rat/lonsequence.pm - view

File: [LON-CAPA] / rat / lonsequence.pm
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Mon Oct 16 21:09:33 2000 UTC (23 years, 6 months ago) by www
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Try to find out where coming from (last page or first page wanted?)

1: # The LearningOnline Network with CAPA 2: # 3: # Sequence Handler 4: # 5: # (Handler to resolve ambiguous file locations 6: # 7: # (TeX Content Handler 8: # 9: # 05/29/00,05/30,10/11 Gerd Kortemeyer) 10: # 11: # 10/11,10/12 Gerd Kortemeyer) 12: # 13: # 10/16 Gerd Kortemeyer 14: 15: package Apache::lonambiguous; 16: 17: use strict; 18: use Apache::lonnet; 19: use Apache::Constants qw(:common REDIRECT); 20: use GDBM_File; 21: 22: 23: # ----------------------------------------------------------- Could not resolve 24: 25: sub getlost { 26: my ($r,$errmsg)=@_; 27: $r->content_type('text/html'); 28: $r->send_http_header; 29: $r->print( 30: '<head><title>Unknown Error</title></head><body bgcolor="#FFFFFF"><h1>'. 31: 'LON-CAPA</h1>Could not handle ambiguous resource reference.<p>'.$errmsg. 32: '</body></html>'); 33: } 34: 35: # ================================================================ Main Handler 36: 37: sub handler { 38: my $r=shift; 39: 40: if ($r->header_only) { 41: $r->content_type('text/html'); 42: $r->send_http_header; 43: return OK; 44: } 45: 46: my %hash; 47: my %bighash; 48: my $requrl=$r->uri; 49: 50: # ----------------------------------------------------------------- Tie db file 51: if ($ENV{'request.course.fn'}) { 52: my $last; 53: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db', 54: &GDBM_READER,0640)) { 55: $last=$hash{'last_direction'}; 56: untie(%hash); 57: } 58: if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db', 59: &GDBM_READER,0640)) { 60: my $direction=''; 61: my $prevmap=''; 62: if ($last) { 63: ($prevmap,$direction)=(split(/\_\_\_/,$last)); 64: } 65: 66: # ===== Stuff goes here 67: foreach $envkey (keys %ENV) { 68: if ($envkey=~/^form\.(\d+)\.(\d+)$/) { 69: my $mapid=$1; 70: my $resid=$2; 71: my $resurl=$bighash{'src_'.$mapid.'.'.$resid}; 72: &Apache::lonnet::symblist($bighash{'map_id_'.$mapid}, 73: $resurl => $resid); 74: $r->header_out(Location => 75: 'http://'.$ENV{'HTTP_HOST'}.$resurl); 76: return REDIRECT; 77: } 78: } 79: untie(%bighash); 80: } else { 81: &getlost($r,'Could not access course structure.'); 82: return OK; 83: } 84: } else { 85: $ENV{'user.error.msg'}="$requrl:bre:0:0:Course not initialized"; 86: return HTTP_NOT_ACCEPTABLE; 87: } 88: 89: return OK; 90: 91: # ================================================================= TRASH BELOW 92: 93: # ---------------------------------------------------------- Do we have a case? 94: 95: my $thisfn; 96: unless (($thisfn=$ENV{'request.ambiguous'})&&($ENV{'request.course.fn'})) { 97: &getlost($r,'Could not find information on resource.'); 98: return OK; 99: } 100: 101: # ---------------------------------- Should this file have been part of a page? 102: 103: $thisfn=&Apache::lonnet::declutter($thisfn); 104: my %hash; 105: my $syval=''; 106: 107: if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db', 108: &GDBM_READER,0640)) { 109: $syval=$hash{$thisfn}; 110: untie(%hash); 111: } 112: 113: # ---------------------------------------------------------- There was an entry 114: 115: if ($syval) { 116: 117: if ($syval=~/\_$/) { 118: # ----------------------------------- Okay, this should have appeared on a page 119: $syval=~s/\_\_\_$//; 120: $r->content_type('text/html'); 121: $r->header_out(Location => 122: 'http://'.$ENV{'HTTP_HOST'}.'/res/'.$syval); 123: return REDIRECT; 124: } else { 125: # There is not really a problem (???), but cannot go back without endless loop 126: &getlost($r,'The nature of the problem is unclear'); 127: return OK; 128: } 129: } 130: 131: # ------------------------------------------------ Would be standalone resource 132: 133: if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db', 134: &GDBM_READER,0640)) { 135: # ---------------------------------------------- Get ID(s) for current resource 136: my $ids=$bighash{'ids_/res/'.$thisfn}; 137: if ($ids) { 138: # ------------------------------------------------------------------- Has ID(s) 139: my @possibilities=split(/\,/,$ids); 140: my $couldbe=''; 141: map { 142: if (&Apache::lonnet::allowed('bre',$bighash{'src_'.$_})) { 143: if ($couldbe) { 144: $couldbe.=','.$_; 145: } else { 146: $couldbe=$_; 147: } 148: } 149: } @possibilities; 150: if ($couldbe) { 151: @possibilities=split(/\,/,$couldbe); 152: if ($#possibilities>0) { 153: # ----------------------------------------------- Okay, really multiple choices 154: $r->content_type('text/html'); 155: $r->send_http_header; 156: $r->print(<<ENDSTART); 157: <head><title>Choose Location</title></head> 158: <body bgcolor="#FFFFFF"> 159: <h1>LON-CAPA</h1> 160: The resource you had been accessing appears more than once in this course, 161: and LON-CAPA has insufficient session information to determine which instance 162: of the resource you meant. 163: <p> 164: Please click on the instance of the resource you intended to access: 165: <p> 166: <form action="/adm/ambiguous" method=post> 167: <input type=hidden name=orgurl value="$thisfn"> 168: <input type=hidden name=selecturl value=1> 169: <table border=2> 170: <tr><th> </th><th>Title</th><th>Type</th><th>Part of ...</th></tr> 171: ENDSTART 172: map { 173: my $mapurl=$bighash{'map_id_'.(split(/\./,$_))[0]}; 174: $r->print('<tr><td><input type=submit value=Select name="'. 175: $_.'"></td><td>'.$bighash{'title_'.$_}. 176: '</td><td>'.$bighash{'type_'.$_}. 177: '</td><td><a href="'.$mapurl.'">'.$mapurl. 178: '</a></td></tr>'); 179: } @possibilities; 180: $r->print('</table></form></body></html>'); 181: untie(%bighash); 182: return OK; 183: } 184: } 185: } 186: untie(%bighash); 187: } 188: 189: # ------------------------------------ This handler should not have been called 190: &getlost($r,'Invalid call of handler'); 191: return OK; 192: } 193: 194: 1; 195: __END__ 196: 197: 198: 199: 200: 201: 202: