - I can get to the resource through a valid forward path (check the condition_ for the res)
  - and if I can is this link a valid one to take

1: # The LearningOnline Network with CAPA 2: # 3: # Page flip handler 4: # 5: # $Id: lonpageflip.pm,v 1.64 2006/02/23 19:29:26 albertel Exp $ 6: # 7: # Copyright Michigan State University Board of Trustees 8: # 9: # This file is part of the LearningOnline Network with CAPA (LON-CAPA). 10: # 11: # LON-CAPA is free software; you can redistribute it and/or modify 12: # it under the terms of the GNU General Public License as published by 13: # the Free Software Foundation; either version 2 of the License, or 14: # (at your option) any later version. 15: # 16: # LON-CAPA is distributed in the hope that it will be useful, 17: # but WITHOUT ANY WARRANTY; without even the implied warranty of 18: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19: # GNU General Public License for more details. 20: # 21: # You should have received a copy of the GNU General Public License 22: # along with LON-CAPA; if not, write to the Free Software 23: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 24: # 25: # /home/httpd/html/adm/gpl.txt 26: # 27: # http://www.lon-capa.org/ 28: # 29: 30: package Apache::lonpageflip; 31: 32: use strict; 33: use Apache::Constants qw(:common :http REDIRECT); 34: use Apache::lonnet; 35: use HTML::TokeParser; 36: use GDBM_File; 37: 38: # ========================================================== Module Global Hash 39: 40: my %hash; 41: 42: sub cleanup { 43: if (tied(%hash)){ 44: &Apache::lonnet::logthis('Cleanup pageflip: hash'); 45: unless (untie(%hash)) { 46: &Apache::lonnet::logthis('Failed cleanup pageflip: hash'); 47: } 48: } 49: return OK; 50: } 51: 52: sub addrid { 53: my ($current,$new,$condid)=@_; 54: unless ($condid) { $condid=0; } 55: 56: if ($current) { 57: $current.=','.$new; 58: } else { 59: $current=''.$new; 60: } 61: 62: return $current; 63: } 64: 65: sub fullmove { 66: my ($rid,$mapurl,$direction)=@_; 67: if (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'.db', 68: &GDBM_READER(),0640)) { 69: ($rid,$mapurl)=&move($rid,$mapurl,$direction); 70: untie(%hash); 71: } 72: return($rid,$mapurl); 73: } 74: 75: sub hash_src { 76: my ($id)=@_; 77: my ($mapid,$resid)=split(/\./,$id); 78: my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid}, 79: $resid,$hash{'src_'.$id}); 80: if ($hash{'encrypted_'.$id}) { 81: return (&Apache::lonenc::encrypted($hash{'src_'.$id}), 82: &Apache::lonenc::encrypted($symb)); 83: } 84: return ($hash{'src_'.$id},$symb); 85: } 86: 87: sub move { 88: my ($rid,$mapurl,$direction)=@_; 89: my $startoutrid=$rid; 90: 91: my $next=''; 92: 93: my $mincond=1; 94: my $posnext=''; 95: if ($direction eq 'forward') { 96: # --------------------------------------------------------------------- Forward 97: while ($hash{'type_'.$rid} eq 'finish') { 98: $rid=$hash{'ids_'.$hash{'map_id_'.(split(/\./,$rid))[0]}}; 99: } 100: foreach my $id (split(/\,/,$hash{'to_'.$rid})) { 101: my $condition= $hash{'conditions_'.$hash{'goesto_'.$id}}; 102: my $rescond = &Apache::lonnet::docondval($condition); 103: my $linkcond = &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$id}}); 104: my $thiscond = ($rescond<$linkcond)?$rescond:$linkcond; 105: if ($thiscond>=$mincond) { 106: if ($posnext) { 107: $posnext.=','.$id.':'.