Whether you are actually coding in PHP or simply using other people’s PHP code in your pages, it is helpful to understand a bit about PHP syntax and how PHP programs are structured. Like ASP code, PHP is embedded directly into a Web page and requires special tags (called delimiters) to let PHP know what can be output directly and what needs to be handled by the PHP interpreter.

PHP code can be delimited in several different ways. The first is through the use of the <script> tag:

<script language="php">
echo "Welcome to PHP!
";
</script>

This method can cause problems with some HTML authoring tools because the content between the script tags is not recognizable as HTML content. Therefore, this method has been deprecated, although it can be found in older PHP pages.

The recommended syntax for PHP is to use <?php ?> instead. This syntax is referred to as full tags. For example:

<?php
echo "Welcome to PHP!
";
?>

In some cases, you might find PHP documents using a shorter version of this syntax referred to as short tags. For example:

<? echo "Welcome to PHP!
"; ?>

You might even find them using ASP-style tags:

<% echo "Welcome to PHP!
"; %>

Use of short tags is optional and may be disabled on a particular Web host. Sticking with full tags is the best option for code portability.

Like JavaScript and other languages that share a C-like syntax, PHP code is case sensitive. Statement lines are followed with a semicolon, as you can see with the various echo statements listed previously.

/* C style */

// C++/Java style

# Perl style

<?php
$first_name = 'John';
$last_name = 'Doe';
$age = 33;
echo "name: $last_name, $first_name  age: $age
";
?>

name: Doe, John  age: 33

<?php
// JavaScript-style 'if' statement
if ($user_role == "administrator") {
    echo "administrator login successful.
";
}
else {
    echo "user login successful.
";
}

// Alternative style 'if' statement
If (%user_role == "administrator") :
    echo "administrator login successful.
";
else :
    echo "user login successful.
";
endif;
?>

<php? if (%user_role == "administrator") : ?>
   <br />
   <span>administrator login successful</span>
   <br />
<php? else : ?>
   <br />
   <span>user login successful</span>
   <br />
<php? endif; ?>

<?php
function initialize ()
{
    echo "initializing...
";
}

echo "calling initialize
";
initialize();
echo "initialization complete
";
?>

To use FastCGI, you must have IIS 7 for Windows Vista SP1 or later or Windows Server 2008. Because IIS is not part of the default installation for either operating system, you will have to add it yourself.

At the time of this writing, PHP version 5.2.5 is the current release of PHP, and it can be downloaded from http://www.php.net/downloads.php. This download page is shown in Figure 35.3. The nonthread-safe binaries (NTS) are preferred for use with FastCGI and will perform better. Don’t download the installer version because it is not necessary when using FastCGI. Simply download the Windows binaries zip file.

Figure 35.3. Download the most recent version of PHP directly from www.php.net.

If you need to use an older version of PHP for a particular application, you can use FastCGI with versions 4.4 and higher. Versions 5.2.3 and higher, however, include optimizations that will allow better performance when running on Windows with FastCGI.

When the download is complete, extract the contents of the zip file to C:PHP. Then, in that folder, rename the file php.ini-recommended to php.ini.

After you have IIS 7 and PHP installed, you need to tell IIS where it can find the PHP installation and which file extensions to use for it. This is done in the IIS Manager, and this configuration process is the same for Vista SP1 and Windows Server 2008. Follow these steps to enable PHP using FastCGI:

Even if you have IIS7 installed and configured to use PHP, Expression Web 2 will not use it by default when you preview in the browser. Instead, it will use the Microsoft Expression Development Server. You either need to configure the Web site you just created to use IIS for the preview, or tell the Microsoft Expression Development Server where to find your PHP CGI executables. Fortunately, both of these configuration options are done in the same place in the Site Settings dialog. Follow these steps to configure the preview of PHP pages using the Microsoft Expression Development Server:

If you’d rather configure the preview feature to use IIS running locally instead, follow these steps:

Note

If you get an error when previewing your page, or if your PHP code doesn’t execute as you expect, see “PHP Code Doesn’t Seem to Execute When I Preview It in the Browser” in the “Troubleshooting” section of this chapter for possible solutions.

