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HTML_img mode ("images" mode in the HTML interface) now uses dvipng to
generate images. ProblemSet now has a link to Hardcopy.
-sam
1 ################################################################################ 2 # WeBWorK mod_perl (c) 2000-2002 WeBWorK Project 3 # $Id$ 4 ################################################################################ 5 6 package WeBWorK::ContentGenerator; 7 8 =head1 NAME 9 10 WeBWorK::ContentGenerator - base class for modules that generate page content. 11 12 =cut 13 14 use strict; 15 use warnings; 16 use Apache::Constants qw(:common); 17 use CGI qw(); 18 use URI::Escape; 19 use WeBWorK::DB::Auth; 20 use WeBWorK::Utils qw(readFile); 21 #use CGI::Carp qw(fatalsToBrowser); 22 23 ################################################################################ 24 # This is a very unruly file, so I'm going to use very large comments to divide 25 # it into logical sections. 26 ################################################################################ 27 28 # new(Apache::Request, WeBWorK::CourseEnvironment) - create a new instance of a 29 # content generator. Usually only called by the dispatcher, although one might 30 # be able to use it for things like "sub-requests". Uh... uh... I have to think 31 # about that one. The dispatcher uses this idiom: 32 # 33 # 34 # WeBWorK::ContentGenerator::WHATEVER->new($r, $ce)->go(@whatever); 35 # 36 # and throws away the result ;) 37 # 38 sub new($$$) { 39 my $invocant = shift; 40 my $class = ref($invocant) || $invocant; 41 my $self = {}; 42 ($self->{r}, $self->{courseEnvironment}) = @_; 43 bless $self, $class; 44 return $self; 45 } 46 47 ################################################################################ 48 # Invocation and template processing 49 ################################################################################ 50 51 # go(@otherArguments) - render a page, using methods from the particular 52 # subclass of ContentGenerator. @otherArguments is passed to each method, so 53 # that the dispatcher can pass CG-specific data. The order of calls looks like 54 # this: 55 # 56 # * &pre_header_initialize - give subclasses a chance to do initialization 57 # necessary for generating the HTTP header. 58 # * &header - this class provides a standard HTTP header with Content-Type 59 # text/html. Subclasses are welcome to overload this for things like 60 # an image-creation content generator or a PDF generator. 61 # * &initialize - let subclasses do post-header initialization. 62 # * any "template escapes" defined in the system template and supported by 63 # the subclass. Generic implementations of &title and &body are provided. 64 # 65 sub go { 66 my $self = shift; 67 my $r = $self->{r}; 68 my $courseEnvironment = $self->{courseEnvironment}; 69 70 $self->pre_header_initialize(@_) if $self->can("pre_header_initialize"); 71 $self->header(@_); 72 return OK if $r->header_only; 73 74 $self->initialize(@_) if $self->can("initialize"); 75 $self->template($courseEnvironment->{templates}->{system}, @_); 76 77 return OK; 78 } 79 80 # template(STRING, @otherArguments) - parse a template, looking for escapes of 81 # the form <!--#NAME ARG1="FOO" ARG2="BAR"--> and calling a member function NAME 82 # (if available) for each NAME. The escapes are called like: 83 # 84 # $self->NAME(@otherArguments, \%escapeArguments) 85 # 86 # where @otherArguments originates in the dispatcher and %escapeArguments is 87 # parsed out of the escape itself (i.e. ARG1 => FOO, ARG2 => BAR) 88 # 89 sub template { 90 my ($self, $templateFile) = (shift, shift); 91 my $r = $self->{r}; 92 my $courseEnvironment = $self->{courseEnvironment}; 93 my @ifstack = (1); # Start off in printing mode 94 # say $ifstack[-1] to get the result of the last <#!--if--> 95 96 # so even though the variable $/ APPEARS to contain a newline, 97 # <TEMPLATE> is slurping the whole file into the first element of 98 # @template ONLY AFTER THE TRANSLATOR RUNS. WTF!!! 99 # 100 #open(TEMPLATE, $templateFile) or die "Couldn't open template $templateFile"; 101 #my @template = <TEMPLATE>; 102 #close TEMPLATE; 103 # 104 # Let's try something else instead: 105 my @template = split /\n/, readFile($templateFile); 106 107 foreach my $line (@template) { 108 #warn "foo: $line\n"; 109 # This is incremental regex processing. 110 # the /c is so that pos($line) doesn't die when the regex fails. 111 while ($line =~ m/\G(.*?)<!--#(\w*)((?:\s+.*?)?)