PHP 5/MySQL Programming- P48 docx

If the user wants to see an existing test, I open the file for read access and grab the first three lines, which correspond to the $quizName, $quizEmail, and $quizPwdfields.. The quiz ma

Invalid Password!

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HERE;

} else {

//check to see if user has chosen a form to edit

if ($editFile == “new”){

//if it’s a new file, put in some dummy values

$quizName = “sample test”;

$quizEmail = “root@localhost”;

$quizData = “q:a:b:c:d:correct”;

$quizPwd = “php”;

} else {

//open up the file and get the data from it

$fp = fopen($editFile, “r”);

$quizName = fgets($fp);

$quizEmail = fgets($fp);

$quizPwd = fgets($fp);

while (!feof($fp)){

$quizData = fgets($fp);

} // end while

fclose($fp);

} // end ‘new form’ if

I decided to code the value absolute(from the name of this book series) as an

administrative password Each test has its own password and the administrative

functions (like editing a quiz) have their own passwords If the passwordfield has

any other value besides my chosen password, the program indicates a problem

and refuses to move forward

An administrative password keeps casual snoops out of your system, but it’s nowhere near bullet-proof security This system is not appropriate for situations where you must absolutely secure the tests.

Once you know the user is authorized to edit tests, determine if it’s a new or

existing quiz If the quiz is new, I simply add sample data to the variables, which

are used for the upcoming form If the user wants to see an existing test, I open

the file for read access and grab the first three lines, which correspond to the

$quizName, $quizEmail, and $quizPwdfields A foreachloop loads the rest of the file

into the $quizDatavariable

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You might wonder why the quiz needs a password field if it took a password to get to this form The quiz system has multiple levels of security Anybody can get

to the quizBuilder.php page However, to move to one of the other pages, the user must have the right kind of password Only an administrator should go to the editPage and showLog programs, so these programs require special adminis-trative password access Each quiz also has an associated password The quiz master file stores the password so you can associate a different password for each quiz In this way, the users authorized to take one test won’t take other tests (and confuse your log files).

Printing the Form

Once the variables are loaded with appropriate values, it’s a simple matter to print an HTML form and let the user edit the quiz The form is almost all pure HTML with the quiz variables interpolated into the appropriate places:

print <<<HERE

<form action = “writeQuiz.php”

method = “post”>

<table border = 1>

<tr>

<th>Quiz Name</th>

<td>

<input type = “text”

name = “quizName”

value = “$quizName”>

</td>

</tr>

<tr>

<th>Instructor email</th>

<td>

<input type = “text”

name = “quizEmail”

value = “$quizEmail”>

</td>

</tr>

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<th>Password</th>

<td>

<input type = “text”

name = “quizPwd”

value = “$quizPwd”>

<tr>

<td rowspan = 1

colspan = 2>

<textarea name = “quizData”

rows = 20 cols = 60>

$quizData</textarea>

</td>

</tr>

<tr>

<td colspan = 2><center>

<input type = “submit”

value = “make the quiz”>

</center></td>

</tr>

</table>

</form>

HERE;

} // end if

?>

</body>

</html>

Writing the Test

The administrator has finished editing a quiz file Now what? That quiz file must be

stored to the file system and an HTML page generated for the quiz The writeQuiz.php

program performs these duties

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Setting Up the Main Logic

Creating two files is your first job The quiz name can be the filename’s foundation, but many file systems choke at spaces within filenames I use the str_replace() function to replace all spaces in $quizNameto underscore characters (_) Then I cre-ate a filename ending in .masfor the master file and another filename ending in .htmlfor the actual quiz

To create the HTML file, I open it for write output Then I use the buildHTML() function (described shortly) to build the HTML code, write that code to the HTML file, and close the file The master file is built pretty much the same way, except

it calls the buildMas()function to create the appropriate text for the file

<html>

<head>

<title>Write Quiz</title>

</head>

<body>

<?

//given a quiz file from editQuiz,

//generates a master file and an HTML file for the quiz

//open the output file

$fileBase = str_replace(“ “, “_”, $quizName);

$htmlFile = $fileBase “.html”;

$masFile = $fileBase “.mas”;

$htfp = fopen($htmlFile, “w”);

$htData = buildHTML();

fputs($htfp, $htData);

fclose($htfp);

$msfp = fopen($masFile, “w”);

$msData = buildMas();

fputs($msfp, $msData);

fclose($msfp);

//preview the actual master file

print <<<HERE

<pre>

$msData

</pre>

HERE;

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To make sure things are going well, I add a check to the end of the page that

prints out the master file’s actual contents This program’s output lets the

administrator see that the test is working correctly The administrator can take

the test and submit it to the grading program from this page If there is a

prob-lem, it’s convenient to have the actual contents of the .mas file visible on the

page Of course, the final HTML page does not contain this data, because it holds

the answers

Building the Master File

The master file routine is very straightforward:

function buildMas(){

//builds the master file

global $quizName, $quizEmail, $quizPwd, $quizData;

$msData = $quizName “\n”;

$msData = $quizEmail “\n”;

$msData = $quizPwd “\n”;

$msData = $quizData;

return $msData;

} // end buildMas

The critical part is remembering the file structure rules, so any program that

reads this file doesn’t get confused The elements come in this order:

• Quiz name

• A newline character

• The $quizEmailvariable

• The $quizPwdvariable

• All $quizData(usually several lines)

Note that the function doesn’t actually store the data to the file, but returns it to

the main program This allows me to write the data to both the file and to the page

Building the HTML File

The function that creates the HTML is a little more involved, but is manageable

The basic strategy is this: Build an HTML form containing all the questions For

each line of the master file, build a radio group Place the question and all the

possible answers in a set of nested <ol>elements At the end of the page, there

should be one submitbutton When the user clicks the submitbutton, the system

calls the gradeQuiz.phppage, which evaluates the user’s responses

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