Flash Applets embedded in WeBWorK questions GraphLimit Example
Sample Problem with InverseGraph.swf embedded
This sample problem shows how to use this versatile applet.
A standard WeBWorK PG file with an embedded applet has six sections:
- A tagging and description section, that describes the problem for future users and authors,
- An initialization section, that loads required macros for the problem,
- A problem set-up section that sets variables specific to the problem,
- An Applet link section that inserts the applet and configures it, (this section is not present in WeBWorK problems without an embedded applet)
- A text section, that gives the text that is shown to the student, and
- An answer and solution section, that specifies how the answer(s) to the problem is(are) marked for correctness, and gives a solution that may be shown to the student after the problem set is complete.
The sample file attached to this page shows this; below the file is shown to the left, with a second column on its right that explains the different parts of the problem that are indicated above. A screenshot of the applet embedded in this WeBWorK problem is shown below:
Other useful links:
Flash Applets Tutorial
Things to consider in developing WeBWorK problems with embedded Flash applets
| PG problem file
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Explanation
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##DESCRIPTION
## Inverse Graph
## Sample problem to illustrate
## the use of the InverseGraph.swf
## Flash applet
##ENDDESCRIPTION
## KEYWORDS('calculus','derivatives', 'inverse functions')
## DBsubject('Calculus')
## DBchapter('Differentiation')
## DBsection('Derivatives of Inverse Functions')
## Date('8/16/2011')
## Author('Alex Yates')
## Institution('Cleveland State University')
## TitleText1('Calculus: Early Transcendentals 2e')
## EditionText1(2)
## AuthorText1('Rogawski')
## Section1('3.8')
## Problem1('9')
###########################################
# This work is supported in part by
# the National Science Foundation
# under the grant DUE-0941388.
###########################################
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This is the tagging and description
section of the problem. Note that
any line that begins with a "#" character is
a comment for other authors who
read the problem, and is not interpreted by
WeBWorK.
The description is provided to give a
quick summary of the problem so that
someone reading it later knows what it
does without having to read through all
of the problem code.
All of the tagging information exists to
allow the problem to be easily indexed.
Because this is a sample problem there
isn't a textbook per se, and we've used
some default tagging values. There is an on-line
list of current chapter and section names and a similar
list of keywords. The list of keywords should be comma separated and quoted (e.g., KEYWORDS('calculus','derivatives')).
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DOCUMENT();
loadMacros(
"PGstandard.pl",
"Parser.pl",
"freemanMacros.pl",
"AppletObjects.pl"
);
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This is the initialization section of the problem. The first executed line of the problem must be the DOCUMENT(); command. Note that every command must end with a semicolon.
The loadMacros command loads information that works behind the scenes. For our purposes we can usually just load the macros shown here and not worry about things further.
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The GraphLimits.swf applet will accept four different question types, specified with the $qtype variable. These are: limits, continuity, first_derivative and second_derivative. This sample problem is set to 'limits'.
The applet has solution/hint information embedded in it. When $hintState=0, this information is not shown. When $hintState=1, this information is revealed. The time parameter tracks the current date and time. The conditional compares that to the due date for the problem set (in the $dueDate scalar variable) and sets $hintState to 1 if the due date has passed and leaves $hintState set to 0 if the assignment is not yet due.
The four variables $x1, $x2, $x3 and $x4 are the x-coordinates of four points on the graph that the applet will set to be a removable discontinuity, a jump discontinuity or a cusp. The order of these phenomena is random as are the y-values chosen. The x-coordinates must be between -10 and 10.
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This is the Applet link section of the problem.
Those portions of the code that begin
the line with #
are comments and can be omitted or
replaced with comments appropriate
to your particular problem.
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You must include the section that
follows # Create link to
applet. If you are embedding
a different applet, from the Graph_Limit
applet, put your applet name in place of
'Graph_Limit' in the line $appletName =
"Graph_Limit";.
Enter the height of the applet
in the line height => '475',
in place of 475 and the width in the line
width => '425', in place of 425.
The code qq{
getQE("func").value=getApplet
("$appletName").getf_list($x1,"function");
getQE("rlimit").value=getApplet
("$appletName").getf_list($x2,"rightlimit");
getQE("llimit").value=getApplet
("$appletName").getf_list($x3,"leftlimit");
getQE("limit").value=getApplet
("$appletName").getf_list($x4,"limit");
}
is called when the 'Submit Answers'
button in the problem is pressed.
