Ability to use Mathjax for TeX rendering

1 files changed, 138 insertions, 131 deletions

diff --git a/edit_algebra_form.php b/edit_algebra_form.php
index 033cb84..2afcd0a 100644
--- a/edit_algebra_form.php
+++ b/edit_algebra_form.php
@@ -1,12 +1,23 @@
 <?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
 /**
- * Defines the editing form for the algebra question type.
- *
- * @copyright &copy; 2008 Roger Moore
- * @author Roger Moore <rwmoore@ualberta.ca>
- * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
- * @package questionbank
- * @subpackage questiontypes
+ * @package    qtype_algebra
+ * @copyright  Roger Moore <rwmoore@ualberta.ca>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
 require_once($CFG->dirroot . '/question/type/edit_question_form.php');
@@ -14,12 +25,12 @@ require_once($CFG->dirroot . '/question/type/algebra/questiontype.php');
 require_once($CFG->dirroot . '/question/type/algebra/parser.php');
 
 // Override the default number of answers and the number to add to avoid clutter.
-// Algebra questions will likely not have huge number of different answers...
+// Algebra questions will likely not have huge number of different answers.
 define("SYMB_QUESTION_NUMANS_START", 2);
 define("SYMB_QUESTION_NUMANS_ADD", 1);
 
-// Override the default number of answers and the number to add to avoid clutter.
-// algebra questions will likely not have huge number of different answers...
+// Override the default number of variables and the number to add to avoid clutter.
+// Algebra questions will likely not have huge number of different variables.
 define("SYMB_QUESTION_NUMVAR_START", 2);
 define("SYMB_QUESTION_NUMVAR_ADD", 1);
 
@@ -34,98 +45,97 @@ class qtype_algebra_edit_form extends question_edit_form {
      */
     protected function definition_inner($mform) {
         global $CFG;
-        // Add the select control which will select the comparison type to use
-        $mform->addElement('select', 'compareby', get_string('compareby','qtype_algebra'),
+        // Add the select control which will select the comparison type to use.
+        $mform->addElement('select', 'compareby', get_string('compareby', 'qtype_algebra'),
                            array( "sage"  => get_string('comparesage', 'qtype_algebra'),
                                   "eval"  => get_string('compareeval', 'qtype_algebra'),
-                                  "equiv" => get_string('compareequiv','qtype_algebra')
+                                  "equiv" => get_string('compareequiv', 'qtype_algebra')
                                  ));
         $mform->addHelpButton('compareby', 'compareby', 'qtype_algebra');
-        $mform->setDefault('compareby',$CFG->qtype_algebra_method);
+        $mform->setDefault('compareby', $CFG->qtype_algebra_method);
 
-        // Add the control to select the number of checks to perform
+        // Add the control to select the number of checks to perform.
         // First create an array with all the allowed values. We will then use this array
         // with the array_combine function to create a single array where the keys are the
-        // same as the array values
+        // same as the array values.
         $chk_array=array(  '1',   '2',   '3',   '5',   '7',
                           '10',  '20',  '30',  '50',  '70',
                          '100', '200', '300', '500', '700', '1000');
-        // Add the select element using the array_combine method discussed above
-        $mform->addElement('select', 'nchecks', get_string('nchecks','qtype_algebra'),
-                            array_combine($chk_array,$chk_array));
+        // Add the select element using the array_combine method discussed above.
+        $mform->addElement('select', 'nchecks', get_string('nchecks', 'qtype_algebra'),
+                            array_combine($chk_array, $chk_array));
         $mform->addHelpButton('nchecks', 'nchecks', 'qtype_algebra');
-        // Set the default number of checks to perform
-        $mform->setDefault('nchecks','10');
+        // Set the default number of checks to perform.
+        $mform->setDefault('nchecks', '10');
 
-
-        // Add the box to set the tolerance to use when performing evaluation checks
-        $mform->addElement('text', 'tolerance', get_string('tolerance','qtype_algebra'));
+        // Add the box to set the tolerance to use when performing evaluation checks.
+        $mform->addElement('text', 'tolerance', get_string('tolerance', 'qtype_algebra'));
         $mform->addHelpButton('tolerance', 'tolerance', 'qtype_algebra');
         $mform->setType('tolerance', PARAM_NUMBER);
-        $mform->setDefault('tolerance','0.001');
+        $mform->setDefault('tolerance', '0.001');
 
