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- moved errorOutput and warningOutput into ContentGenerator - worked on Harcopy -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 Carp qw(cluck); 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 # This is incremental regex processing. 109 # the /c is so that pos($line) doesn't die when the regex fails. 110 while ($line =~ m/\G(.*?)<!--#(\w*)((?:\s+.*?)?)-->/gc) { 111 my ($before, $function, $raw_args) = ($1, $2, $3); 112 my @args = ($raw_args =~ /\S/) ? cook_args($raw_args) : (); 113 114 if ($ifstack[-1]) { 115 print $before; 116 } 117 118 if ($function eq "if") { 119 push @ifstack, $self->$function(@_, [@args]); 120 } elsif ($function eq "else" and @ifstack > 1) { 121 $ifstack[-1] = not $ifstack[-1]; 122 } elsif ($function eq "endif" and @ifstack > 1) { 123 pop @ifstack; 124 } elsif ($ifstack[-1]) { 125 if ($self->can($function)) { 126 print $self->$function(@_, {@args}); 127 } 128 } 129 } 130 131 if ($ifstack[-1]) { 132 print substr($line, (defined pos $line) ? pos $line : 0), "\n"; 133 } 134 } 135 } 136 137 # cook_args(STRING) - parses a string of the form ARG1="FOO" ARG2="BAR". Returns 138 # a list which pairs into key/values and fits nicely in {}s. 139 # 140 sub cook_args($) { 141 my ($raw_args) = @_; 142 my @args = (); 143 144 # Boy I love m//g in scalar context! Go read the camel book, heathen. 145 # First, get the whole token with the quotes on both ends... 146 while ($raw_args =~ m/\G\s*(\w*)="((?:[^"\\]|\\.)*)"/g) { 147 my ($key, $value) = ($1, $2); 148 # ... then, rip out all the protecty backspaces 149 $value =~ s/\\(.)/$1/g; 150 push @args, $key => $value; 151 } 152 153 return @args; 154 } 155 156 # This is different. It probably shouldn't print anything (except in debugging cases) 157 # and it should return a boolean, not a string. &if is called in a nonstandard way 158 # by &template, with $args as an arrayref instead of a hashref. this is a hack! yay! 159 160 # OK, this is a pluggin architecture. it iterates through attributes of the "if" tag, 161 # and for each predicate $p, it calls &if_$p in an object-oriented way, continuing the 162 # grand templating theme of an object-oriented pluggable architecture using ->can($). 163 sub if { 164 my ($self, $args) = @_[0,-1]; 165 # A single if "or"s it's components. Nesting produces "and". 166 167 my @args = @$args; # Hahahahaha, get it?! 168 169 if (@args % 2 != 0) { 170 # flip out and kill people, but do not commit seppuku 171 print '<!--&if recieved an uneven number of arguments. This shouldn\'t happen, but I\'ll let it slide.-->\n'; 172 } 173 174 while (@args > 1) { 175 my ($key, $value) = (shift @args, shift @args); 176 177 # a non-existent &if_$key is the same as a false result, but we're ORing, so it's OK 178 my $sub = "if_$key"; # perl doesn't like it when you try to construct a string right in a method invocation 179 if ($self->can("if_$key") and $self->$sub("$value")) { 180 return 1; 181 } 182 } 183 184 return 0; 185 } 186 187 ################################################################################ 188 # Macros used by content generators to render common idioms 189 ################################################################################ 190 191 # pathMacro(HASHREF, LIST) - helper macro for <!--#path--> escape: the hash 192 # reference contains the "style", "image", and "text" arguments to the escape. 193 # The LIST consists of ordered key-value pairs of the form: 194 # 195 # "Page Name" => URL 196 # 197 # If the page should not have a link associated with it, the URL should be left 198 # empty. Authentication data is added to the URL so you don't have to. A fully- 199 # formed path line is returned, suitable for returning by a function 200 # implementing the #path escape. 