diff options
Diffstat (limited to 'questiontype.php')
| -rw-r--r-- | questiontype.php | 229 |
1 files changed, 110 insertions, 119 deletions
diff --git a/questiontype.php b/questiontype.php index 0d816e3..177ddff 100644 --- a/questiontype.php +++ b/questiontype.php @@ -44,13 +44,13 @@ class qtype_algebra extends question_type { * @return an array with the table name (first) and then the column names (apart from id and questionid) */ public function extra_question_fields() { - return array('qtype_algebra', + return array('qtype_algebra_options', 'compareby', // Name of comparison algorithm to use 'nchecks', // Number of evaluate checks to make when comparing by evaluation 'tolerance', // Max. fractional difference allowed for evaluation checks 'allowedfuncs', // Comma separated list of functions allowed in responses 'disallow', // Response which may be correct but which is not allowed - 'answerprefix' // String which is placed in front of the asnwer box + 'answerprefix' // String which is placed in front of the asnwer box. ); } @@ -89,25 +89,25 @@ class qtype_algebra extends question_type { */ public function save_question_variables($question) { global $DB; - // Create the results class + // Create the results class. $result = new stdClass; - // Get all the old answers from the database as an array + // Get all the old answers from the database as an array. if (!$oldvars = $DB->get_records('qtype_algebra_variables', array('question' => $question->id), 'id ASC')) { $oldvars = array(); } - // Create an array of the variable IDs for the question + // Create an array of the variable IDs for the question. $variables = array(); - // Loop over all the answers in the question form and write them to the database + // Loop over all the answers in the question form and write them to the database. foreach ($question->variable as $key => $varname) { - // Check to see that there is a variable and skip any which are empty + // Check to see that there is a variable and skip any which are empty. if ($varname == '') { continue; } // Get the old variable from the array and overwrite what is required, if there - // is no old variable then we skip to the 'else' clause - if ($oldvar = array_shift($oldvars)) { // Existing variable, so reuse it + // is no old variable then we skip to the 'else' clause. + if ($oldvar = array_shift($oldvars)) { // Existing variable, so reuse it. $var = $oldvar; $var->name = trim($varname); $var->min = trim($question->varmin[$key]); @@ -116,22 +116,21 @@ class qtype_algebra extends question_type { if (!$DB->update_record('qtype_algebra_variables', $var)) { throw new Exception("Could not update algebra question variable (id=$var->id)"); } - } - // This is a completely new variable so we have to create a new record - else { + } else { + // This is a completely new variable so we have to create a new record. $var = new stdClass; $var->name = trim($varname); $var->question = $question->id; $var->min = trim($question->varmin[$key]); $var->max = trim($question->varmax[$key]); - // Insert a new record into the database table + // Insert a new record into the database table. if (!$var->id = $DB->insert_record('qtype_algebra_variables', $var)) { throw new Exception("Could not insert algebra question variable '$varname'!"); } } - // Add the variable ID to the array of IDs + // Add the variable ID to the array of IDs. $variables[] = $var->id; - } // end loop over variables + } // End loop over variables. // Delete any left over old variables records. foreach ($oldvars as $oldvar) { @@ -158,20 +157,20 @@ class qtype_algebra extends question_type { global $CFG, $DB; $context = $question->context; - // Create the results class + // Create the results class. $result = new stdClass; - // Get all the old answers from the database as an array - if (!$oldanswers = $DB->get_records('question_answers', array('question' => $question->id), 'id ASC')) { //'question', $question->'id ASC')) { - $oldanswers = array(); + // Get all the old answers from the database as an array. + if (!$oldanswers = $DB->get_records('question_answers', array('question' => $question->id), 'id ASC')) { + $oldanswers = array(); } - // Create an array of the answer IDs for the question + // Create an array of the answer IDs for the question. $answers = array(); // Set the maximum answer fraction to be -1. We will check this at the end of our - // loop over the questions and if it is not 100% (=1.0) then we will flag an error + // loop over the questions and if it is not 100% (=1.0) then we will flag an error. $maxfraction = -1; - // Loop over all the answers in the question form and write them to the database + // Loop over all the answers in the question form and write them to the database. foreach ($question->answer as $key => $answerdata) { // Check for, and ignore, completely blank