Syntax highlighting makes it easier to edit in Code View because it makes code blocks and the elements contained in them stand out from the surrounding code. With syntax highlighting, you can customize each PHP item with the color of your choice. You can customize foreground and background colors and even set font styles such as bold, italic, or underline specifically for each PHP item.

Expression Web 2 is configured with default values for each of the formatting options. (You can change them if you don’t like the defaults.) Follow these steps to configure syntax highlighting for PHP elements:

IntelliSense is a feature of Microsoft’s code editors that helps you speed up coding by giving you options to select code from a list as you type. IntelliSense will also provide you with tooltips to fill in parameters for function calls. IntelliSense works inside a PHP script block regardless of the type of PHP tags you use to identify the block (<?php ?>, <? ?>, or <script language="php"> </script>).

Press Ctrl+L inside a PHP script block to bring up a list of available PHP functions, as shown in Figure 35.12. You can quickly locate a function from the long list by typing one or more letters of the function name right before or after you activate the list. Alternatively, simply scroll down the list using the mouse or the arrow keys and choose a function manually.

Figure 35.12. IntelliSense for PHP makes it easy to discover PHP techniques and makes entering PHP code faster.

When the function you want to add is highlighted in the list, you can enter it in the editor simply by pressing Tab.

If the selected code is a function, IntelliSense will show you a tooltip with the parameters required by the function when you enter the left parenthesis, as shown in Figure 35.13. As you enter parameters and type the comma separating them, the next parameter to enter will appear bolded in the tooltip.

Figure 35.13. Tooltips guide you through the process of entering parameters for function calls.

Global variables in PHP are provided by the environment and include several collections, such as session variables, form elements, cookies, and environment variables. IntelliSense can simplify the addition of global variables in your code as well. In PHP, global variables are preceded by a $_. If you type those characters into the editor inside a PHP code block, IntelliSense will present you with a list of global variables, as shown in Figure 35.14. As with the function list, you can type a partial name and then press Tab to complete the entry.

Figure 35.14. You can choose from a list of global variables when you enter the $_ prefix.

If you prefer not to use IntelliSense, or want only some of the IntelliSense features, you can enable or disable them in the Page Editor Options dialog box.

The following are some PHP IntelliSense options you can enable or disable:

Follow these steps to set IntelliSense options:

The Form variable holds information passed to the page from form elements on the requesting page. Form variables are passed using the HTTP POST method; therefore, the global variable name is $_POST.

The following code is inserted into a page when you choose this option:

<?php $_POST[]; ?>

To reference a specific form variable, you must use the name of the form element as a key, as shown in this example:

<?php $_POST["LAST_NAME"]; ?>

The URL Variable item inserts a script to pull items passed to the page via the HTTP GET method as parameters passed in the calling URL. The following script is inserted:

<?php $_GET[]; ?>

As with other global variables, you must use the name of a URL variable as a key to reference a specific variable value.

As a user visits pages on your Web site, the browser passes a session value that the Web server uses to identify the specific user session. Session variables can be used to maintain user state information on the server between page requests. Use the Session Variable script item to insert the following script:

<?php $_SESSION[]; ?>

Instead of having session values determined by the requesting page, you must store values in the session variable yourself. Store it using a key that you create:

<?php $_SESSION["role"] = "administrator"; ?>

Then, on a subsequent page request, retrieve it using the same key:

<?php
if ($_SESSION["role"] == "administrator") {
    echo "administrator is logged in.
";
}
?>

Session variables last only as long as the user’s session is active.

Cookie variables are similar to session variables in that they store information that persists from page to page. Cookies, however, are sent to the browser and stored on the client computer instead of the server. This item inserts the following script:

<?php $_COOKIE[]; ?>

PHP code that will be used in many pages can be separated out and put in its own file, which then can be included in a PHP page using the include statement.

When you choose the Include item from the Insert menu, you will be prompted to choose a PHP file to include, as shown in Figure 35.17. This item inserts the following script, with the chosen page as a parameter to the include statement:

<?php include('common.php'), ?>

Figure 35.17. Include files let you keep shared PHP code in one place.

The Include Once script is similar to the Include script, except that the inserted script will be included in a page only once to avoid variable and function redefinitions, value reassignments, and other potential problems. When you choose this item, the following script is inserted:

<?php include_once('common.php'), ?>

As with Include, you choose the file to add to the statement.