$thiscond; 108: } else { 109: $posnext=$id.':'.$thiscond; 110: } 111: if ($thiscond>$mincond) { $mincond=$thiscond; } 112: } 113: } 114: foreach my $id (split(/\,/,$posnext)) { 115: my ($linkid,$condval)=split(/\:/,$id); 116: if ($condval>=$mincond) { 117: $next=&addrid($next,$hash{'goesto_'.$linkid}, 118: $hash{'condid_'.$hash{'undercond_'.$linkid}}); 119: } 120: } 121: if ($hash{'is_map_'.$next}) { 122: # This jumps to the beginning of a new map (going down level) 123: if ( 124: $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'sequence') { 125: $mapurl=$hash{'src_'.$next}; 126: $next=$hash{'map_start_'.$hash{'src_'.$next}}; 127: } elsif ( 128: # This jumps back up from an empty sequence, to a page up one level 129: $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'page') { 130: $mapurl=$hash{'map_id_'.(split(/\./,$next))[0]}; 131: } 132: } elsif 133: ((split(/\./,$startoutrid))[0]!=(split(/\./,$next))[0]) { 134: # This comes up from a map (coming up one level); 135: $mapurl=$hash{'map_id_'.(split(/\./,$next))[0]}; 136: } 137: } elsif ($direction eq 'back') { 138: # ------------------------------------------------------------------- Backwards 139: while ($hash{'type_'.$rid} eq 'start') { 140: $rid=$hash{'ids_'.$hash{'map_id_'.(split(/\./,$rid))[0]}}; 141: } 142: foreach my $id (split(/\,/,$hash{'from_'.$rid})) { 143: my $condition= $hash{'conditions_'.$hash{'comesfrom_'.$id}}; 144: my $rescond = &Apache::lonnet::docondval($condition); 145: my $linkcond = &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$id}}); 146: my $thiscond = ($rescond<$linkcond)?$rescond:$linkcond; 147: if ($thiscond>=$mincond) { 148: if ($posnext) { 149: $posnext.=','.$id.':'.$thiscond; 150: } else { 151: $posnext=$id.':'.$thiscond; 152: } 153: if ($thiscond>$mincond) { $mincond=$thiscond; } 154: } 155: } 156: foreach my $id (split(/\,/,$posnext)) { 157: my ($linkid,$condval)=split(/\:/,$id); 158: if ($condval>=$mincond) { 159: $next=&addrid($next,$hash{'comesfrom_'.$linkid}, 160: $hash{'condid_'.$hash{'undercond_'.$linkid}}); 161: } 162: } 163: if ($hash{'is_map_'.$next}) { 164: # This jumps to the end of a new map (going down one level) 165: if ( 166: $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'sequence') { 167: $mapurl=$hash{'src_'.$next}; 168: $next=$hash{'map_finish_'.$hash{'src_'.$next}}; 169: } elsif ( 170: $hash{'map_type_'.$hash{'map_pc_'.$hash{'src_'.$next}}} eq 'page') { 171: # This jumps back up from an empty sequence, to a page up one level 172: $mapurl=$hash{'map_id_'.(split(/\./,$next))[0]}; 173: } 174: } elsif 175: ((split(/\./,$startoutrid))[0]!=(split(/\./,$next))[0]) { 176: # This comes back up from a map (going up one level); 177: $mapurl=$hash{'map_id_'.(split(/\./,$next))[0]}; 178: } 179: } 180: return ($next,$mapurl); 181: } 182: 183: sub navlaunch { 184: my ($r)=@_; 185: &Apache::loncommon::content_type($r,'text/html'); 186: &Apache::loncommon::no_cache($r); 187: $r->send_http_header; 188: my $html=&Apache::lonxml::xmlbegin(); 189: $r->print("$html<head>\n"); 190: $r->print('</head>'. 191: &Apache::loncommon::bodytag('Launched')); 192: $r->print(<<ENDNAV); 193: <p><a href="/adm/flip?postdata=firstres%3a">Goto first resource</a></p> 194: <script type="text/javascript"> 195: function collapse() { 196: menu=window.open("/adm/navmaps?collapseExternal","loncapanav", 197: "height=600,width=400,scrollbars=1"); 198: this.document.location='/adm/navmaps?turningOffExternal'; 199: } 200: </script> 201: <p><a href="javascript:collapse();">Collapse external navigation window</a></p> 202: ENDNAV 203: $r->print(&Apache::loncommon::endbodytag().'