From 47de80c701668556aae67e359f6a56ea8e83f622 Mon Sep 17 00:00:00 2001
From: tjhunt <tjhunt>
Date: Tue, 3 Mar 2009 05:11:55 +0000
Subject: [PATCH] Aiken question import: MDL-18423 Greater robustness when
 parsing.

---
 question/format/aiken/format.php | 102 +++++++++++++++++++------------
 1 file changed, 62 insertions(+), 40 deletions(-)

diff --git a/question/format/aiken/format.php b/question/format/aiken/format.php
index f11b01ad52..cde6211dbe 100644
--- a/question/format/aiken/format.php
+++ b/question/format/aiken/format.php
@@ -1,76 +1,98 @@
 <?php  // $Id$ 
 
-////////////////////////////////////////////////////////////////////////////
-/// AIKEN FORMAT
-///
-/// This Moodle class provides all functions necessary to import and export 
-/// one-correct-answer multiple choice questions in this format:
-///
-///  Question text
-///  A) Choice #1
-///  B) Choice #2
-///  C) Choice #3
-///  D) Choice #4
-///  ANSWER: B
-///    (blank line next not necessary since "AN" at the beginning of a line 
-///     triggers the question input and causes input to start all over.
-///
-///Only ONE correct answer is allowed with no feedback responses.
-///
-///Be sure to reword "All of the above" type questions as "All of these" (etc.) so that choices can
-///  be randomized
-///
-////////////////////////////////////////////////////////////////////////////
+///////////////////////////////////////////////////////////////////////////
+//                                                                       //
+// NOTICE OF COPYRIGHT                                                   //
+//                                                                       //
+// Moodle - Modular Object-Oriented Dynamic Learning Environment         //
+//          http://moodle.org                                            //
+//                                                                       //
+// Copyright (C) 1999 onwards Martin Dougiamas  http://dougiamas.com     //
+//                                                                       //
+// This program 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 2 of the License, or     //
+// (at your option) any later version.                                   //
+//                                                                       //
+// This program 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:                          //
+//                                                                       //
+//          http://www.gnu.org/copyleft/gpl.html                         //
+//                                                                       //
+///////////////////////////////////////////////////////////////////////////
 
+/**
+ * Aiken format - a simple format for creating multiple choice questions (with
+ * only one correct choice, and no feedback).
+ *
+ * The format looks like this:
+ *
+ * Question text
+ * A) Choice #1
+ * B) Choice #2
+ * C) Choice #3
+ * D) Choice #4
+ * ANSWER: B
+ *
+ * That is,
+ *  + question text all one one line.
+ *  + then a number of choices, one to a line. Each line must comprise a letter,
+ *    then ')' or '.', then a space, then the choice text.
+ *  + Then a line of the form 'ANSWER: X' to indicate the correct answer.
+ *
+ * Be sure to word "All of the above" type choices like "All of these" in
+ * case choices are being shuffled.
+ */
 class qformat_aiken extends qformat_default {
 
   function provide_import() {
     return true;
   }
 
-    function readquestions($lines){
+    function readquestions($lines) {
         $questions = array();
         $question = $this->defaultquestion();
         $endchar = chr(13); 
         foreach ($lines as $line) {
-            $stp = strpos($line,$endchar,0);
-            $newlines = explode($endchar,$line);
+            $stp = strpos($line, $endchar, 0);
+            $newlines = explode($endchar, $line);
             $foundQ = 0;
             $linescount = count($newlines);
             for ($i=0; $i < $linescount; $i++) {
                 $nowline = trim($newlines[$i]);
-                ///Go through the array and build an object called $question
-                ///When done, add $question to $questions
+                // Go through the array and build an object called $question
+                // When done, add $question to $questions
                 if (strlen($nowline) < 2) {
                     continue;
                 }
-                //                This will show everyline when file is being processed
-                //                print("$nowline<br />");
-                $leader = substr($nowline,0,2);
-                if (preg_match('/[A-Z][).]/',$leader)){
-                    //trim off the label and space
-                    $question->answer[] = htmlspecialchars(trim(substr($nowline,2)), ENT_NOQUOTES);
+                if (preg_match('/^[A-Z][).][ \t]/', $nowline)) {
+                    // A choice. Trim off the label and space, then save
+                    $question->answer[] = htmlspecialchars(trim(substr($nowline, 2)), ENT_NOQUOTES);
                     $question->fraction[] = 0;
                     $question->feedback[] = '';
                     continue;
                 }
-                if ($leader == "AN"){
-                    $ans = trim(substr($nowline,strpos($nowline,':') + 1));
-                    $ans = substr($ans,0,1);
-                    //A becomes 0 since array starts from 0
+                if (preg_match('/^ANSWER:/', $nowline)) {
+                    // The line that indicates the correct answer. This question is finised.
+                    $ans = trim(substr($nowline, strpos($nowline, ':') + 1));
+                    $ans = substr($ans, 0, 1);
+                    // We want to map A to 0, B to 1, etc.
                     $rightans = ord($ans) - ord('A');
                     $question->fraction[$rightans] = 1;
                     $questions[] = $question;
-                    //clear array for next question set
+
+                    // Clear array for next question set
                     $question = $this->defaultquestion();
                     continue;
                 } else {
-                    //Must be the first line since no leader
+                    // Must be the first line of a new question, since no recognised prefix.
                     $question->qtype = MULTICHOICE;
-                    $question->name = htmlspecialchars(substr($nowline,0,50));
+                    $question->name = htmlspecialchars(substr($nowline, 0, 50));
                     $question->questiontext = htmlspecialchars($nowline);
                     $question->single = 1;
-                    $question->feedback[] = "";
+                    $question->feedback[] = '';
                 }
             }
         }
-- 
2.39.5