1: # The LearningOnline Network with CAPA
2: # XML Parser Module
3: #
4: # last modified 06/26/00 by Alexander Sakharuk
5:
6: package Apache::lonxml;
7:
8: use strict;
9: use HTML::TokeParser;
10: use Safe;
11:
12: sub register {
13: my $space;
14: my @taglist;
15: my $temptag;
16: ($space,@taglist) = @_;
17: foreach $temptag (@taglist) {
18: $Apache::lonxml::alltags{$temptag}=$space;
19: }
20: }
21:
22: use Apache::style;
23: use Apache::lontexconvert;
24: use Apache::run;
25: use Apache::londefdef;
26: use Apache::scripttag;
27: #================================================== Main subroutine: xmlparse
28:
29: sub xmlparse {
30:
31: my ($target,$content_file_string,%style_for_target) = @_;
32: my $pars = HTML::TokeParser->new(\$content_file_string);
33: my $currentstring = '';
34: my $finaloutput = '';
35: my $newarg = '';
36: my $safeeval = new Safe;
37: $safeeval->permit("entereval");
38: #-------------------- Redefinition of the target in the case of compound target
39:
40: ($target, my @tenta) = split('&&',$target);
41:
42: #------------------------- Stack definition (in stack we have all current tags)
43:
44: my @stack = ();
45: my @parstack = ();
46:
47: #------------------------------------- Parse input string (content_file_string)
48:
49: my $token;
50:
51: while ($token = $pars->get_token) {
52: if ($token->[0] eq 'T') {
53: $finaloutput .= &Apache::run::evaluate($token->[1],$safeeval,'');
54: } elsif ($token->[0] eq 'S') {
55: # add tag to stack
56: push (@stack,$token->[1]);
57: # add parameters list to another stack
58: push (@parstack,&parstring($token));
59:
60: if (exists $style_for_target{$token->[1]}) {
61: #basically recurse, but we never got more than one level down so just
62: #create the new context here
63: my @innerstack = ();
64: my @innerparstack = ();
65: # use style file definition
66: $newarg = $style_for_target{$token->[1]};
67: my $pat = HTML::TokeParser->new(\$newarg);
68: my $tokenpat = '';
69: my $partstring = '';
70:
71: while ($tokenpat = $pat->get_token) {
72: if ($tokenpat->[0] eq 'T') {
73: $partstring = $tokenpat->[1];
74: } elsif ($tokenpat->[0] eq 'S') {
75: push (@innerstack,$tokenpat->[1]);
76: push (@innerparstack,&parstring($tokenpat));
77: $partstring = &callsub("start_$tokenpat->[1]",
78: $target, $tokenpat, \@innerparstack,
79: $pat, $safeeval);
80: } elsif ($tokenpat->[0] eq 'E') {
81: #clear out any tags that didn't end
82: while ($tokenpat->[1] ne $innerstack[$#innerstack]
83: && ($#innerstack > 0)) {pop @innerstack;pop @innerparstack;}
84: $partstring = &callsub("end_$tokenpat->[1]",
85: $target, $tokenpat, \@innerparstack,
86: $pat, $safeeval);
87: }
88: #pass both the variable to the style tag, and the tag we
89: #are processing inside the <definedtag>
90: $finaloutput .= &Apache::run::evaluate($partstring,$safeeval,
91: $parstack[$#parstack].$innerparstack[$#innerparstack]);
92: if ($tokenpat->[0] eq 'E') { pop @innerstack;pop @innerparstack; }
93: }
94: } else {
95: my $result = &callsub("start_$token->[1]", $target, $token,\@parstack,
96: $pars, $safeeval);
97: $finaloutput .= &Apache::run::evaluate($result,$safeeval,
98: $parstack[$#parstack]);
99: }
100: } elsif ($token->[0] eq 'E') {
101: #clear out any tags that didn't end
102: while ($token->[1] ne $stack[$#stack]
103: && ($#stack > 0)) {pop @stack;pop @parstack;}
104:
105: if (exists $style_for_target{'/'."$token->[1]"}) {
106: my @innerstack = ();
107: my @innerparstack = ();
108: $newarg = $style_for_target{'/'."$token->[1]"};
109: my $pat = HTML::TokeParser->new(\$newarg);
110: my $tokenpat;
111: my $partstring = '';
112:
113: while ($tokenpat = $pat->get_token) {
114: if ($tokenpat->[0] eq 'T') {
115: $partstring .= $tokenpat->[1];
116: } elsif ($tokenpat->[0] eq 'S') {
117: push (@innerstack,$tokenpat->[1]);
118: push (@innerparstack,&parstring($tokenpat));
119: $partstring = &callsub("start_$tokenpat->[1]",
120: $target, $tokenpat, \@innerparstack,
121: $pat, $safeeval);
122: } elsif ($tokenpat->[0] eq 'E') {
123: #clear out any tags that didn't end
124: while ($tokenpat->[1] ne $innerstack[$#innerstack]
125: && ($#innerstack > 0)) {pop @innerstack;pop @innerparstack;}
126: $partstring = &callsub("end_$tokenpat->[1]",
127: $target, $tokenpat, \@innerparstack,
128: $pat, $safeeval);
129: }
130: #pass both the variable to the style tag, and the tag we
131: #are processing inside the <definedtag>
132: $finaloutput .= &Apache::run::evaluate($partstring,$safeeval,
133: $parstack[$#parstack].$innerparstack[$#innerparstack]);
134: if ($tokenpat->[0] eq 'E') { pop @innerstack;pop @innerparstack; }
135: }
136: } else {
137: my $result = &callsub("end_$token->[1]", $target, $token, \@parstack,
138: $pars,$safeeval);
139: $finaloutput .= &Apache::run::evaluate($result,$safeeval,
140: $parstack[$#parstack]);
141: }
142: pop @stack;
143: pop @parstack;
144: }
145: }
146: return $finaloutput;
147: }
148:
149: sub callsub {
150: my ($sub,$target,$token,$parstack,$parser,$safeeval)=@_;
151: my $currentstring='';
152: {
153: no strict 'refs';
154: if (my $space=$Apache::lonxml::alltags{$token->[1]}) {
155: #print "Calling sub $sub in $space \n";
156: $sub="$space\:\:$sub";
157: $currentstring = &$sub($target,$token,\@$parstack,$parser,$safeeval);
158: } else {
159: #print "NOT Calling sub $sub\n";
160: if (defined($token->[4])) {
161: $currentstring = $token->[4];
162: } else {
163: $currentstring = $token->[2];
164: }
165: }
166: use strict 'refs';
167: }
168: return $currentstring;
169: }
170:
171: sub parstring {
172: my ($token) = @_;
173: my $temp='';
174: map {$temp .= "my \$$_=\"$token->[2]->{$_}\";"} @{$token->[3]};
175: return $temp;
176: }
177: 1;
178: __END__
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