</html>'); 204: } 205: # ================================================================ Main Handler 206: 207: sub handler { 208: my $r=shift; 209: 210: # ------------------------------------------- Set document type for header only 211: 212: if ($r->header_only) { 213: &Apache::loncommon::content_type($r,'text/html'); 214: $r->send_http_header; 215: return OK; 216: } 217: 218: my %cachehash=(); 219: my $multichoice=0; 220: my %multichoicehash=(); 221: my ($redirecturl,$redirectsymb); 222: my $next=''; 223: my @possibilities=(); 224: &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'},['postdata']); 225: if (($env{'form.postdata'})&&($env{'request.course.fn'})) { 226: $env{'form.postdata'}=~/(\w+)\:(.*)/; 227: my $direction=$1; 228: my $currenturl=$2; 229: if ($currenturl=~m|^/enc/|) { 230: $currenturl=&Apache::lonenc::unencrypted($currenturl); 231: } 232: $currenturl=~s/\.\d+\.(\w+)$/\.$1/; 233: if ($direction eq 'firstres') { 234: my $furl; 235: if (tie(my %bighash,'GDBM_File',$env{'request.course.fn'}.'.db', 236: &GDBM_READER(),0640)) { 237: $furl=$bighash{'first_url'}; 238: untie(%bighash); 239: } 240: &Apache::loncommon::content_type($r,'text/html'); 241: $r->header_out(Location => 242: 'http://'.$ENV{'HTTP_HOST'}.$furl); 243: 244: return REDIRECT; 245: } 246: if ($direction eq 'return' || $direction eq 'navlaunch') { 247: # -------------------------------------------------------- Return to last known 248: my $last; 249: if (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'_symb.db', 250: &GDBM_READER(),0640)) { 251: $last=$hash{'last_known'}; 252: untie(%hash); 253: } 254: my $newloc; 255: if (($last) && (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'.db', 256: &GDBM_READER(),0640))) { 257: my ($murl,$id,$fn)=&Apache::lonnet::decode_symb($last); 258: $id=$hash{'map_pc_'.&Apache::lonnet::clutter($murl)}.'.'.$id; 259: $newloc=$hash{'src_'.$id}; 260: if ($newloc) { 261: if ($hash{'encrypted_'.$id}) { $newloc=&Apache::lonenc::encrypted($newloc); } 262: 263: } else { 264: $newloc='/adm/navmaps'; 265: } 266: untie %hash; 267: } else { 268: $newloc='/adm/navmaps'; 269: } 270: if ($newloc eq '/adm/navmaps' && $direction eq 'navlaunch') { 271: &navlaunch($r); 272: return OK; 273: } else { 274: &Apache::loncommon::content_type($r,'text/html'); 275: $r->header_out(Location => 276: 'http://'.$ENV{'HTTP_HOST'}.$newloc); 277: 278: return REDIRECT; 279: } 280: } 281: $currenturl=~s/^http\:\/\///; 282: $currenturl=~s/^[^\/]+//; 283: # 284: # Is the current URL on the map? If not, start with last known URL 285: # 286: unless (&Apache::lonnet::is_on_map($currenturl)) { 287: my $last; 288: if (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'_symb.db', 289: &GDBM_READER(),0640)) { 290: $last=$hash{'last_known'}; 291: untie(%hash); 292: } 293: if ($last) { 294: $currenturl=&Apache::lonnet::clutter((&Apache::lonnet::decode_symb($last))[2]); 295: } else { 296: if ($direction eq 'return') { 297: &Apache::loncommon::content_type($r,'text/html'); 298: $r->header_out(Location => 299: 'http://'.$ENV{'HTTP_HOST'}.'