svg icon, multiply setting

author: Jean-Michel Vedrine <vedrine@vedrine.org> 2018-01-27 10:35:50 +0100
committer: Jean-Michel Vedrine <vedrine@vedrine.org> 2018-01-27 10:35:50 +0100
commit: cd5af0a39cf71fd9c53886badf3ea0384d51fa22 (patch)
tree: 30e89940dbe9c74d23ba98297395b064534182fd
parent: 1bff8fd7cbd3904afda224ab1555e1e435528314 (diff)
8 files changed, 104 insertions, 31 deletions
diff --git a/displayformula.php b/displayformula.php
index 8c4cf8c..09f4cff 100644
--- a/displayformula.php
+++ b/displayformula.php
@@ -26,13 +26,16 @@
  * the mathJax filter to be present.
  */
 
+
 require_once('../../../config.php');
 require_once("$CFG->dirroot/question/type/algebra/parser.php");
-global $PAGE, $CFG;
 
+global $PAGE;
 require_login();
 
 $p = new qtype_algebra_parser;
+$validanswer = true;
+
 try {
     $query = urldecode($_SERVER['QUERY_STRING']);
     $m = array();
@@ -52,12 +55,17 @@ try {
         }
     }
 } catch (Exception $e) {
+    $validanswer = false;
     $texexp = get_string('parseerror', 'qtype_algebra', $e->getMessage());
 }
 $formatoptions = new stdClass;
 $formatoptions->para = false;
 $PAGE->set_context(context_system::instance());
-$text   = format_text($texexp, FORMAT_MOODLE, $formatoptions);
+if ($validanswer) {
+    $text = format_text($texexp, FORMAT_MOODLE, $formatoptions);
+} else {
+    $text = get_string('invalidanswer', 'qtype_algebra');
+}
 ?>
 <html>
     <head>
diff --git a/lang/en/qtype_algebra.php b/lang/en/qtype_algebra.php
index 7760584..26b6fe1 100644
--- a/lang/en/qtype_algebra.php
+++ b/lang/en/qtype_algebra.php
@@ -140,4 +140,8 @@ $string['port'] = 'Port of SAGE server';
 $string['uri'] = 'uri of SAGE server';
 $string['texdelimiters'] = 'Delimiters for TeX expressions';
 $string['dollars'] = '$$...$$';
-$string['brackets'] = '\[...\]';
-\ No newline at end of file
+$string['brackets'] = '\[...\]';
+$string['invalidanswer'] = 'Invalid or unrecongnized answer';
+$string['multiplyoperator'] = 'TeX operator for multiplication';
+$string['times'] = '\\times';
+$string['cdot'] = '\\cdot';
+\ No newline at end of file
diff --git a/parser.php b/parser.php
index 766797a..6068b25 100644
--- a/parser.php
+++ b/parser.php
@@ -21,20 +21,9 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-// From the PHP manual: check for the existance of lcfirst and
-// if not found create one.
-if (!function_exists('lcfirst')) {
-    /**
-     * Make a string's first character lowercase
-     *
-     * @param string $str
-     * @return string the resulting string.
-     */
-    function lcfirst( $str ) {
-        $str[0] = strtolower($str[0]);
-        return (string)$str;
-    }
-}
+require_once(__DIR__.'/../../../config.php');
+
+require_login();
 
 /**
  * Helper function which will compare two strings using their length only.
@@ -42,20 +31,22 @@ if (!function_exists('lcfirst')) {
  * This function is intended for use in sorting arrays of strings by their string
  * length. This is used to order arrays for regular expressions so that the longest
  * expressions are checked first.
+ * In this version, if both strings have equal length, string order is used. So this
+ * version of the sort is stable.
  *
  * @param $a first string to compare
  * @param $b second string to compare
- * @return -1 if $a is longer than $b, 0 if they are the same length and +1 if $a is shorter
+ * @return -1 if $a is longer than $b,  and +1 if $a is shorter
  */
 function qtype_algebra_parser_strlen_sort($a, $b) {
     // Get the two string lengths once so we don't have to repeat the function call.
     $alen = strlen($a);
     $blen = strlen($b);
-    // If the two lengths are equal return zero.
+    // If the two lengths are equal use strings order.
     if ($alen == $blen) {
-        return 0;
+        return ($a > $b) ? -1 : +1;
     }
-    // Otherwise return +1 if a > b or -1 if a < b.
+    // Otherwise return +1 if a is shorter or -1 if longer.
     return ($alen > $blen) ? -1 : +1;
 }
 