201 # 202 sub pathMacro { 203 my $self = shift; 204 my %args = %{ shift() }; 205 my @path = @_; 206 my $sep; 207 if ($args{style} eq "image") { 208 $sep = CGI::img({-src=>$args{image}, -alt=>$args{text}}); 209 } else { 210 $sep = $args{text}; 211 } 212 my $auth = $self->url_authen_args; 213 my @result; 214 while (@path) { 215 my $name = shift @path; 216 my $url = shift @path; 217 push @result, $url 218 ? CGI::a({-href=>"$url?$auth"}, $name) 219 : $name; 220 } 221 return join($sep, @result), "\n"; 222 } 223 224 sub siblingsMacro { 225 my $self = shift; 226 my @siblings = @_; 227 my $sep = CGI::br(); 228 my $auth = $self->url_authen_args; 229 my @result; 230 while (@siblings) { 231 my $name = shift @siblings; 232 my $url = shift @siblings; 233 push @result, $url 234 ? CGI::a({-href=>"$url?$auth"}, $name) 235 : $name; 236 } 237 return join($sep, @result), "\n"; 238 } 239 240 sub navMacro { 241 my $self = shift; 242 my %args = %{ shift() }; 243 my $tail = shift; 244 my @links = @_; 245 my $auth = $self->url_authen_args; 246 my @result; 247 while (@links) { 248 my $name = shift @links; 249 my $url = shift @links; 250 push @result, $url 251 ? CGI::a({-href=>"$url?$auth$tail"}, $name) 252 : $name; 253 } 254 return join($args{separator}, @result), "\n"; 255 } 256 257 # hidden_fields(LIST) - return hidden <INPUT> tags for each field mentioned in 258 # LIST (or all fields if list is empty), taking data from the current request. 259 # 260 sub hidden_fields($;@) { 261 my $self = shift; 262 my $r = $self->{r}; 263 my @fields = @_; 264 @fields or @fields = $r->param; 265 my $courseEnvironment = $self->{courseEnvironment}; 266 my $html = ""; 267 268 foreach my $param (@fields) { 269 my $value = $r->param($param); 270 $html .= CGI::input({-type=>"hidden",-name=>"$param",-value=>"$value"}); 271 } 272 return $html; 273 } 274 275 # hidden_authen_fields() - use hidden_fields to return hidden <INPUT> tags for 276 # request fields used in authentication. 277 # 278 sub hidden_authen_fields($) { 279 my $self = shift; 280 return $self->hidden_fields("user","effectiveUser","key"); 281 } 282 283 # url_args(LIST) - return a URL query string (without the leading `?') 284 # containing values for each field mentioned in LIST, or all fields if list is 285 # empty. Data is taken from the current request. 286 # 287 sub url_args($;@) { 288 my $self = shift; 289 my $r = $self->{r}; 290 my @fields = @_; 291 @fields or @fields = $r->param; 292 my $courseEnvironment = $self->{courseEnvironment}; 293 294 my @pairs; 295 foreach my $param (@fields) { 296 my $value = $r->param($param) || ""; 297 push @pairs, uri_escape($param) . "=" . uri_escape($value); 298 } 299 300 return join("&", @pairs); 301 } 302 303 # url_authen_args() - use url_args to return a URL query string for request 304 # fields used in authentication. 305 # 306 sub url_authen_args($) { 307 my $self = shift; 308 my $r = $self->{r}; 309 return $self->url_args("user","effectiveUser","key"); 310 } 311 312 # print_form_data(BEGIN, MIDDLE, END, OMIT) - return a string containing request 313 # fields not matched by OMIT, placing BEGIN before each field name, MIDDLE 314 # between each field and its value, and END after each value. Values are taken 315 # from the current request. OMIT is a quoted reguar expression. 316 # 317 sub print_form_data { 318 my ($self, $begin, $middle, $end, $qr_omit) = @_; 319 my $return_string = ""; 320 my $r=$self->{r}; 321 my @form_data = $r->param; 322 foreach my $name (@form_data) { 323 next if ($qr_omit and $name =~ /$qr_omit/); 324 my @values = $r->param($name); 325 foreach my $variable (qw(begin name middle value end)) { 326 no strict 'refs'; 327 ${$variable} = "" unless defined ${$variable}; 328 } 329 foreach my $value (@values) { 330 $return_string .= "$begin$name$middle$value$end"; 331 } 332 } 333 return $return_string; 334 } 335 336 sub errorOutput($$$) { 337 my ($self, $error, $details) = @_; 338 return 339 CGI::h2("Software Error"), 340 CGI::p(<<EOF), 341 WeBWorK has encountered a software error while attempting to process this problem. 