/adm/noidea.html'); 300: return REDIRECT; 301: } else { 302: &navlaunch($r); 303: return OK; 304: } 305: } 306: } 307: # ------------------------------------------- Do we have any idea where we are? 308: my $position; 309: if ($position=Apache::lonnet::symbread($currenturl)) { 310: # ------------------------------------------------------------------------- Yes 311: my ($startoutmap,$mapnum,$thisurl)=&Apache::lonnet::decode_symb($position); 312: $cachehash{$startoutmap}{$thisurl}=[$thisurl,$mapnum]; 313: $cachehash{$startoutmap}{'last_known'}= 314: [&Apache::lonnet::declutter($currenturl),$mapnum]; 315: 316: # ============================================================ Tie the big hash 317: if (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'.db', 318: &GDBM_READER(),0640)) { 319: my $rid=$hash{'map_pc_'.&Apache::lonnet::clutter($startoutmap)}. 320: '.'.$mapnum; 321: 322: # ------------------------------------------------- Move forward, backward, etc 323: my $endupmap; 324: ($next,$endupmap)=&move($rid,$startoutmap,$direction); 325: # -------------------------------------- Do we have one and only one empty URL? 326: my $safecount=0; 327: while (($next) && ($next!~/\,/) && 328: ((!$hash{'src_'.$next}) || 329: ((!$env{'request.role.adv'}) && $hash{'randomout_'.$next})) 330: && ($safecount<10000)) { 331: ($next,$endupmap)=&move($next,$endupmap,$direction); 332: $safecount++; 333: } 334: # We are now at at least one non-empty URL 335: # ----------------------------------------------------- Check out possibilities 336: if ($next) { 337: @possibilities=split(/\,/,$next); 338: if ($#possibilities==0) { 339: # ---------------------------------------------- Only one possibility, redirect 340: ($redirecturl,$redirectsymb)=&hash_src($next); 341: $cachehash{$endupmap}{$redirecturl}= 342: [$redirecturl,(split(/\./,$next))[1]]; 343: } else { 344: # ------------------------ There are multiple possibilities for a next resource 345: $multichoice=1; 346: foreach my $id (@possibilities) { 347: $multichoicehash{'src_'.$id}=$hash{'src_'.$id}; 348: $multichoicehash{'title_'.$id}=$hash{'title_'.$id}; 349: $multichoicehash{'type_'.$id}=$hash{'type_'.$id}; 350: (my $first, my $second) = $id =~ /(\d+).(\d+)/; 351: my $symbSrc = Apache::lonnet::declutter($hash{'src_'.$id}); 352: $multichoicehash{'symb_'.$id} = 353: Apache::lonnet::declutter($hash{'map_id_'.$first}.'___'. 354: $second.'___'.$symbSrc); 355: 356: my ($choicemap,$choiceres)=split(/\./,$id); 357: my $map=&Apache::lonnet::declutter($hash{'src_'.$choicemap}); 358: my $url=$multichoicehash{'src_'.$id}; 359: $cachehash{$map}{$url}=[$url,$choiceres]; 360: } 361: } 362: } else { 363: # -------------------------------------------------------------- No place to go 364: $multichoice=-1; 365: } 366: # ----------------- The program must come past this point to untie the big hash 367: untie(%hash); 368: # --------------------------------------------------------- Store position info 369: $cachehash{$startoutmap}{'last_direction'}=[$direction,'notasymb']; 370: foreach my $thismap (keys %cachehash) { 371: my $mapnum=$cachehash{$thismap}->{'mapnum'}; 372: delete($cachehash{$thismap}->{'mapnum'}); 373: &Apache::lonnet::symblist($thismap, 374: %{$cachehash{$thismap}}); 375: } 376: # ============================================== Do not return before this line 377: if ($redirecturl) { 378: # ----------------------------------------------------- There