There is an external interface function
designed inside the applet. The function
name is 'getf_list'. These lines of code
call the function with javascript.
getf_list, takes two arguments:
the x-coordinate of a point, and a string
value. The string may be any of the
following four alternatives: "function",
"rightlimit", "leftlimit", "limit".
getf_list returns either
the value of the function at the x-coordinate,
or the specified limit. The line
getQE("func").value=getApplet
("$appletName").getf_list($x1,"function");
gets the value of the function at $x1
and stores this value in the hidden javascript
form field named "func".
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The lines $applet->configuration
(qq{<xml><hintState>$hintState</hintState>
<qtype>$qtype</qtype>
<seed>$problemSeed</seed>
<xlist x1='$x1' x2='$x2'
x3='$x3' x4='$x4' />
</xml>}); and $applet
->initialState(qq{<xml>
<hintState>$hintState</hintState>
<qtype>$qtype</qtype><seed>$problemSeed</seed>
<xlist x1='$x1' x2='$x2' x3='$x3' x4='$x4' />
</xml>}); configure the applet.
The configuration of the applet is done in xml.
The hintState is set to the variable
$hintState, the question type is set to
$qtype and the problem seed is the
WeBWorK environmental variable $problemSeed.
The variables $x1, $x2,
$x3 and $x4 are also
passed to the applet.
The hidden form fields are created in the code block:
TEXT(MODES(TeX=>"", HTML=><<'END_TEXT'));
<input type="hidden"
name="func" id="func" />
<input type="hidden"
name="llimit" id="llimit" />
<input type="hidden"
name="rlimit" id="rlimit" />
<input type="hidden"
name="limit" id="limit" />
END_TEXT
The line TEXT(MODES(TeX=>"", HTML=><<'END_TEXT'));
prevents the hidden fields from becoming part of the hard copy.
TEXT( MODES(TeX=>'object code',
HTML=>$applet->insertAll(
debug=>0,
includeAnswerBox=>0,
reinitialize_button=>$permissionLevel>=10,
))); actually embeds the applet
in the WeBWorK problem.
When the submit button is pressed, the
hidden form fields defined in this block are
filled with information from the applet.
The data from the hidden form fields is used
in these simple perl subroutines to define the
correct answers to the four questions that are
part of this WeBWorK problem.
The WeBWorK variable $answerString1 is the
content of the hidden form field "func".
$correctAnswer1 is the solution to the first
question. The solutions for the next two
questions are defined in a similar way.
The final question also has 'DNE' as a possible
correct answer for the student to enter. The
way that the applet is designed, the left and
right limits always exist.
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The text between the <script> tags detects whether the student is using Internet Explorer. If the student is using this browser, a warning is issued and the student is advised to use another browser. IE mis-sizes the applets. Some will work correctly when displayed at the wrong size, but others will fail. We do not recommend using IE with WeBWorK problems with Flash embedded.
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This is the text section
of the problem. The
TEXT(beginproblem()); line
displays a header for the problem, and
the Context()->texStrings
line sets how formulas are displayed in the
text, and we reset this after the text section.
Everything between the BEGIN_TEXT
and END_TEXT lines (each of which
must appear alone on a line) is shown to the
student.
Mathematical equations are delimited by
\( \)
(for inline equations) or \[ \]
(for displayed equations); in these contexts inserted
text is assumed to be TeX code.
There are a number of variables that set
formatting: $PAR is a paragraph
break (like \par in TeX).
This page gives a list
of variables like this. Finally, \{ \}
sets off code that will be executed
in the problem text. Here, ans_rule(35)
is a function that inserts an answer blank 35
characters wide.
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This is the answer
section of the problem. The problem answer
is set by the ANS( $correctAnswer1->cmp() );,
ANS( $correctAnswer2->cmp() );,
ANS( $correctAnswer3->cmp() );,
and ANS(num_cmp
($correctAnswer4,
strings=>['DNE'])); lines.
These compare the student's answer with the
answers returned from the applet. Answers 1-3
follow the same basic structure. The fourth
answer allows for either a numeric answer or
the string 'DNE' for limits that do not exist.
The solution is embedded in the applet and
becomes available when the due date has passed.
The ENDDOCUMENT(); command is the
last command in the file.
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License
The Flash applets developed under DUE-0941388 are protected under the following license:
Creative Commons Attribution-NonCommercial 3.0 Unported License.
