The subject field is a text string that will appear as the subject field of

the e-mail message. The subject string should be plain text with no

Xhtml tags or character entities. The message field is a text string

that will appear as the body of the message. Unless special syntax

(called MIME format) is used, the message field should also be plain

text with no XHTML tags or character entities.

A fourth optional additional_headers argument can include addi-

tional headers that are typically found in e-mail messages, such as

From, Cc, Bcc, and Date headers. For the From, Cc, and Bcc headers,

the same address specifier syntax is used as in the recipient(s) field.

The additional_headers argument needs to be formatted to con-

form to the syntax of headers in the Internet Message Format docu-

mentation. Each header needs to be on its own line. The line must

start with the header name, followed by a colon, a space, and the

Value of the header element. For example:

Date: Fri, 03 Apr 2009 16:05:50 -0400

From: Linda M. Jones <linda@jones.example.com>

CC: Mary R. Jones <mary@jones.example.com>

Any valid e-mail header may be added using the additional_headers

argument. However, depending on the configuration of PHP and the

mail program on the Web server, some headers may be excluded and

others may be overwritten with values defined by the server.

The mail() function returns a value of TRUE if a message was sent

successfully or FALSE if it was not. The return value comes in handy

when displaying a status message for the user, which will be discussed

next. The following example demonstrates how to send the results of

the scholarship form as a simple e-mail message:

$To = "webmaster@example.edu";

$Subject = "Message from the Web Form";

$Message = $formMessage;

$Headers="From: $fname $lName <$emailAddress>";

mail ($To, $Subject, $Message, $Headers);

Displaying a Status Message for the User

Once all required fields on the form have been filled in and validated,

and any action such as sending an e-mail message has been com-

pleted, the user should receive a status message in the browser. A

standard practice as part of the status message is to thank the user for

completing the form. You can also display the results of any actions

initiated while processing the form data. For example, the status mes-

sage could display “Your message has been sent” if the mail() func-

tion returned TRUE, or “Your message could not be sent at this time” if

the mail() function returned FALSE.

To send e-mail from the scholarship form:

1.

Electronic

207

Reopen the process_Scholarship.php script in your text

editor.

Replace the else portion of the final if...else statement

with the following code block:

{ // Send an e-mail

// replace the "recipient@example.edu" with your

// e-mail address

$To = "recipient@mail.edu";

$Subject = "Scholarship Form Results";

$Message = "Student Name: " . $firstName. " " .

$lastName;

}

2.

3.

Add the following code immediately before the end of the

final code block of the PHP script section. Using advanced

escaping and coding the message in XHTML rather than in

Handling User Input

the PHP script section allows you to more easily format the

data using CSS.

?>

<h2 style = "text-align:center">Scholarship

Form</h2>

<p style = "line-height:200%">Thank you for filling

out the scholarship form<?php

if (!empty($firstName))

208

4.

5.

Save the file and upload it the server.

Open the Scholarship.html page in the Web browser by enter-

ing the following URL: http://<yourserver>/PHP_Projects/

Chapter.04/Chapter/Scholarship.html. Figure 4-9 shows the

status message displayed in the browser window after the

form has been successfully submitted.

Figure 4-9

Sending e-mail for the scholarship form

6.

Close your Web browser window.

Short Quiz

1.

Under which conditions does the empty() function return

TRUE?

Explain the process of efficiently handling multiple errors.

Define the term “advanced escaping from XHTML”.

What are the three required arguments of the mail()

function?

2.

3.

4.

Creating an All-in-One Form

If you have a large form with many fields, or if your form requires

intensive processing, it would be more efficient to use separate docu-

ments for the Web form and the form handler, as you have done so far

in this chapter with the XHTML Web form (Scholarship.html) and

the PHP script that processed the form (process_Scholarship.php).

This is known as a two-part form, because you have one page that dis-

plays the form and one page that processes the form data. However,

for simple forms that require only minimal processing, it’s often

easier to use an All-in-One form—a single script used to display a

Web form and process its data. When the user clicks the submit but-

ton, the script submits the form data to the current script. You then

use validation code to determine if data exists when the page is first

displayed, and to ensure that the user has completed all the required

form fields and has entered valid responses.

The PHP script for an All-in-One form can be organized using two

conditionals. The first conditional determines if the data has been

submitted and needs to be validated. The second conditional deter-

mines if the form needs to be redisplayed, either because of a valida-

tion error or because the user is opening the page for the first time, or

if the form data should be processed.

209

Validating an All-in-One Form

The All-in-One form uses an if conditional to determine if data has

been submitted from the Web form or if the Web page is being viewed

for the first time. The isset() function can be used to determine if

the $_POST['Submit'] variable has been set (in other words, if the

Submit button has been pressed). The argument that is passed to the

isset() function is the value that was assigned to the control’s name

attribute (name='Submit') in the Web form. The isset() function is

not the inverse of the empty() function, in that a variable can be set to

an “empty” value, such as the empty string (""), 0, NULL, or FALSE. All

of these values will cause the empty() function to return TRUE, because

the variable is set to an empty value, and will also cause the isset()

function to return TRUE, because the variable has been initialized.