-->/gc) { 112 my ($before, $function, $raw_args) = ($1, $2, $3); 113 # $args here will be a hashref 114 my @args = $raw_args =~ /\S/ ? cook_args($raw_args) : {}; 115 if ($ifstack[-1]) { 116 print $before; 117 } 118 119 if ($self->can($function)) { 120 if ($function eq "if") { 121 push @ifstack, $self->$function(@_, [@args]); 122 } elsif ($function eq "else" and @ifstack > 1) { 123 $ifstack[-1] = not $ifstack[-1]; 124 } elsif ($function eq "endif" and @ifstack > 1) { 125 pop @ifstack; 126 } elsif ($ifstack[-1]) { 127 print $self->$function(@_, {@args}); 128 } 129 } 130 } 131 132 if ($ifstack[-1]) { 133 print substr $line, (defined pos $line) ? pos $line : 0; 134 } 135 } 136 } 137 138 # cook_args(STRING) - parses a string of the form ARG1="FOO" ARG2="BAR". Returns 139 # a list which pairs into key/values and fits nicely in {}s. 140 # 141 sub cook_args($) { 142 my ($raw_args) = @_; 143 my @args = (); 144 145 # Boy I love m//g in scalar context! Go read the camel book, heathen. 146 # First, get the whole token with the quotes on both ends... 147 while ($raw_args =~ m/\G\s*(\w*)="((?:[^"\\]|\\.)*)"/g) { 148 my ($key, $value) = ($1, $2); 149 # ... then, rip out all the protecty backspaces 150 $value =~ s/\\(.)/$1/g; 151 push @args, $key => $value; 152 } 153 154 return @args; 155 } 156 157 ################################################################################ 158 # Macros used by content generators to render common idioms 159 ################################################################################ 160 161 # pathMacro(HASHREF, LIST) - helper macro for <!--#path--> escape: the hash 162 # reference contains the "style", "image", and "text" arguments to the escape. 163 # The LIST consists of ordered key-value pairs of the form: 164 # 165 # "Page Name" => URL 166 # 167 # If the page should not have a link associated with it, the URL should be left 168 # empty. Authentication data is added to the URL so you don't have to. A fully- 169 # formed path line is returned, suitable for returning by a function 170 # implementing the #path escape. 171 # 172 sub pathMacro { 173 my $self = shift; 174 my %args = %{ shift() }; 175 my @path = @_; 176 my $sep; 177 if ($args{style} eq "image") { 178 $sep = CGI::img({-src=>$args{image}, -alt=>$args{text}}); 179 } else { 180 $sep = $args{text}; 181 } 182 my $auth = $self->url_authen_args; 183 my @result; 184 while (@path) { 185 my $name = shift @path; 186 my $url = shift @path; 187 push @result, $url 188 ? CGI::a({-href=>"$url?$auth"}, $name) 189 : $name; 190 } 191 return join($sep, @result), "\n"; 192 } 193 194 sub siblingsMacro { 195 my $self = shift; 196 my @siblings = @_; 197 my $sep = CGI::br(); 198 my $auth = $self->url_authen_args; 199 my @result; 200 while (@siblings) { 201 my $name = shift @siblings; 202 my $url = shift @siblings; 203 push @result, $url 204 ? CGI::a({-href=>"$url?$auth"}, $name) 205 : $name; 206 } 207 return join($sep, @result), "\n"; 208 } 209 210 sub navMacro { 211 my $self = shift; 212 my %args = %{ shift() }; 213 my @links = @_; 214 my $auth = $self->url_authen_args; 215 my @result; 216 while (@links) { 217 my $name = shift @links; 218 my $url = shift @links; 219 push @result, $url 220 ? CGI::a({-href=>"$url?$auth"}, $name) 221 : $name; 222 } 223 return join($args{separator}, @result), "\n"; 224 } 225 226 # hidden_fields(LIST) - return hidden <INPUT> tags for each field mentioned in 227 # LIST (or all fields if list is empty), taking data from the current request. 228 # 229 sub hidden_fields($;@) { 230 my $self = shift; 231 my $r = $self->{r}; 232 my @fields = @_; 233 @fields or @fields = $r->param; 234 my $courseEnvironment = $self->{courseEnvironment}; 235 my $html = ""; 236 237 foreach my $param (@fields) { 238 my $value = $r->param($param); 239 $html .= CGI::input({-type=>"hidden",-name=>"$param",-value=>"$value"}); 240 } 241 return $html; 242 } 243 244 # hidden_authen_fields() - use hidden_fields to return hidden <INPUT> tags for 245 # request fields used in authentication. 246 # 247 sub hidden_authen_fields($) { 248 my $self = shift; 249 return $self->hidden_fields("user","effectiveUser","key"); 250 } 251 252 # url_args(LIST) - return a URL query string (without the leading `?') 253 # containing values for each field mentioned in LIST, or all fields if list is 254 # empty. Data is taken from the current request. 255 # 256 sub url_args($;@) { 257 my $self = shift; 258 my $r = $self->{r}; 259 my @fields = @_; 260 @fields or @fields = $r->param; 261 my $courseEnvironment = $self->{courseEnvironment}; 262 263 my @pairs; 264 foreach my $param (@fields) { 265 my $value = $r->param($param) || ""; 266 push @pairs, uri_escape($param) . "=" . uri_escape($value); 267 } 268 269 return join("&", @pairs); 270 } 271 272 # url_authen_args() - use url_args to return a URL query string for request 273 # fields used in authentication. 274 # 275 sub url_authen_args($) { 276 my $self = shift; 277 my $r = $self->{r}; 278 return $self->url_args("user","effectiveUser","key"); 279 } 280 281 # print_form_data(BEGIN, MIDDLE, END, OMIT) - return a string containing request 282 # fields not matched by OMIT, placing BEGIN before each field name, MIDDLE 283 # between each field and its value, and END after each value. Values are taken 284 # from the current request. OMIT is a quoted reguar expression. 285 # 286 sub print_form_data { 287 my ($self, $begin, $middle, $end, $qr_omit) = @_; 288 my $return_string = ""; 289 my $r=$self->{r}; 290 my @form_data = $r->param; 291 foreach my $name (@form_data) { 292 next if ($qr_omit and $name =~ /$qr_omit/); 293 my @values = $r->param($name); 294 foreach my $variable (qw(begin name middle value end)) { 295 no strict 'refs'; 296 ${$variable} = "" unless defined ${$variable}; 297 } 298 foreach my $value (@values) { 299 $return_string .= "$begin$name$middle$value$end"; 300 } 301 } 302 return $return_string; 303 } 304 305 ################################################################################ 306 # Generic versions of template escapes 307 ################################################################################ 308 309 # Reminder: here are the template functions currently defined: 310 # 311 # path 312 # style = text|image 313 # image = URL of image 314 # text = text separator 315 # links 316 # siblings 317 # nav 318 # style = text|image 319 # imageprefix = prefix to image URL 320 # imagesuffix = suffix to image URL 321 # separator = HTML to place in between links 322 # title 323 # body 324 325 sub header { 326 my $self = shift; 327 my $r = $self->{r}; 328 $r->content_type('text/html'); 329 $r->send_http_header(); 330 } 331 332 # drunk code. rewrite. 333 sub links { 334 my $self = shift; 335 my $ce = $self->{courseEnvironment}; 336 my $userName = $self->{r}->param("user"); 337 my $courseName = $ce->{courseName}; 338 my $root = $ce->{webworkURLs}->{root}; 339 my $permLevel = WeBWorK::DB::Auth->new($ce)->getPermissions($userName); 340 341 my $probSets = "$root/$courseName/?" . $self->url_authen_args(); 342 my $prefs = "$root/$courseName/prefs/?" . $self->url_authen_args(); 343 my $prof = "$root/$courseName/prof/?" . $self->url_authen_args(); 344 my $profLine; 345 if ($permLevel > 0) { 346 $profLine = CGI::a({-href=>$prof}, "Professor") . CGI::br(), 347 } 348 my $help = $ce->{webworkURLs}->{docs} . "?" . $self->url_authen_args(); 349 my $logout = "$root/$courseName/?user=$userName"; 350 351 return 352 CGI::a({-href=>$probSets}, "Problem Sets"), CGI::br(), 353 CGI::a({-href=>$prefs}, "User Options"), CGI::br(), 354 $profLine, 355 CGI::a({-href=>$help}, "Help"), CGI::br(), 356 CGI::a({-href=>$logout}, "Log Out"), CGI::br(), 357 ; 358 } 359 360 # This is different. It probably should print anything (except in debugging cases) 361 # and it should return a boolean, not a string. &if is called in a nonstandard way 362 # by &template, with $args as an arrayref instead of a hashref. this is a hack! yay! 363 364 # OK, this is a pluggin architecture. it iterates through attributes of the "if" tag, 365 # and for each predicate $p, it calls &if_$p in an object-oriented way, continuing the 366 # grand templating theme of an object-oriented pluggable architecture using ->can($). 367 sub if { 368 my ($self, $args) = @_[0,-1]; 369 # A single if "or"s it's components. Nesting produces "and". 370 371 my @args = @$args; # Hahahahaha, get it?! 372 373 if (@args % 2 != 0) { 374 # flip out and kill people, but do not commit seppuku 375 print '<!--&if recieved an uneven number of arguments. This shouldn\'t happen, but I\'ll let it slide.-->\n'; 376 } 377 378 while (@args > 1) { 379 my ($key, $value) = (shift @args, shift @args); 380 381 # a non-existent &if_$key is the same as a false result, but we're ORing, so it's OK 382 my $sub = "if_$key"; # perl doesn't like it when you try to construct a string right in a method invocation 383 if ($self->can("if_$key") and $self->$sub("$value")) { 384 return 1; 385 } 386 } 387 388 return 0; 389 } 390 391 # &if_can will return 1 if the current object->can("do $_[1]") 392 sub if_can ($$) { 393 my ($self, $arg) = (@_); 394 395 if ($self->can("$arg")) { 396 return 1; 397 } else { 398 return 0; 399 } 400 } 401 402 1; 403 404 __END__ 405 406 =head1 AUTHOR 407 408 Written by Dennis Lambe Jr., malsyned (at) math.rochester.edu 409 and Sam Hathaway, sh002i (at) math.rochester.edu. 410 411 =cut
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