-        // Add an entry for the answer box prefix
-        $mform->addElement('text', 'answerprefix', get_string('answerprefix','qtype_algebra'),array('size'=>55));
+        // Add an entry for the answer box prefix.
+        $mform->addElement('text', 'answerprefix', get_string('answerprefix', 'qtype_algebra'), array('size'=>55));
         $mform->addHelpButton('answerprefix', 'answerprefix', 'qtype_algebra');
         $mform->setType('answerprefix', PARAM_RAW);
 
-        // Add an entry for a disallowed expression
-        $mform->addElement('text', 'disallow', get_string('disallow','qtype_algebra'),array('size'=>55));
+        // Add an entry for a disallowed expression.
+        $mform->addElement('text', 'disallow', get_string('disallow', 'qtype_algebra'), array('size'=>55));
         $mform->addHelpButton('disallow', 'disallow', 'qtype_algebra');
         $mform->setType('disallow', PARAM_RAW);
 
-        // Create an array which will store the function checkboxes
+        // Create an array which will store the function checkboxes.
         $func_group=array();
-        // Create an array to add spacers between the boxes
+        // Create an array to add spacers between the boxes.
         $spacers=array('<br>');
-        // Add the initial all functions box to the list of check boxes
-        $func_group[] =& $mform->createElement('checkbox','all','',get_string('allfunctions','qtype_algebra'));
-        // Create a checkbox element for each function understood by the parser
-        for($i=0;$i<count(qtype_algebra_parser::$functions);$i++) {
+        // Add the initial all functions box to the list of check boxes.
+        $func_group[] =& $mform->createElement('checkbox', 'all', '', get_string('allfunctions', 'qtype_algebra'));
+        // Create a checkbox element for each function understood by the parser.
+        for ($i=0; $i<count(qtype_algebra_parser::$functions); $i++) {
             $func=qtype_algebra_parser::$functions[$i];
-            $func_group[] =& $mform->createElement('checkbox',$func,'',$func);
-            if(($i % 6) == 5) {
+            $func_group[] =& $mform->createElement('checkbox', $func, '', $func);
+            if (($i % 6) == 5) {
                 $spacers[]='<br>';
             } else {
-                $spacers[]=str_repeat('&nbsp;',8-strlen($func));
+                $spacers[]=str_repeat('&nbsp;', 8-strlen($func));
             }
         }
-        // Create and add the group of function controls to the form
-        $mform->addGroup($func_group,'allowedfuncs',get_string('allowedfuncs','qtype_algebra'),$spacers,true);
+        // Create and add the group of function controls to the form.
+        $mform->addGroup($func_group, 'allowedfuncs', get_string('allowedfuncs', 'qtype_algebra'), $spacers, true);
         $mform->addHelpButton('allowedfuncs', 'allowedfuncs', 'qtype_algebra');
-        $mform->disabledIf('allowedfuncs','allowedfuncs[all]','checked');
-        $mform->setDefault('allowedfuncs[all]','checked');
+        $mform->disabledif ('allowedfuncs', 'allowedfuncs[all]', 'checked');
+        $mform->setDefault('allowedfuncs[all]', 'checked');
 
         $mform->addElement('static', 'variablesinstruct',
                 get_string('variables', 'qtype_algebra'),
                 get_string('filloutonevariable', 'qtype_algebra'));
         $mform->closeHeaderBefore('variablesinstruct');
-        // Create the array for the list of variables used in the question
+        // Create the array for the list of variables used in the question.
         $repeated=array();
-        // Create the array for the list of repeated options used by the variable subforms
+        // Create the array for the list of repeated options used by the variable subforms.
         $repeatedoptions = array();
 
-        // Add the form elements to enter the variables
-        $repeated[] =& $mform->createElement('header','variablehdr',get_string('variableno','qtype_algebra','{no}'));
-        //$repeatedoptions['variablehdr']['helpbutton'] = array('variable',get_string('variable','qtype_algebra'),
+        // Add the form elements to enter the variables.
+        $repeated[] =& $mform->createElement('header', 'variablehdr', get_string('variableno', 'qtype_algebra', '{no}'));
+        // $repeatedoptions['variablehdr']['helpbutton'] = array('variable', get_string('variable', 'qtype_algebra'),
         //                                                      'qtype_algebra');
-        $repeated[] =& $mform->createElement('text','variable',get_string('variablename','qtype_algebra'),array('size'=>20));
+        $repeated[] =& $mform->createElement('text', 'variable', get_string('variablename', 'qtype_algebra'), array('size'=>20));
         $mform->setType('variable', PARAM_RAW);
-        $repeated[] =& $mform->createElement('text','varmin',get_string('varmin','qtype_algebra'),array('size'=>20));
+        $repeated[] =& $mform->createElement('text', 'varmin', get_string('varmin', 'qtype_algebra'), array('size'=>20));
         $mform->setType('varmin', PARAM_RAW);
         $repeatedoptions['varmin']['default'] = '';
-        $repeated[] =& $mform->createElement('text','varmax',get_string('varmax','qtype_algebra'),array('size'=>20));
+        $repeated[] =& $mform->createElement('text', 'varmax', get_string('varmax', 'qtype_algebra'), array('size'=>20));
         $mform->setType('varmax', PARAM_RAW);
         $repeatedoptions['varmax']['default'] = '';
 