answer from the form. if (trim($answerdata) == '' && $question->fraction[$key] == 0 && @@ -200,14 +199,13 @@ class qtype_algebra extends question_type { throw new Exception("Could not update algebra question answer (id=$answer->id)"); } - $answers[] = $answer->id; if ($question->fraction[$key] > $maxfraction) { $maxfraction = $question->fraction[$key]; } - } // end loop over answers + } // End loop over answers. - // Perform sanity check on the maximum fractional grade which should be 100% + // Perform sanity check on the maximum fractional grade which should be 100%. if ($maxfraction != 1) { $maxfraction = $maxfraction * 100; throw new Exception(get_string('fractionsnomax', 'quiz', $maxfraction)); @@ -237,20 +235,20 @@ class qtype_algebra extends question_type { */ public function save_question_options($question) { // Start a try block to catch any exceptions generated when we attempt to parse and - // then add the answers and variables to the database + // then add the answers and variables to the database. try { - // First write out all the variables associated with the question + // First write out all the variables associated with the question. $variables=$this->save_question_variables($question); // Loop over all the answers in the question form and parse them to generate - // a parser string. This ensures a constant formatting is stored in the database + // a parser string. This ensures a constant formatting is stored in the database. foreach ($question->answer as &$answer) { $expr=$this->parse_expression($answer); - // TODO detect invalid answer and issue a warning + // TODO detect invalid answer and issue a warning. $answer=$expr->sage(); } - // Now we need to write out all the answers to the question to the database + // Now we need to write out all the answers to the question to the database. $answers=$this->save_question_answers($question); } catch (Exception $e) { @@ -264,26 +262,24 @@ class qtype_algebra extends question_type { // Process the allowed functions field. This code just sets up the variable, it is saved // in the parent class' save_question_options method called at the end of this method - // Look for the 'all' option. If we find it then set the string to an empty value - if(array_key_exists('all',$question->allowedfuncs)) { + // Look for the 'all' option. If we find it then set the string to an empty value. + if (array_key_exists('all', $question->allowedfuncs)) { $question->allowedfuncs=''; - } - // Not all functions are allowed so set allowed functions to those which are - else { + } else { + // Not all functions are allowed so set allowed functions to those which are. // Create a comma separated string of the function names which are stored in the - // keys of the array - $question->allowedfuncs=implode(',',array_keys($question->allowedfuncs)); + // keys of the array. + $question->allowedfuncs=implode(',', array_keys($question->allowedfuncs)); } // Call the parent method to write the extensions fields to the database. This either returns null - // or an error object so if we get anything then return it otherwise return our existing + // or an error object so if we get anything then return it otherwise return our existing. $parentresult = parent::save_question_options($question); if ($parentresult !== null) { - // Parent function returns null if all is OK + // Parent function returns null if all is OK. return $parentresult; - } - // Otherwise just return true - this mimics the shortanswer return format - else { + } else { + // Otherwise just return true - this mimics the shortanswer return format. return true; } } @@ -303,43 +299,37 @@ class qtype_algebra extends question_type { public function get_question_options($question) { // Get the information from the database table. If this fails then immediately bail. // Note unlike the save_question_options base class method this method DOES get the question's - // answers along with any answer extensions + // answers along with any answer extensions. global $DB; - if(!parent::get_question_options($question)) { + if (!parent::get_question_options($question)) { return false; } - // Check that we have answers and if not then bail since this question type requires answers - if(count($question->options->answers)==0) { + // Check that we have answers and if not then bail since this question type requires answers. + if (count($question->options->answers)==0) { notify('Failed to load question answers from the table question_answers for questionid ' . $question->id); return false; } - // Now get the variables from the database as well + // Now get the variables from the database as well. $question->options->variables = $DB->get_records('qtype_algebra_variables', array('question' => $question->id)); + // Check that we have variables and if not then bail since this question type requires variables. - - - //, 'id ASC'); - // Check that we have variables and if not then bail since this question type requires variables - - if(count($question->options->variables)==0) { + if (count($question->options->variables)==0) { notify('Failed to load question variables from the table qtype_algebra_variables '. "for questionid $question->id"); return false; } - - // Check to see if there are any allowed functions - if($question->options->allowedfuncs!='') { - // Extract the allowed functions as an array - $question->options->allowedfuncs=explode(',',$question->options->allowedfuncs); - } - // Otherwise just create an empty array - else { + // Check to see if there are any allowed functions. + if ($question->options->allowedfuncs!='') { + // Extract the allowed functions as an array. + $question->options->allowedfuncs=explode(',', $question->options->allowedfuncs); + } else { + // Otherwise just create an empty array. $question->options->allowedfuncs=array(); } - // Everything worked so return true + // Everything worked so return true. return true; } @@ -363,33 +353,32 @@ class qtype_algebra extends question_type { return false; } if ($data['@']['type'] == 'algebra') { - // Import the common question headers + // Import the common question headers. $qo = $format->import_headers($data); - // Set the question type + // Set the question type. $qo->qtype='algebra'; - $qo->compareby = $format->getpath($data, array('#','compareby',0,'#'),'eval'); - $qo->tolerance = $format->getpath($data, array('#','tolerance',0,'#'),'0'); - $qo->nchecks = $format->getpath($data, array('#','nchecks',0,'#'),'10'); - $qo->disallow = $format->getpath($data, array('#','disallow',0,'#','text',0,'#'),'',true); - $allowedfuncs = $format->getpath($data, array('#','allowedfuncs',0,'#'), ''); - if($allowedfuncs=='') { + $qo->compareby = $format->getpath($data, array('#', 'compareby', 0, '#'), 'eval'); + $qo->tolerance = $format->getpath($data, array('#', 'tolerance', 0, '#'), '0'); + $qo->nchecks = $format->getpath($data, array('#', 'nchecks', 0, '#'), '10'); + $qo->disallow = $format->getpath($data, array('#', 'disallow', 0, '#', 'text', 0, '#'), '', true); + $allowedfuncs = $format->getpath($data, array('#', 'allowedfuncs', 0, '#'), ''); + if ($allowedfuncs=='') { $qo->allowedfuncs=array('all' => 1); + } else { + // Need to separate the allowed functions into an array of strings and then + // flip the values of this array into the keys because this is what the + // save options method requires. + $qo->allowedfuncs=array_flip(explode(',', $allowedfuncs)); } - // Need to separate the allowed functions into an array of strings and then - // flip the values of this array into the keys because this is what the - // save options method requires - else { - $qo->allowedfuncs=array_flip(explode(',',$allowedfuncs)); - } - $qo->answerprefix = $format->getpath($data, array('#','answerprefix',0,'#','text',0,'#'),'',true); + $qo->answerprefix = $format->getpath($data, array('#', 'answerprefix', 0, '#', 'text', 0, '#'), '', true); - // Import all the answers + // Import all the answers. $answers = $data['#']['answer']; $a_count = 0; - // Loop over each answer block found in the XML - foreach($answers as $answer) { - // Use the common answer import function in the format class to load the data + // Loop over each answer block found in the XML. + foreach ($answers as $answer) { + // Use the common answer import function in the format class to load the data. $ans = $format->import_answer($answer); $qo->answer[$a_count] = $ans->answer['text']; $qo->fraction[$a_count] = $ans->fraction; @@ -397,14 +386,16 @@ class qtype_algebra extends question_type { ++$a_count; } - // Import all the variables + // Import all the variables. $vars = $data['#']['variable']; $v_count = 0; - // Loop over each answer block found in the XML - foreach($vars as $var) { - $qo->variable[$v_count] = $format->getpath($var, array('@','name'),0); - $qo->varmin[$v_count] = $format->getpath($var, array('#','min',0,'#'),'0',false,get_string('novarmin','qtype_algebra')); - $qo->varmax[$v_count] = $format->getpath($var, array('#','max',0,'#'),'0',false,get_string('novarmax','qtype_algebra')); + // Loop over each answer block found in the XML. + foreach ($vars as $var) { + $qo->variable[$v_count] = $format->getpath($var, array('@', 'name'), 0); + $qo->varmin[$v_count] = $format->getpath($var, + array('#', 'min', 0, '#'), '0', false, get_string('novarmin', 'qtype_algebra')); + $qo->varmax[$v_count] = $format->getpath($var, + array('#', 'max', 0, '#'), '0', false, get_string('novarmax', 'qtype_algebra')); ++$v_count; } @@ -429,19 +420,19 @@ class qtype_algebra extends question_type { */ public function export_to_xml($question, qformat_xml $format, $extra=null) { $expout=''; - // Create a text string of the allowed functions from the array - $allowedfuncs=implode(',',$question->options->allowedfuncs); - // Write out all the extra fields belonging to the algebra question type + // Create a text string of the allowed functions from the array. + $allowedfuncs=implode(',', $question->options->allowedfuncs); + // Write out all the extra fields belonging to the algebra question type. $expout .