342 It is likely that there is an error in the problem itself. 343 If you are a student, contact your professor to have the error corrected. 344 If you are a professor, please consut the error output below for more informaiton. 345 EOF 346 CGI::h3("Error messages"), CGI::blockquote(CGI::pre($error)), 347 CGI::h3("Error context"), CGI::blockquote(CGI::pre($details)); 348 } 349 350 sub warningOutput($$) { 351 my ($self, $warnings) = @_; 352 353 return 354 CGI::h2("Software Warnings"), 355 CGI::p(<<EOF), 356 WeBWorK has encountered warnings while attempting to process this problem. 357 It is likely that this indicates an error or ambiguity in the problem itself. 358 If you are a student, contact your professor to have the problem corrected. 359 If you are a professor, please consut the error output below for more informaiton. 360 EOF 361 CGI::h3("Warning messages"), 362 CGI::blockquote(CGI::pre($warnings)), 363 ; 364 } 365 366 ################################################################################ 367 # Generic versions of template escapes 368 ################################################################################ 369 370 # Reminder: here are the template functions currently defined: 371 # 372 # head 373 # path 374 # style = text|image 375 # image = URL of image 376 # text = text separator 377 # loginstatus 378 # links 379 # siblings 380 # nav 381 # style = text|image 382 # imageprefix = prefix to image URL 383 # imagesuffix = suffix to image URL 384 # separator = HTML to place in between links 385 # title 386 # body 387 388 sub header { 389 my $self = shift; 390 my $r = $self->{r}; 391 $r->content_type('text/html'); 392 $r->send_http_header(); 393 } 394 395 sub loginstatus { 396 my $self = shift; 397 my $r = $self->{r}; 398 my $user = $r->param("user"); 399 my $eUser = $r->param("effectiveUser"); 400 my $key = $r->param("key"); 401 return "" unless $key; 402 my $exitURL = $r->uri() . "?user=$user&key=$key"; 403 print CGI::small("Logged in as:", CGI::br(), "$user"); 404 if ($user ne $eUser) { 405 print CGI::br(), CGI::font({-color=>'red'}, 406 CGI::small("Acting as:", CGI::br(), "$eUser") 407 ), 408 CGI::br(), CGI::a({-href=>$exitURL}, 409 CGI::small("Stop Acting") 410 ); 411 } 412 return ""; 413 } 414 415 # *** drunk code. rewrite. 416 # also, this should be structured s.t. subclasses can add items to the links 417 # area, i.e. "stacking" 418 sub links { 419 my $self = shift; 420 my $ce = $self->{courseEnvironment}; 421 my $userName = $self->{r}->param("user"); 422 my $courseName = $ce->{courseName}; 423 my $root = $ce->{webworkURLs}->{root}; 424 my $permLevel = WeBWorK::DB::Auth->new($ce)->getPermissions($userName); 425 my $key = WeBWorK::DB::Auth->new($ce)->getKey($userName); 426 return "" unless defined $key; 427 428 # URLs to parts of the system 429 my $probSets = "$root/$courseName/?" . $self->url_authen_args(); 430 my $prefs = "$root/$courseName/options/?" . $self->url_authen_args(); 431 my $prof = "$root/$courseName/prof/?" . $self->url_authen_args(); 432 my $help = "$ce->{webworkURLs}->{docs}?" . $self->url_authen_args(); 433 my $logout = "$root/$courseName/logout/?" . $self->url_authen_args(); 434 435 return 436 CGI::a({-href=>$probSets}, "Problem Sets"), CGI::br(), 437 CGI::a({-href=>$prefs}, "User Options"), CGI::br(), 438 ($permLevel > 0 439 ? CGI::a({-href=>$prof}, "Professor") . CGI::br() 440 : ""), 441 CGI::a({-href=>$help}, "Help"), CGI::br(), 442 CGI::a({-href=>$logout}, "Log Out"), CGI::br(), 443 ; 444 } 445 446 # &if_can will return 1 if the current object->can("do $_[1]") 447 sub if_can ($$) { 448 my ($self, $arg) = (@_); 449 450 if ($self->can("$arg")) { 451 return 1; 452 } else { 453 return 0; 454 } 455 } 456 457 1; 458 459 __END__ 460 461 =head1 AUTHOR 462 463 Written by Dennis Lambe Jr., malsyned (at) math.rochester.edu 464 and Sam Hathaway, sh002i (at) math.rochester.edu. 465 466 =cut
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