is a URL to go to 379: if ($direction eq 'forward') { 380: &Apache::lonnet::linklog($currenturl,$redirecturl); 381: } 382: if ($direction eq 'back') { 383: &Apache::lonnet::linklog($redirecturl,$currenturl); 384: } 385: # ------------------------------------------------- Check for critical messages 386: if ((time-$env{'user.criticalcheck.time'})>300) { 387: my @what=&Apache::lonnet::dump 388: ('critical',$env{'user.domain'}, 389: $env{'user.name'}); 390: if ($what[0]) { 391: if (($what[0] ne 'con_lost') && 392: ($what[0]!~/^error\:/)) { 393: $redirecturl='/adm/email?critical=display'; 394: $redirectsymb=''; 395: } 396: } 397: &Apache::lonnet::appenv('user.criticalcheck.time'=>time); 398: } 399: 400: &Apache::loncommon::content_type($r,'text/html'); 401: my $url='http://'.$ENV{'HTTP_HOST'}.$redirecturl; 402: if ($redirectsymb ne '') { $url.='?symb='.&Apache::lonnet::escape($redirectsymb); } 403: $r->header_out(Location => $url); 404: return REDIRECT; 405: } else { 406: # --------------------------------------------------------- There was a problem 407: &Apache::loncommon::content_type($r,'text/html'); 408: $r->send_http_header; 409: my %lt=&Apache::lonlocal::texthash('title' => 'End of Sequence', 410: 'explain' => 411: 'You have reached the end of the sequence of materials.', 412: 'back' => 'Go Back', 413: 'nav' => 'Navigate Course Content', 414: 'wherenext' => 415: 'There are several possibilities of where to go next', 416: 'pick' => 417: 'Please click on the the resource you intend to access', 418: 'titleheader' => 'Title', 419: 'type' => 'Type'); 420: if ($#possibilities>0) { 421: my $bodytag= 422: &Apache::loncommon::bodytag('Multiple Resources'); 423: $r->print(<<ENDSTART); 424: <head><title>Choose Next Location</title></head> 425: $bodytag 426: <h3>$lt{'wherenext'}</h3> 427: <p> 428: $lt{'pick'}: 429: <p> 430: <table border=2> 431: <tr><th>$lt{'titleheader'}</th><th>$lt{'type'}</th></tr> 432: ENDSTART 433: foreach my $id (@possibilities) { 434: $r->print( 435: '<tr><td><a href="'. 436: $multichoicehash{'src_'.$id}.'?symb=' . 437: Apache::lonnet::escape($multichoicehash{'symb_'.$id}).'">'. 438: $multichoicehash{'title_'.$id}. 439: '</a></td><td>'.$multichoicehash{'type_'.$id}. 440: '</td></tr>'); 441: } 442: $r->print('</table>'); 443: } else { 444: my $bodytag=&Apache::loncommon::bodytag('No Resource'); 445: $r->print(<<ENDNONE); 446: <head><title>No Resource</title></head> 447: $bodytag 448: <h3>$lt{'title'}</h3> 449: <p>$lt{'explain'}</p> 450: ENDNONE 451: } 452: $r->print(<<ENDMENU); 453: <ul> 454: <li><a href="/adm/flip?postdata=return:">$lt{'back'}</a></li> 455: <li><a href="/adm/navmaps">$lt{'nav'}</a></li> 456: </ul></body></html> 457: ENDMENU 458: return OK; 459: } 460: } else { 461: # ------------------------------------------------- Problem, could not tie hash 462: $env{'user.error.msg'}="/adm/flip:bre:0:1:Course Data Missing"; 463: return HTTP_NOT_ACCEPTABLE; 464: } 465: } else { 466: # ---------------------------------------- No, could not determine where we are 467: $r->internal_redirect('/adm/ambiguous'); 468: } 469: } else { 470: # -------------------------- Class was not initialized or page fliped strangely 471: $env{'user.error.msg'}="/adm/flip:bre:0:0:Choose Course"; 472: return HTTP_NOT_ACCEPTABLE; 473: } 474: } 475: 476: 1; 477: __END__ 478: 479: 480: 481: 482: 483: 484: