<?php
//============================================================================
// Name : dbLib.php
// Author : Lucas Woltmann
// Version : 1.0
// Date : 01-2017
// Description : Provides functions for managing the answers of the evaluation
// for students and tutors.
//============================================================================
define ("LOGDB", "db/eseeva.db");
/**
* Reads the database with the specified name and writes all log data to the corresponding arrays.
* Returns true if the log file has been successfully read, otherwise false.
* Is guaranteed to initialize the specified log arrays, even when the database file could not be
* read in which case they will simply be empty.
*
* @param string $fileName The database from which to read.
* @param int $student Whether the user is a student(1) or a tutor(0).
* @param array $questionData Will be created by this function and is passed by reference.
* Is an array of arrays that consists of the unique id, the question
* and the fields for the possible response options which contain
* the number of times that option has been selected.
* @param array $tutorData Will be created by this function and is passed by reference.
* Is an array of arrays that consists of the tutor name and the
* fields for the possible response options which contain the number
* of times that option has been selected.
* @param array $commentData Will be created by this function and is passed by reference.
* Is an array of string that resemble the different comments that
* have been made.
* @return boolean
*/
function ReadLogDatabase($fileName, $student, &$questionData, &$tutorData, &$commentData)
{
// init arrays regardless of the file not being found or eventual errors
$questionData = array();
$tutorData = array();
$commentData = array();
$questions = array();
$tutors = array();
$comments = array();
// return if the file does not exist
if (file_exists($fileName) == false)
return false;
// open the db
$handle = new SQLite3($fileName, SQLITE3_OPEN_READONLY);
if (!$handle)
return false;
$stmt = $handle->prepare("SELECT Answer FROM answers WHERE student=:student;");
if ($stmt)
{
$stmt->bindValue(':student', $student, SQLITE3_INTEGER);
$result = $stmt->execute();
//read to ararys, commentData does not need any further attention
PrepareAnswer($result, $questions, $tutors, $commentData);
}
else
{
$handle->close();
return false;
}
$handle->close();
//convert data into legacy data structure
ReadLogQuestionData($questions, $questionData);
ReadLogTutorData($tutors, $tutorData);
return true;
}
/**
* Writes the specified log arrays to a database with the specified name.
* Expects data in the same format as in the legacy version, but combines them to a single array
* which is going to be saved in the database.
* Returns true if the file was written successfully, otherwise false.
*
* @param string $fileName The name of the database to which the log data should be written.
* @param int $student Whether the user is a student(1) or a tutor(0).
* @param array $questionData The question data that should be written to the log file. Passed by reference.
* @param array $tutorData The tutor data that should be written to the log file. Passed by reference.
* @param array $commentData The list of comments that should be written to the log file. Passed by reference.
* @param string $key The key the user used.
* @return boolean
*/
function WriteLogDatabase($fileName, $student, &$questionData, &$tutorData, &$commentData, $key)
{
$answer = array($questionData, $tutorData, $commentData);
$handle = new SQLite3($fileName, SQLITE3_OPEN_READWRITE);
if (!$handle)
return false;
$stmt = $handle->prepare("UPDATE answers SET Status='activated', Student=:student, Answer=:answer WHERE KeyId=:keyid;");
if ($stmt)
{
$stmt->bindValue(':student', $student, SQLITE3_INTEGER);
$stmt->bindValue(':answer', serialize($answer), SQLITE3_BLOB);
$stmt->bindValue(':keyid', $key, SQLITE3_TEXT);
$result = $stmt->execute();
}
else
{
$handle->close();
return false;
}
$handle->close();
return true;
}
/**
* Legacy data management for the question data.
* Generates an array of arrays with all the questions.
* The first index of each subarray is the full title and the remaining indices are the votes (answers).
*
* @param array $formData $_POST reference. Passed by reference.
* @param array $questionData The array data that should be written to. Passed by reference.
* @param array $questionnaire The general structure (questions) of the questionnaire. Passed by reference.
*/
function AddQuestionData(&$formData, &$questionData, &$questionnaire)
{
foreach($formData as $id => $value)
{
if (!isset($questionnaire[$id]))
continue;
// get the type of the element with the same id as the form element from the questionnaire
$type = $questionnaire[$id][0];
// check if the element is a question on continue with the next one if that is not the case
if ($type != "Question")
continue;
// if there is not field for the current element in the question dsta array, create a new
// blank field containing the question and zeros for the number of times each answer was picked
if (array_key_exists($id, $questionData) == false)
$questionData[$id] = array($questionnaire[$id][1], 0, 0, 0, 0, 0, 0);
// increment the answer that was selected in the formular by one
$questionData[$id][(int)$value]++;
}
}
/**
* Legacy data management for the tutor data.
* Generates an array of arrays with the tutor.
* The first index of each subarray is the full name and the remaining indices are the votes (answers).
*
* @param array $formData $_POST reference. Passed by reference.
* @param array $tutorData The array data that should be written to. Passed by reference.
*/
function AddTutorData(&$formData, &$tutorData)
{
// get the name of the tutor from the form
$tutorName = $formData["tutorName"];
// get the selected answer of the tutorRating from the form
$tutorValue = $formData["tutorRating"];
// if there is no field for the current tutor in the tutor array, create a new
// nlank one with zeros for the number of times each answer was picked
if (array_key_exists($tutorName, $tutorData) == false)
$tutorData[$tutorName] = array(0, 0, 0, 0, 0, 0);
// increment the answer that was selected in the form by one
$tutorData[$tutorName][$tutorValue - 1]++;
}
/**
* Legacy data management for the comment data.
* Checks if a comment was left and writes it into the passed reference.
*
* @param array $formData $_POST reference. Passed by reference.
* @param string $commentData The array data that should be written to. Passed by reference.
*/
function AddCommentData(&$formData, &$commentData)
{
// if the comment field was filled, the comment
// array is appended by the new comment
if (trim($formData["comment"]) != "")
{
$commentData = $formData["comment"];
}
}
/**
* Reads all question data out of a provided log file array from the database.
* This function should NOT BE CALLED directly, instead the ReadLogDatabase function should be
* used to read a log file as a whole.
* All data is written to the specified question data array and
* True is returned if a valid question data block was found, otherwise false.
*
* @param array $questions An array from the database. Passed by reference.
* @param array $questionData An array to which all question data is written to. Passed by reference.
* @return boolean.
*/
function ReadLogQuestionData(&$questions, &$questionData)
{
foreach ((array)$questions as $user) {
foreach ($user as $id => $values) {
if (isset($questionData[$id]))
{
$questionData[$id] = SumArrays($values, $questionData[$id]);
}
else
{
$questionData[$id] = $values;
}
}
}
return true;
}
/**
* Reads all tutor data out of a provided log file array from the database.
* This function should NOT BE CALLED directly, instead the ReadLogDatabase function should be
* used to read a log file as a whole.
* All data is written to the specified question data array and
* True is returned if a valid tutor data block was found, otherwise false.
*
* @param array $tutors An array from the database. Passed by reference.
* @param array $tutorData An array to which all question data is written to. Passed by reference.
* @return boolean.
*/
function ReadLogTutorData(&$tutors, &$tutorData)
{
foreach ((array)$tutors as $user) {
foreach ($user as $id => $values) {
if (isset($tutorData[$id]))
{
$tutorData[$id] = SumArrays($values, $tutorData[$id]);
}
else
{
$tutorData[$id] = $values;
}
}
}
return true;
}
/**
* Reads all comment data out of a provided log file array from the database.
* This function should NOT BE CALLED directly, instead the ReadLogDatabase function should be
* used to read a log file as a whole.
* All data is written to the specified question data array and
* True is returned if a valid comment data block was found, otherwise false.
*
* @param array $comments An array from the database. Passed by reference.
* @param array $commentData An array to which all question data is written to. Passed by reference.
* @return boolean.
*/
function ReadLogCommentData(&$comments, &$commentData)
{
foreach ((array)$comments as $user) {
foreach ($user as $id => $values) {
if (isset($commentData[$id]))
{
$commentData[$id] = SumArrays($values, $commentData[$id]);
}
else
{
$commentData[$id] = $values;
}
}
}
return true;
}
/**
* Splits the three arrays from the 'Answer' column in the database into the legacy ararys.
*
* @param array $resultSet An array from the database. Passed by reference.
* @param array $questionsa An array to which all question data is written to. Passed by reference.
* @param array $tutors An array to which all tutor data is written to. Passed by reference.
* @param array $comments An array to which all comments data is written to. Passed by reference.
*/
function PrepareAnswer(&$resultSet, &$questions, &$tutors, &$comments)
{
$i = 0;
while($res = $resultSet->fetchArray(SQLITE3_ASSOC))
{
$res = unserialize($res["Answer"]);
$questions[$i] = $res[0];
$tutors[$i] = $res[1];
$comments[$i] = $res[2];
$i++;
}
}
/**
* Little helper function for adding up single user answers to a global statistic.
* Could be compared with a group by.
*
* @param array $array1 First array to merge/sum.
* @param array $array2 Second array to merge/sum.
* @return array Summed array by index.
*/
function SumArrays(&$array1, &$array2)
{
$result = array();
//the name
$result[0] = $array2[0];
$count = count($array2);
//start one index into counting, because index 0 is the name
for ($i=1; $i < $count; $i++) {
$result[$i] = $array1[$i] + $array2[$i];
}
return $result;
}
?>