If the $_POST['Submit'] variable is set (declared and initialized),

the script will check to see if all required fields are completed and all

responses are valid. If the $_POST['Submit'] variable has not been

declared and initialized, the Web form will be displayed.

if (isset($_POST['Submit'])) {

// Validate the data

The only way

Handling User Input

Processing the Web Form

Once the data submitted by the user has been validated, the second

conditional checks to see if the submitted data passed the validation

process. If all of the validation checks succeeded for the submitted

data (all required data has been entered and in the correct format),

then the data is processed and the user receives a status message.

210

Redisplaying the Web Form

If the submitted data did not pass all of the validation checks, or if the

data has not yet been entered, the All-in-One form will display the

Web form, allowing the user to enter data for the first time or re-enter

data that did not pass validation. As with the two-part form, you

should make the redisplayed form a sticky form, using the else clause

of the second conditional.

if (isset ($_POST['Submit'])) {

// Process the data

To create a simple All-in-One form:

1.

Create a new document in your text editor. Type the

!DOCTYPE declaration, <html> element, header information,

and <body> element. Use the strict DTD and “Number Form”

as the content of the <title> element.

Add the opening and closing tags for the PHP script section

in the body of the document:

<?php

?>

2.

3.

Create and initialize a Boolean variable called $DisplayForm,

which will be used to determine if the Web form should be

redisplayed, and a string variable called $Number:

$DisplayForm = TRUE;

$Number = "";

4.

Add the following code to check whether the form data has

been entered. If it has, the data will be validated:

if (isset($_POST['Submit'])) {

$Number = $_POST['Number'];

echo "<p>You need to enter a numeric

value.</p>\n";

}

}

5.

Add the following code to display the form, including the

entered value for the number field. Note the use of advanced

embedding of XHTML.

if ($DisplayForm) {

?>

<form name="NumberForm" action="NumberForm.php"

method="post">

You could also

211

6.

Add an else clause to use the form data once it is entered

correctly, as follows:

else {

echo "<p>Thank you for entering a number.</p>\n";

7.

Save the document as NumberForm.php in the Chapter

directory for Chapter 4 and upload the document to the

server.

Open the Number Form page in the Web browser by enter-

ing the following URL: http://<yourserver>/PHP_Projects/

Chapter.04/Chapter/NumberForm.php. You should see the

form shown in Figure 4-10.

8.

Figure 4-10

The NumberForm.php form when first opened

Handling User Input

9.

Enter a non-numeric value and click the submit button. The

form should reopen with an error message and the value

you entered in the text control. When you try again with a

numeric value, you should see the “Thank you” message.

10. Close your Web browser window.

212

Short Quiz

1.

2.

Describe the structure of an All-in-One form.

How would a form handler determine if the Submit button

has been pressed?

What family of functions can check whether a user entered a

number in a field on a Web form?

3.

Displaying Dynamic Content Based

on a URL Token

Unlike the post method, which is ideal for working with forms, the

get method is ideal for embedding options in a hyperlink. By passing

URL tokens to a PHP script, many different types of information can

be displayed from the same script. By using a Web page template with

static sections and a dynamic content section, a single PHP script

can produce the same content as multiple static XHTML pages. Web

page templates have an additional advantage of giving all of the pages

a consistent user interface.

Using a Web Page Template

The structure of a PHP-powered Web site is often developed using

a template—a single Web page that is divided into sections. As an

example, Figure 4-11 shows the layout of a Web page template with

the following sections: Header, Button Navigation, Dynamic Content,

and Footer.

213

Figure 4-11

A sample Web page template page layout

You learned in Chapter 2 that when you insert the contents of an

include file in a PHP script, the content of the XHTML document is

displayed in the browser. The following code would insert the con-

tents of the inc_header.php file in the header section:

<?php include("inc_header.php") ?>

If you had 50 individual pages in your Web site and the same header,

button navigation, and footer on each page, and you needed to add

another e-mail address to the header content on each page, you would

have to make the addition on all 50 pages. Using a Web page template,

you could make the change only once—in the inc_header.php file

for the previous example. The header, button navigation, and footer

sections are static because the content does not change unless you

modify the include file. When a user navigates within a Web site that

uses static XHTML pages, a new page with a new header, footer, and

button navigation is opened each time. With Web page templates, the

content of the dynamic section will change but the content and layout

of the static sections will not.

Handling User Input

Navigating within a Web Page Template

You can navigate within a Web page template using hyperlinks and

buttons, just as you can within the pages of a static XHTML Web site.

There are some minor differences, which are explained in this section.

214

Form image

There are

Using Text Hyperlinks for Navigation

When using text hyperlinks to navigate within a Web page tem-

plate, the values that specify which dynamic content to show must

be appended to the filename in the “href ” attribute of the anchor

tag. You use the notation for the get method discussed earlier in this

chapter, with a question mark between the URL and the name/value

pairs, an ampersand between name/value pairs, and an equal sign

between the name and the value.

