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dangerousMacros.pl --- located in the courseScripts directory
loadMacros(macrofile1,macrofile2,...)
insertGraph(graphObject);
returns a path to the file containing the graph image.
tth(texString)
returns an HTML version of the tex code passed to it.
alias(pathToFile);
returns URL which links to that file
dangerousMacros.pl contains macros with potentially dangerous commands
such as require and eval. They can reference disk files for reading and
writing and can create links. It may be necessary to modify certain addresses
in this file to make the scripts run properly in different environments.
dangerousMacros.pl is loaded and reinitialized
every time a new problem is rendered.
Most modules are loaded by dangerousMacros.pl
The modules must be loaded using require (not use) since the courseScriptsDirectory
is
defined at run time.
The following considerations come into play.
* One needs to limit the access to modules for safety -- hence only
modules in the F<courseScriptsDirectory> can be loaded.
* Loading them in dangerousMacros.pl is wasteful, since the modules
would need to be reloaded everytime a new safe compartment is created.
(I believe that using require takes care of this.)
* Loading GD within a safeCompartment creates infinite recurrsion in AUTOLOAD
(probably a bug)
hence this module is loaded by translate.pl and then shared with
the safe compartment.
* Other modules loaded by translate.pl are C<Exporter> and C<DynaLoader.
* PGrandom is loaded by F<PG.pl> , since it is needed there.
The module name spaces loaded in dangerousMacros are:
PGrandom (if not previously loaded)
WWPlot
Fun
Label
Circle
in addition the subroutine &evaluate_units is shared from the module Units.
loadMacros(macrofile1,macrofile2,...)
loadMacros takes a list of file names and evaluates the contents of each file. This
is used to load macros
which define and augment the PG language. The macro files are searched for in the
directories specified by
($macrosPath), which by default is the course macros directory followed by WeBWorK's
pg/macros directory.
The latter is where the default behaviour of the PG language is defined. The default
path is set in
the (global.conf) file.
An individual course can modify the PG language, for that course only, by
duplicating one of the macro files in the courseScripts directory and placing this
file in the macro directory for the course. The new file in the course
macro directory will now be used instead of the file in the courseScripts directory.
The new file in the course macro directory can by modified by adding macros or modifying
existing macros.
Modifying macros is for users with some experience.
Modifying existing macros might break other standard macros or problems which depend
on the
unmodified behavior of these macors so do this with great caution.
In addition problems which use new macros defined in these files or which depend
on the
modified behavior of existing macros will not work in other courses unless the macros
are also
transferred to the new course. It helps to document the problems by indicating
any special macros
which the problems require.
There is no facility for modifying or overloading a single macro. The entire file
containing the macro
must be overloaded.
Modifications to files in the course macros directory affect only that course,
they will not interfere with the normal behavior of WeBWorK in other courses.
$filePath = insertGraph(graphObject);
returns a path to the file containing the graph image.
insertGraph(graphObject) writes a gif file to the html/tmp/gif directory of the current
course.
The file name
is obtained from the graphObject. Warnings are issued if errors occur while writing
to
the file.
The permissions and ownership of the file are controlled by $main::tmp_file_permission
and $main::numericalGroupID.
Returns: A string containing the full path to the temporary file containing the
GIF image.
InsertGraph draws the object $graph, stores it in "${tempDirectory}gif/$gifName.gif
(or .png)" where
the $imageName is obtained from the graph object. ConvertPath and surePathToTmpFile
are used to insure
that the correct directory separators are used for the platform and that the necessary
directories
are created if they are not already present.
The directory address to the file is the result. This is most often used in the
construct
TEXT(alias(insertGraph($graph)) );
where alias converts the directory address to a URL when serving HTML pages and insures
that
an eps file is generated when creating TeX code for downloading.
tth(texString)
returns an HTML version of the tex code passed to it.
This macro sends the texString to the filter program tth created by Ian Hutchinson.
The tth program was created by Ian Hutchinson and is freely available
for non-commerical purposes at the tth main site: http://hutchinson.belmont.ma.us/tth/.