-        // Get the current number of variables defined, if any
+        // Get the current number of variables defined, if any.
         if (isset($this->question->options)) {
             $countvars = count($this->question->options->variables);
         } else {
             $countvars = 0;
         }
-        // Come up with the number of variable entries to add to the form at the start
-        if ($this->question->formoptions->repeatelements){
+        // Come up with the number of variable entries to add to the form at the start.
+        if ($this->question->formoptions->repeatelements) {
             $repeatsatstart = (SYMB_QUESTION_NUMVAR_START > ($countvars + SYMB_QUESTION_NUMVAR_ADD))?
             SYMB_QUESTION_NUMVAR_START : ($countvars + SYMB_QUESTION_NUMVAR_ADD);
         } else {
@@ -170,24 +180,24 @@ class qtype_algebra_edit_form extends question_edit_form {
      *
      * @param $question the question object from the database being used to fill the form
      */
-    function set_data($question) {
+    public function set_data($question) {
         // Check to see if there are any existing question options, if not then just call
-        // the base class set data method and exit
+        // the base class set data method and exit.
         if (!isset($question->options)) {
             return parent::set_data($question);
         }
 
-        // Now we do exactly the same for the variables...
+        // Now we do exactly the same for the variables.
         $vars = $question->options->variables;
         // If we found any variables then loop over them using a numerical key to provide an index
-        // to the arrays we need to access in the form
+        // to the arrays we need to access in the form.
         if (count($vars)) {
             $key = 0;
             foreach ($vars as $var) {
-                // For every variable set the default values
+                // For every variable set the default values.
                 $default_values['variable['.$key.']'] = $var->name;
-                // Only set the min and max defaults if this variable has a range
-                if($var->min!='') {
+                // Only set the min and max defaults if this variable has a range.
+                if ($var->min!='') {
                     $default_values['varmin['.$key.']'] = $var->min;
                     $default_values['varmax['.$key.']'] = $var->max;
                 }
@@ -195,32 +205,31 @@ class qtype_algebra_edit_form extends question_edit_form {
             }
         }
 
-        // Add the default values for the allowed functions controls
-        // First check to see if there are any allowed functions defined
-        if(count($question->options->allowedfuncs)>0) {
-            // Clear the 'all functions' flag since functions are restricted
+        // Add the default values for the allowed functions controls.
+        // First check to see if there are any allowed functions defined.
+        if (count($question->options->allowedfuncs)>0) {
+            // Clear the 'all functions' flag since functions are restricted.
             $default_values['allowedfuncs[all]']=0;
-            // Loop over all the functions which the parser understands
-            foreach(qtype_algebra_parser::$functions as $func) {
+            // Loop over all the functions which the parser understands.
+            foreach (qtype_algebra_parser::$functions as $func) {
                 // For each function see if the function is in the allowed function
-                // list and if so set the check box otherwise remove the check box
-                if(in_array($func,$question->options->allowedfuncs)) {
+                // list and if so set the check box otherwise remove the check box.
+                if (in_array($func, $question->options->allowedfuncs)) {
                     $default_values['allowedfuncs['.$func.']']=1;
                 } else {
                     $default_values['allowedfuncs['.$func.']']=0;
                 }
             }
-        }
-        // There are no allowed functions defined so all functions are allowed
-        else {
+        } else {
+            // There are no allowed functions defined so all functions are allowed.
             $default_values['allowedfuncs[all]']=1;
         }
 
         // Add the default values to the question object in a form which the parent
-        // set data method will be able to use to find the default values
+        // set data method will be able to use to find the default values.
         $question = (object)((array)$question + $default_values);
 
-        // Finally call the parent set data method to handle everything else
+        // Finally call the parent set data method to handle everything else.
         parent::set_data($question);
     }
 
@@ -234,102 +243,100 @@ class qtype_algebra_edit_form extends question_edit_form {
      * @param $files some files - I don't know what this is for! - files defined in the form??
      */
     public function validation($data, $files) {
-        // Call the base class validation method and keep any errors it generates
+        // Call the base class validation method and keep any errors it generates.
         $errors = parent::validation($data, $files);
 