@@ -73,6 +64,7 @@ class qtype_algebra_parser_term {
     public $_arguments = array(); // Array of arguments in class form.
     public $_formats;           // Array of format strings.
     public $_nargs;             // Number of arguments for this term.
+    
     /**
      * Constructor for the generic parser term.
      *
@@ -434,7 +426,8 @@ class qtype_algebra_parser_term {
  * throw an exception in such cases.
  */
 class qtype_algebra_parser_nullterm extends qtype_algebra_parser_term {
-
+    /** @var The TeX multiply operator. */
+    public $id;
     /**
      * Constructs an instance of a null term.
      *
@@ -505,7 +498,7 @@ class qtype_algebra_parser_number extends qtype_algebra_parser_term {
             $this->_base = $m[1];
             $this->_exp = $m[2];
             $eformats = array('str' => '%sE%s',
-                            'tex' => '%s \\times 10^{%s}');
+                            'tex' => '%s \\' . get_config('qtype_algebra', 'multiplyoperator') . '10^{%s}');
             parent::__construct(self::NARGS, $eformats, $text);
         } else {
             $this->_base = $text;
@@ -654,7 +647,7 @@ class qtype_algebra_parser_variable extends qtype_algebra_parser_term {
             // Extract the remaining characters for use as the subscript.
             $this->_subscript = substr($text, strlen($m[1]));
             // If the first letter of the subscript is an underscore then remove it.
-            if ($this->_subscript[0] == '_') {
+            if (strlen($this->_subscript) != 0 && $this->_subscript[0] == '_') {
                 $this->_subscript = substr($this->_subscript, 1);
             }
             // Call the base class constructor with the variable text set to the combination of the
@@ -879,7 +872,7 @@ class qtype_algebra_parser_multiply extends qtype_algebra_parser_term {
      */
     public function __construct($text) {
         $this->mformats = array('*' => array('str' => '%s*%s',
-                                            'tex' => '%s \\times %s'),
+                                            'tex' => '%s \\' . get_config('qtype_algebra', 'multiplyoperator') . ' %s'),
                                 '.' => array('str' => '%s %s',
                                             'tex' => '%s %s',
                                             'sage' => '%s*%s')
@@ -900,7 +893,7 @@ class qtype_algebra_parser_multiply extends qtype_algebra_parser_term {
         parent::set_arguments($args);
         // Set the default explicit format.
         $this->_formats = $this->mformats['*'];
-        // Only allow the implicit multipication if the second argument is either a
+        // Only allow the implicit multiplication if the second argument is either a
         // special, variable, function or bracket and not negative. In all other cases the operator must be
         // explicitly written.
         if (is_a($args[1], 'qtype_algebra_parser_bracket') or
@@ -918,7 +911,7 @@ class qtype_algebra_parser_multiply extends qtype_algebra_parser_term {
             // power terms are parsed before multiplication ones and are required to
             // have two arguments.
             $powargs = $args[1]->arguments();
-            // Allow the implicit multipication if the power's first argument is either a
+            // Allow the implicit multiplication if the power's first argument is either a
             // special, variable, function or bracket and not negative.
             if (is_a($powargs[0], 'qtype_algebra_parser_bracket') or
                is_a($powargs[0], 'qtype_algebra_parser_variable') or
@@ -1728,4 +1721,3 @@ class qtype_algebra_parser {
 // Sort static arrays once here by inverse string length.
 usort(qtype_algebra_parser_variable::$greek, 'qtype_algebra_parser_strlen_sort');
 usort(qtype_algebra_parser::$functions, 'qtype_algebra_parser_strlen_sort');
-
diff --git a/pix/icon.svg b/pix/icon.svg
new file mode 100644
index 0000000..7f4ba9e
--- /dev/null
+++ b/pix/icon.svg
@@ -0,0 +1,56 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   version="1.1"
+   id="svg2"
+   preserveAspectRatio="xMinYMid meet"
+   height="16"
+   width="16"
+   style="isolation:isolate">
+  <metadata
+     id="metadata17">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:format>image/svg+xml</dc:format>
+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+        <dc:title></dc:title>
+      </cc:Work>
+    </rdf:RDF>
+  </metadata>
+  <defs
+     id="defs4">
+    <clipPath
+       id="a">
+      <path
+         id="path7"
+         d="M0 0h16v16H0z" />
+    </clipPath>
+  </defs>
+  <g
+     transform="translate(0,2.9491527)"
+     id="g9"
+     clip-path="url(#a)">
+    <path
+       id="path11"
+       d="m 16,6 0,-1 -16,0 0,6 16,0 0,-1 -15,0 0,-4 14,0 0,4 1,0 0,-4 z" />
+    <path
+       style="fill:#ffffff"
+       id="path13"
+       d="M 1,6 15,6 15,10 1,10 1,6 Z" />
+  </g>
+  <text
+     id="text3345"
+     y="5.6271191"
+     x="-3.2833064e-008"
+     style="font-style:normal;font-variant:normal;font-weight:bold;font-stretch:normal;font-size:7.5px;line-height:125%;font-family:Sans;-inkscape-font-specification:'Sans, Bold';text-align:start;letter-spacing:0px;word-spacing:0px;writing-mode:lr-tb;text-anchor:start;fill:#000000;fill-opacity:1;stroke:none;stroke-width:1px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1"
+     xml:space="preserve"><tspan
+       y="5.6271191"
+       x="-3.2833064e-008"
+       id="tspan3347">x=y</tspan></text>
+</svg>
diff --git a/settings.php b/settings.php
index 399c04c..525324a 100644
--- a/settings.php
+++ b/settings.php
@@ -47,4 +47,11 @@ if ($ADMIN->fulltree) {
             array('old' => new lang_string('dollars', 'qtype_algebra'),
                   'new' => new lang_string('brackets', 'qtype_algebra')
             )));
+    // TeX operator for multiplication.
+    $settings->add(new admin_setting_configselect('qtype_algebra/multiplyoperator',
+            new lang_string('multiplyoperator', 'qtype_algebra'),
+            '', 'times',
+            array('times' => new lang_string('times', 'qtype_algebra'),
+                  'cdot' => new lang_string('cdot', 'qtype_algebra')
+            )));
 }
diff --git a/tests/behat/preview.feature b/tests/behat/preview.feature
index 24f53ab..fec1b29 100644
--- a/tests/behat/preview.feature
+++ b/tests/behat/preview.feature
@@ -1,7 +1,7 @@
 @qtype @qtype_algebra
-Feature: Preview a Short answer question
+Feature: Preview an Algebra question
   As a teacher
-  In order to check my Short answer questions will work for students
+  In order to check my Algebra questions will work for students
   I need to preview them
 