The purpose of tth is to translate text in the TeX or Latex markup language into
HTML markup as best as possible. Some symbols, such as square root symbols are
not
translated completely. Macintosh users must use the "MacRoman" encoding (available
in 4.0 and
higher browsers) in order to view the symbols correctly. WeBWorK attempts to force
Macintosh
browsers to use this encoding when such a browser is detected.
The contents of the file tthPreamble.tex in the courses template directory are prepended
to each string. This allows one to define TeX macros which can be used in every problem.
Currently there is no default tthPreamble.tex file, so if the file is not present
in the
course template directory no TeX macro definitions are prepended. tth already understands
most
Latex commands, but will not, in general know AMS-Latex commands. Additional information
on tth is available at the tth main site.
This macro contains code which is system dependent and may need to be modified
to run on different systems.
The link to tth for non-commerical is
http://hutchinson.belmont.ma.us/tth/.
Binaries for many operating systems are available as well as the source code. Links
describing how to obtain tth for commerical use are also available on this page.
math2img(texString) - returns an IMG tag pointing to an image version of the supplied
TeX
alias(pathToFile);
returns A string describing the URL which links to GIF or html file
(in HTML and Latex2HTML modes).
or a path to the appropriate eps version of a GIF file
(TeX Mode)
alias allows you to refer to auxiliary files which are in a directory along with
the problem definition. In addition alias creates an eps copy of GIF files when
downloading hard copy (TeX mode).
As a rule auxiliary files that are used by
a number of problems in a course should be placed in html/gif or html
or in a subdirectory of the html directory,
while auxiliary files which are used in only one problem should be placed in
the same directory as the problem in order to make the problem more portable.
- Files in the html subdirectory
-
When not in TeX mode:
-
If the file lies under the html subdirectory, then the approriate URL for the file
is created.
Since the html subdirectory is already accessible to the webserver no other changes
need to be made.
The file path for this type of file should be the complete file path. The path should
start with the prefix defined in $Global:htmlDirectory.
-
When in TeX mode:
-
GIF files will be translated into an eps file (using system dependent code)
and placed in the directory tmp/eps. The full path to this file is returned
for use by TeX in producing the hard copy. (This should work even in a chrooted
environment.) in producing the hard copy. (This should work even in a chrooted
environment.)
-
The conversion is done by a system dependent script
called gif2eps which should be in the scripts directory
-
The URL's for the other files are produced as in non-tex mode
but will of course not be active.
- Files in the tmp subdirectory
-
When not in TeX mode:
-
If the file lies under the tmp subdirectory, then the approriate URL for the file
is created.
Since the tmp subdirectory is already accessible to the webserver no other changes
need to be made.
The file path for this type of file should be the complete file path. The path should
start with the prefix defined in $Global:tempDirectory.
-
When in TeX mode:
-
GIF files will be translated into an eps file (using system dependent code)
and placed in the directory tmp/eps. The full path to this file is returned
for use by TeX in producing the hard copy. (This should work even in a chrooted
environment.)
-
The conversion is done by a system dependent script
called gif2eps which should be in the scripts directory
-
The URL's for the other files are produced as in non-tex mode
but will of course not be active.
- Files in the course template subdirectory:
-
When not in TeX mode:
-
If the file lies under the course templates subdirectory,
it is assumed to lie in subdirectory rooted in the directory
containing the problem template file.
An alias is created under the html/tmp/gif or
html/tmp/html directory and linked to the original file.
The file path for this type of file is a relative
path rooted at the directory containing the problem template file.
-
When in TeX mode:
-
GIF files will be translated into an eps file (using system dependent code)
and placed in the directory html/tmp/eps. The full path to this file is returned
for use by TeX in producing the hard copy. (This should work even in a chrooted
environment.)
-
The conversion is done by a system dependent script
called gif2eps which should be in the scripts directory
-
The URL's for the other files are produced as in non-tex mode
but will of course not be active.
File path = /ww/webwork/pg/macros/dangerousMacros.pl
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