The PHP require statement is similar to the include statement, except in the way in which errors are handled when it is used. If the file referenced by an include statement doesn’t exist, an error message will be displayed but script execution will continue. When the require statement is used, PHP script execution will stop if there is an error with the included file.

The following script is inserted when this statement is used:

<?php require('common.php'), ?>

The require_once statement is analogous to the include_once statement, but with the same difference in error handling as between include and require. This script segment is inserted:

<?php require_once('common.php'), ?>

The Code Block item inserts a simple empty PHP script block tag, as follows:

<?php ?>

This can be useful as shorthand for entering the tag quickly, particularly if you memorize the keyboard shortcut used to enter it: Alt+I, H, B.

As mentioned at the beginning of this chapter, the echo statement is a very common way to have the PHP script insert dynamic text into a page. This item inserts the following script:

<?php echo ?>

The cursor is positioned after the echo statement to facilitate adding the string or variable values to be echoed.

The Comment item inserts a PHP C-style comment into the program flow, with the cursor positioned to type the comment text:

/* */

Note that this script doesn’t include the surrounding script block tags. PHP assumes that the comment will be inserted into an existing block.

The if statement is a commonly used conditional execution statement. This item inserts the following script:

<?php if ?>

An expression to evaluate is then inserted enclosed in parentheses. The following is an example:

<?php if ($user_role == "administrator") ?>

An if statement typically is followed by a block of code to be executed, contained in braces. The code between the braces is executed only if the expression evaluated by the if statement is true. Note that this script does not add the braces; they must be added by hand.

The if statement can also use the alternative style described earlier in this chapter, in which case you must manually enter a colon after the expression to be evaluated, as well as a corresponding endif; statement. This can be useful when you want to embed HTML code in the if block, as the example in the “PHP Program Flow” section of this chapter shows.

The else statement can be used to follow up an if statement as an alternative block of code to execute if the expression evaluated by the if statement is false. This item inserts the following script:

<?php else ?>

The else statement should be followed up with a block of code in curly braces. You can also use the alternative syntax, although you will need to remember to add a colon after the else statement. An example shown earlier in the chapter in the use of the if..else..endif syntax is repeated here to demonstrate this:

<php? if (%user_role == "administrator") : ?>
   <br />
   <span>administrator login successful</span>
   <br />
<php? else : ?>
   <br />
   <span>user login successful</span>
   <br />
<php? endif; ?>

My PHP code isn’t executing when I preview the page in the browser; instead, the PHP code appears in the page source just as it is in Expression Web 2.

If FastCGI or PHP isn’t configured correctly, IIS won’t know how or won’t be able to parse the PHP code in your page. PHP pages must be processed by the php-cgi engine to display correctly.

To resolve this problem, check the settings for the FastCgiModule configuration in the IIS Manager. Pay particular attention to the module, request path, and executable entered for the FastCgiModule mapping.

You also should verify that PHP itself is configured correctly. You can do this from the command line by executing the PHP command-line interpreter (CLI) directly, with the -info parameter. From the command line, type php -info and press Enter. You might have to change directories to the C:php folder first, if it isn’t in your path.

When I attempt to preview a PHP page in the browser, an HTTP Error 500 - Internal Server Error is displayed.

An Internal Server Error (HTTP Error 500) is a generic error pointing to a failure in the Web server or a CGI program. This problem usually is a configuration problem with PHP or with the FastCGI module. If the CGI executable doesn’t exist in the specified path, or if permissions on the PHP directory don’t allow IIS to call the executable, you could receive this error.

IIS uses the NETWORK SERVICE user account to run PHP. This account, or a group that contains it, must have read and execute permissions to the C:php folder. You can give these permissions to the IIS_IUSRS group because it contains the NETWORK SERVICE account. To view or change current permissions, right-click the php folder in Explorer and select Properties. Select the Security tab.

When I attempt to preview a PHP page in the browser, part of the code is displayed in the browser and code execution halts partway through.

This problem generally involves a syntax error with your PHP code. Look for mistyped statements, misnamed function calls, and other problems with your syntax. Improperly nested PHP blocks can also cause problems.

Syntax highlighting can help track down syntax errors. Look for code highlighted yellow to indicate a problem with parsing the code.