-        // Regular expression string to match a number
+        // Regular expression string to match a number.
         $renumber='/([+-]*(([0-9]+\.[0-9]*)|([0-9]+)|(\.[0-9]+))|'.
             '(([0-9]+\.[0-9]*)|([0-9]+)|(\.[0-9]+))E([-+]?\d+))/A';
 
         // Perform sanity checks on the variables.
         $vars = $data['variable'];
-        // Create an array of defined variables
+        // Create an array of defined variables.
         $varlist=array();
         foreach ($vars as $key => $var) {
             $trimvar = trim($var);
             $trimmin = trim($data['varmin'][$key]);
             $trimmax = trim($data['varmax'][$key]);
-            // Check that there is a valid variable name otherwise skip
+            // Check that there is a valid variable name otherwise skip.
             if ($trimvar == '') {
                 continue;
             }
-            // Check that this variable does not have the same name as a function
-            if(in_array($trimvar,qtype_algebra_parser::$functions) or in_array($trimvar,qtype_algebra_parser::$specials)) {
-                $errors['variable['.$key.']'] = get_string('illegalvarname','qtype_algebra',$trimvar);
+            // Check that this variable does not have the same name as a function.
+            if (in_array($trimvar, qtype_algebra_parser::$functions) or in_array($trimvar, qtype_algebra_parser::$specials)) {
+                $errors['variable['.$key.']'] = get_string('illegalvarname', 'qtype_algebra', $trimvar);
             }
-            // Check that this variable has not been defined before
-            if(in_array($trimvar,$varlist)) {
-                $errors['variable['.$key.']'] = get_string('duplicatevar','qtype_algebra');
+            // Check that this variable has not been defined before.
+            if (in_array($trimvar, $varlist)) {
+                $errors['variable['.$key.']'] = get_string('duplicatevar', 'qtype_algebra');
             } else {
-                // Add the variable to the list of defined variables
+                // Add the variable to the list of defined variables.
                 $varlist[]=$trimvar;
             }
             // If the comparison algorithm selected is evaluate then ensure that each variable
             // has a valid minimum and maximum defined. For the other types of comparison we can
-            // ignore the range
-            if($data['compareby']=='eval') {
-                // Check that a minimum has been defined
+            // ignore the range.
+            if ($data['compareby']=='eval') {
+                // Check that a minimum has been defined.
                 if ($trimmin == '') {
-                    $errors['varmin['.$key.']'] = get_string('novarmin','qtype_algebra');
-                }
-                // If there is one check that it is a number
-                else if(!preg_match($renumber,$trimmin)) {
-                    $errors['varmin['.$key.']'] = get_string('notanumber','qtype_algebra');
+                    $errors['varmin['.$key.']'] = get_string('novarmin', 'qtype_algebra');
+                } else if (!preg_match($renumber, $trimmin)) {
+                    // If there is one check that it's a number.
+                    $errors['varmin['.$key.']'] = get_string('notanumber', 'qtype_algebra');
                 }
                 if ($trimmax == '') {
-                    $errors['varmax['.$key.']'] = get_string('novarmax','qtype_algebra');
-                }
-                // If there is one check that it is a number
-                else if(!preg_match($renumber,$trimmax)) {
-                    $errors['varmax['.$key.']'] = get_string('notanumber','qtype_algebra');
+                    $errors['varmax['.$key.']'] = get_string('novarmax', 'qtype_algebra');
+                } else if (!preg_match($renumber, $trimmax)) {
+                    // If there is one check that it is a number.
+                    $errors['varmax['.$key.']'] = get_string('notanumber', 'qtype_algebra');
                 }
                 // Check that the minimum is less that the maximum!
                 if ((float)$trimmin > (float)$trimmax) {
-                    $errors['varmin['.$key.']'] = get_string('varmingtmax','qtype_algebra');
+                    $errors['varmin['.$key.']'] = get_string('varmingtmax', 'qtype_algebra');
                 }
-            } // end check for eval type
-        }     // end loop over variables
-        // Check that at least one variable is defined
+            } // End check for eval type.
+        }     // End loop over variables.
+        // Check that at least one variable is defined.
         if (count($varlist)==0) {
             $errors['variable[0]'] = get_string('notenoughvars', 'qtype_algebra');
         }
 
