Named answer rules

Add buttons to the MathQuill toolbar for a particular answer using a named answer rule.

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Complete Code

Download file: NamedAnswerRules.pg

POD for Macro Files

PG problem file

Explanation

DOCUMENT();
loadMacros(
    'PGstandard.pl',             'PGML.pl',
    'parserLinearInequality.pl', 'PGcourse.pl'
);

Preamble

Load the parserLinearInequality.pl macro so that a linear inequality answer can be used.

$a = random(2, 9);
$b = random(2, 9);
$c = random(2, 9);

Context('LinearInequality');
$inequalityAnswer = LinearInequality("x <= $a");

Context('Interval');
$intervalAnswer = Interval("(-inf, $a]");

Setup

Generate random variables $a, $b, and $c to use for coefficients in the linear inequality to be solved.

Then define a linear inequality answer in the LinearInequality context, and an interval answer in the Interval context.

BEGIN_PGML
Solve the following inequality.

>>[``[$b]x + [$c] \leq [$a * $b + $c]``]<<

Express the answer as an inequality:
[_]{$inequalityAnswer}{15}{ $inequalityAnswerName = NEW_ANS_NAME() }.

Express the answer in interval notation: [_]{$intervalAnswer}{15}
END_PGML

TEXT(MODES(TeX => '', HTML => <<"END_SCRIPT"));
<script>
window.addEventListener('DOMContentLoaded', () => {
    if (!window.answerQuills) return;
    answerQuills.$inequalityAnswerName.mathField.options.addToolbarButtons(
        [
            {
                id: 'leq',
                latex: '\\leq',
                tooltip: 'less than or equal (<=)',
                icon: '\\leq'
            },
            {
                id: 'geq',
                latex: '\\geq',
                tooltip: 'greater than or equal (>=)',
                icon: '\\geq'
            }
        ],
        9
    );
});
</script>
END_SCRIPT

Statement

Ask the student to solve the inequality, and give the answer as both a linear inequality and an interval.

A named answer is needed for the linear inequality answer in order to add toolbar buttons to the MathQuill toolbar for that answer. Do this with the third option for a PGML answer by calling the NEW_ANS_NAME function and assigning that to the variable $inequalityAnswerName. Never use hard coded made up answer names in problems. Always obtain an answer name using the NEW_ANS_NAME method. Problems that use hard coded made up answer names will not work correctly in many situations. The interval answer does not need to be named.

Finally inject a script tag to the end of the problem text. It is important that this JavaScript code be executed after the PG MathQuill JavaScript so that the window.answerQuills variable will be defined. One way to accomplish this is by executing the code in the DOMContentLoaded event.

Add the buttons to the toolbar for the linear inequality answer by calling the addToolbarButtons function of the options object for the mathField associated to the $inequalityAnswerName answer quill. The first argument for the addToolbarButtons function can be either a single toolbar button definition or an array of toolbar button definitions (see below for a description of a toolbar button definition). The second argument can be either a number which is the zero based position at which the new toolbar buttons will be inserted, or the id of an existing toolbar button after which the new toolbar buttons will be inserted (note the ids of the default toolbar buttons in order are frac, abs, sqrt, nthroot, exponent, infty, pi, vert, cup, and text). Note that the second argument can be a negative number which counts backward from the end. In fact the second argument can be entirely omitted. In that case a position of -1 is used which will insert the new button before the last toolbar button (initially the text button).

A toolbar button is defined as a JavaScript object with the four properties id, latex, tooltip, and icon.

  • The id can be any string, but should not have the same id of another toolbar button.
  • The latex for a button is the LaTeX code that will be inserted into the MathQuill input when the toolbar button is pressed. Make sure that backslashes are escaped with another backslash.
  • The tooltip is text that will be shown in a tooltip when the button on the toolbar has keyboard focus or is hovered over by the mouse cursor. Note that the toolbar text should include a brief textual description of what will be inserted when the button is pressed, and in parentheses after that the keyboard sequence that can be typed into the MathQuill input to insert the same thing that pressing the button will insert.
  • The icon is the LaTeX code for icon that will be shown in a static MathQuill field on the toolbar button. Make sure that backslashes are escaped with another backslash.

A button can also be removed from the toolbar for an answer using the removeToolbarButtons function. The only argument for this function is a string id or array of string ids for existing toolbar buttons to be removed. For example, answerQuills.$inequalityAnswerName.mathField.options.removeToolbarButtons('cup'); would remove the union button from the toolbar, and answerQuills.$inequalityAnswerName.mathField.options.removeToolbarButtons([ 'pi', 'cup' ]); would remove the pi and union buttons from the toolbar. It is important to note that removing a toolbar button does not prevent a student from entering what the toolbar button would insert. It merely removes the toolbar button. For example, if the cup button is removed, a student could still type “union” to enter a union symbol.

BEGIN_PGML_SOLUTION
Solution explanation goes here.
END_PGML_SOLUTION

ENDDOCUMENT();

Solution

A solution should be provided here.