   Background:
diff --git a/tests/parser_test.php b/tests/parser_test.php
index 5d5eaad..309984c 100644
--- a/tests/parser_test.php
+++ b/tests/parser_test.php
@@ -26,6 +26,8 @@
 defined('MOODLE_INTERNAL') || die();
 
 global $CFG;
+require_once($CFG->dirroot . '/question/engine/tests/helpers.php');
+require_once($CFG->dirroot . '/question/type/algebra/tests/helper.php');
 require_once($CFG->dirroot . '/question/type/algebra/parser.php');
 
 
@@ -61,5 +63,9 @@ class qtype_algebra_parser_test extends advanced_testcase {
         $this->assertEquals('\sin \left( 4  x_{} \right) + \cos \left( 5  y_{} \right)', $expr->tex());
         $expr = $p->parse('sin(6*x) + cos(7*y)');
         $this->assertEquals('\sin \left( 6  x_{} \right) + \cos \left( 7  y_{} \right)', $expr->tex());
+        $expr = $p->parse('3x y');
+        $this->assertEquals('3  x_{} y_{}', $expr->tex());
+        $expr = $p->parse('x*y*3');
+        $this->assertEquals('x_{} y_{} \times 3 ', $expr->tex());
     }
 }
diff --git a/version.php b/version.php
index aac10d7..7eb6e41 100644
--- a/version.php
+++ b/version.php
@@ -23,7 +23,7 @@
 defined('MOODLE_INTERNAL') || die();
 
 $plugin->component = 'qtype_algebra';
-$plugin->version   = 2017121900;
+$plugin->version   = 2018010400;
 
 $plugin->requires  = 2013050100;
 $plugin->release   = '1.6 for Moodle 2.8, ... 3.5';
author	Jean-Michel Vedrine <vedrine@vedrine.org>	2018-01-27 10:35:50 +0100
committer	Jean-Michel Vedrine <vedrine@vedrine.org>	2018-01-27 10:35:50 +0100
commit	cd5af0a39cf71fd9c53886badf3ea0384d51fa22 (patch)
tree	30e89940dbe9c74d23ba98297395b064534182fd
parent	1bff8fd7cbd3904afda224ab1555e1e435528314 (diff)