-        // Now perform the sanity checks on the answers
-        // Create a parser which we will use to check that the answers are understandable
+        // Now perform the sanity checks on the answers.
+        // Create a parser which we will use to check that the answers are understandable.
         $p = new qtype_algebra_parser;
         $answers = $data['answer'];
         $answercount = 0;
         $maxgrade = false;
-        // Create an empty array to store the used variables
+        // Create an empty array to store the used variables.
         $ansvars=array();
-        // Create an empty array to store the used functions
+        // Create an empty array to store the used functions.
         $ansfuncs=array();
-        // Loop over all the answers in the form
+        // Loop over all the answers in the form.
         foreach ($answers as $key => $answer) {
             // Try to parse the answer string using the parser. If this fails it will
             // throw an exception which we catch to generate the associated error string
-            // for the expression
+            // for the expression.
             try {
                 $expr=$p->parse($answer);
                 // Add any new variables to the list we are keeping. First we get the list
                 // of variables in this answer. Then we get the array of variables which are
                 // in this answer that are not in any previous answer (using array_diff).
-                // Finally we merge this difference array with the list of all variables so far
+                // Finally we merge this difference array with the list of all variables so far.
                 $tmpvars=$expr->get_variables();
-                $ansvars=array_merge($ansvars,array_diff($tmpvars,$ansvars));
-                // Check that all the variables in this answer have been declared
+                $ansvars=array_merge($ansvars, array_diff($tmpvars, $ansvars));
+                // Check that all the variables in this answer have been declared.
                 // Do this by looking for a non-empty array to be returned from the array_diff
-                // between the list of all declared variables and the variables in this answer
-                if($d=array_diff($tmpvars,$varlist)) {
-                    $errors['answer['.$key.']'] = get_string('undefinedvar','qtype_algebra',"'".implode("', '",$d)."'");
+                // between the list of all declared variables and the variables in this answer.
+                if ($d=array_diff($tmpvars, $varlist)) {
+                    $errors['answer['.$key.']'] = get_string('undefinedvar', 'qtype_algebra', "'".implode("', '", $d)."'");
                 }
-                // Do the same for functions which we did for variables
-                $ansfuncs=array_merge($ansfuncs,array_diff($expr->get_functions(),$ansfuncs));
-                // Check that this is not an empty answer
-                if (!is_a($expr,"qtype_algebra_parser_nullterm")) {
-                    // Increase the number of answers
+                // Do the same for functions which we did for variables.
+                $ansfuncs=array_merge($ansfuncs, array_diff($expr->get_functions(), $ansfuncs));
+                // Check that this is not an empty answer.
+                if (!is_a($expr, "qtype_algebra_parser_nullterm")) {
+                    // Increase the number of answers.
                     $answercount++;
-                    // Check to see if the answer has the maximum grade
+                    // Check to see if the answer has the maximum grade.
                     if ($data['fraction'][$key] == 1) {
                         $maxgrade = true;
                     }
@@ -337,35 +344,35 @@ class qtype_algebra_edit_form extends question_edit_form {
             } catch (Exception $e) {
                 $errors['answer['.$key.']']=$e->getMessage();
                 // Return here because subsequent errors may be wrong due to not counting the answer
-                // which just failed to parse
+                // which just failed to parse.
                 return $errors;
             }
         }
-        // Check that we have at least one answer!
-        if ($answercount==0){
+        // Check that we have at least one answer.
+        if ($answercount==0) {
             $errors['answer[0]'] = get_string('notenoughanswers', 'quiz', 1);
         }
-        // Check that at least one question has the maximum possible grade
+        // Check that at least one question has the maximum possible grade.
         if ($maxgrade == false) {
             $errors['fraction[0]'] = get_string('fractionsnomax', 'question');
         }
 
         // Check for variables which are defined but never used.
         // Do this by looking for a non-empty array to be returned from array_diff.
-        if($d=array_diff($varlist,$ansvars)) {
-            // Loop over all the variables in the form
+        if ($d=array_diff($varlist, $ansvars)) {
+            // Loop over all the variables in the form.
             foreach ($vars as $key => $var) {
                 $trimvar = trim($var);
-                // If the variable is in the unused array then add the error message to that variable
-                if(in_array($trimvar,$d)) {
-                    $errors['variable['.$key.']'] = get_string('unusedvar','qtype_algebra');
+                // If the variable is in the unused array then add the error message to that variable.
+                if (in_array($trimvar, $d)) {
+                    $errors['variable['.$key.']'] = get_string('unusedvar', 'qtype_algebra');
                 }
             }
         }
 
-        // Check that the tolerance is greater than or equal to zero
-        if($data['tolerance']<0) {
-            $errors['tolerance']=get_string('toleranceltzero','qtype_algebra');
+        // Check that the tolerance is greater than or equal to zero.
+        if ($data['tolerance']<0) {
+            $errors['tolerance']=get_string('toleranceltzero', 'qtype_algebra');
         }
 
         return $errors;