The following XHTML code creates a text hyperlink that replaces

the current include file that displays in the dynamic data section. In

this example, only one name/value pair is being passed, so there is

no need for the ampersand. The name being passed in the example is

“page”, and the value of “page” is “home_page”. The index.php script

<a href="index.php?page=home_page">Home</a>

Using Form Image Buttons for Navigation

The following XHTML code is inserted between an opening and clos-

ing <form> tag in the section in which you want the buttons to dis-

play. Each button requires a unique value for the name attribute.

<input type="image" src="home.jpg" name="home"

style="border:0" alt="Home" />

In the preceding example, the $_GET or $_POST array would have two

elements for this button: “home_x” and “home_y”.

Displaying the Dynamic Content

Code inserted in the dynamic data section of the index.php file deter-

mines which include file to display in the dynamic data section when

a user clicks a button or activates a hyperlink. Throughout this chap-

ter, you have used the $_GET and $_POST autoglobals, which store the

submitted form values in an array. The $_REQUEST autoglobal can be

used to access the result from form data sent with either the get or post

methods. The following code, keyed in the dynamic data section of the

index.php file, processes the information submitted with either method:

$displayContents = $_REQUEST["page"];

To create a simple Web page template:

1.

Create a new file in your editor as follows and save it as

inc_header.html in the Chapter directory for Chapter 4:

<h1 style="text-align: center">Sample Web Template</h1>

2.

Create a new file in your editor as follows and save it as

inc_footer.php in the Chapter directory for Chapter 4:

<p>Today's Date: <?php echo date('r'); ?></p>

215

3.

Create a new file in your editor as follows and save it as

inc_home.html in the Chapter directory for Chapter 4:

<h2>Home Page</h2>

<p>This is the default home page that displays

whenever a new visitor comes to the site</p>

4.

Create a new file in your editor as follows and save it as

inc_about.html in the Chapter directory for Chapter 4:

<h2>About Me</h2>

<p>This is the page that tells about me and my Web

site.</p>

5.

Create a new file in your editor as follows and save it as

inc_contact.html in the Chapter directory for Chapter 4:

<h2>Contact Me</h2>

<p>This is the page where people can use a Web form

to send me an e-mail.</p>

6.

Create a new file in your editor as follows and save it as

inc_buttonnav.html in the Chapter directory for Chapter 4:

<form action="WebTemplate.php" method="get">

<input type="submit" name="content" value="Home" /><br />

<input type="submit" name="content" value="About Me"

/><br />

<input type="submit" name="content" value="Contact

Me" /><br />

</form>

7.

Create a new document in your text editor. Type the

!DOCTYPE declaration, <html> element, header information,

and <body> element. Use the strict DTD and “Web Template”

as the content of the <title> element.

Handling User Input

8.

Add the following code to the body of the document:

<?php include ("inc_header.html"); ?>

<div style = "width:20%; text-align:center; float:left">

<?php include ("inc_buttonnav.html"); ?>

</div>

<!-- Start of Dynamic Content section -->

<?php

?>

<!-- End of Dynamic Content section -->

<?php include ("inc_footer.php"); ?>

216

9.

Locate the PHP script section within the “Dynamic Content”

section, which is where the button input will be processed to

determine which content page to display. Add the following

PHP code within the block:

if (isset($_GET['content'])) {

switch ($_GET['content']) {

10. Save the file as WebTemplate.php in the Chapter folder for

Chapter 4 and upload the file to the Web server.

11. Open WebTemplate.php in a Web browser by entering

the following URL: http://<yourserver>/PHP_Projects/

Chapter.04/Chapter/WebTemplate.php. It should appear as

shown in Figure 4-12.

217

Figure 4-12

The Web page template script output

12. Click the buttons in the button navigation bar. The content in

the dynamic content section changes to reflect the selected

button.

13. Close your Web browser window.

In the preceding example, the buttons were all named “content”. If

text hyperlinks are added, the same name can be used as the name in

the name/value pair, and the same code can process both. If you need

more buttons or text hyperlinks, simply use the name “content” and a

different value, and add that value as a case in the switch statement.

<a href="WebTemplate.php?content=Home">Home Page</a>

Short Quiz

1.

Explain the purpose of using a Web page template for Web

site development.

Describe the notation for the get method used with a text

hyperlink to target dynamic content to a section of a Web

page template.

What autoglobal can be used to access the values of both the

get and the post methods?

2.

3.

Handling User Input

Summing Up

218

• PHP includes various predefined global arrays, called autoglobals

• Web forms are standard XHTML Web pages with interactive

• The

• The

• Web forms may have two components: the data entry form page

• Magic quotes may be enabled for a PHP server. If enabled, the

• The

• The first step in processing form data is to validate the input.

• The

• The

• Regular expressions determine if an entered string value is format-

• The user should be notified at the same time of all errors in the val-

• Sticky forms are forms that are redisplayed if any errors are found

• Advanced escaping from XHTML is a convenient way to display