= " <compareby>{$question->options->compareby}</compareby>\n"; $expout .= " <tolerance>{$question->options->tolerance}</tolerance>\n"; $expout .= " <nchecks>{$question->options->nchecks}</nchecks>\n"; - $expout .= " <disallow>".$format->writetext($question->options->disallow,1,true)."</disallow>\n"; + $expout .= " <disallow>".$format->writetext($question->options->disallow, 1, true)."</disallow>\n"; $expout .= " <allowedfuncs>$allowedfuncs</allowedfuncs>\n"; - $expout .= " <answerprefix>".$format->writetext($question->options->answerprefix,1,true). + $expout .= " <answerprefix>".$format->writetext($question->options->answerprefix, 1, true). "</answerprefix>\n"; - // Write out all the answers + // Write out all the answers. $expout .= $format->write_answers($question->options->answers); - // Loop over all the variables for the question and write out all their details + // Loop over all the variables for the question and write out all their details. foreach ($question->options->variables as $var) { $expout .= "<variable name=\"{$var->name}\">\n"; $expout .= " <min>{$var->min}</min>\n"; @@ -451,13 +442,13 @@ class qtype_algebra extends question_type { return $expout; } - // Gets all the question responses + // Gets all the question responses. public function get_all_responses(&$question, &$state) { $result = new stdClass; $answers = array(); - // Loop over all the answers + // Loop over all the answers. if (is_array($question->options->answers)) { - foreach ($question->options->answers as $aid=>$answer) { + foreach ($question->options->answers as $aid => $answer) { $r = new stdClass; $r->answer = $answer->answer; $r->credit = $answer->fraction; @@ -470,42 +461,42 @@ class qtype_algebra extends question_type { } /** - * Parses the given expression with the parser if required. - * - * This method will check to see if the argument it is given is already a parsed - * expression and if not will attempt to parse it. - * - * @param $expr expression which will be parsed - * @param $question question containing the expression or null if none - * @return top term of the parse tree or a string if an exception is thrown - */ - function parse_expression($expr) { - // Check to see if this is already a parsed expression - if(is_a($expr, 'qtype_algebra_parser_term')) { - // It is a parsed expression so simply return it + * Parses the given expression with the parser if required. + * + * This method will check to see if the argument it is given is already a parsed + * expression and if not will attempt to parse it. + * + * @param $expr expression which will be parsed + * @param $question question containing the expression or null if none + * @return top term of the parse tree or a string if an exception is thrown + */ + public function parse_expression($expr) { + // Check to see if this is already a parsed expression. + if (is_a($expr, 'qtype_algebra_parser_term')) { + // It is a parsed expression so simply return it. return $expr; } // Check whether we have a state object or a simple string. If a state - // then replace it with the response string - if(isset($expr->responses[''])) { + // then replace it with the response string. + if (isset($expr->responses[''])) { $expr=$expr->responses['']; } // Create an empty array of variable names for the parser (no variable checking here as it is done in the form validation - // TODO see in case of import + // TODO see in case of import. $varnames=array(); // We now assume that we have a string to parse. Create a parser instance to - // to this and return the parser expression at the top of the parse tree + // to this and return the parser expression at the top of the parse tree. $p=new qtype_algebra_parser; - // Perform the actual parsing inside a try-catch block so that any exceptions - // can be caught and converted into errors + // Perform the actual parsing inside a try-catch block so that any exceptions. + // can be caught and converted into errors. try { - return $p->parse($expr,$varnames); - } catch(Exception $e) { + return $p->parse($expr, $varnames); + } catch (Exception $e) { // If the expression cannot be parsed then return a null term. This will // make Moodle treat the answer as wrong. // TODO: Would be nice to have support for 'invalid answer' in the quiz - // engine since an unparseable response is usually caused by a silly typo + // engine since an unparseable response is usually caused by a silly typo. return new qtype_algebra_parser_nullterm; } } |