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PHP vs. CFML PHP is a server platform and a scripting language. The scripting language contains many useful built-in functions that enable your pages to display dynamic content. If you have developed with the PHP scripting language, you'll find that the ColdFusion language (ColdFusion Markup Language, or CFML) is quite a bit different, but also similar in many ways. First of all, ColdFusion objects (tags) are all inherently active. In ColdFusion, the tag takes care of the creation and the cleanup. When the tag is placed on a page, it is instantiated by the ColdFusion server. The server takes care of the cleanup as well. This differs from PHP. When developing in PHP, you must create an instance of an object, use the object, and then later destroy the object. For example, when working with a recordset in PHP, you first create the connection and the recordset:
$connMysqlbookstore = mysql_pconnect("tom", "tom", "mypassword") or
die(mysql_error());
mysql_select_db("bookstore", $connMysqlbookstore);
$query_rsGetOrders = "SELECT CustomerID, OrderDate FROM Orders";
$rsGetOrders = mysql_query($query_rsGetOrders, $connMysqlbookstore)
or die(mysql_error());
$row_rsGetOrders = mysql_fetch_assoc($rsGetOrders);
$totalRows_rsGetOrders = mysql_num_rows($rsGetOrders);
?>
Next, you must use the recordset on a page by manually looping through your recordset:And finally, if you are done with the recordset, you must free the results and close the connection: mysql_free_result($rsGetOrders);
mysql_close($connMysqlbookstore);
?> When doing the same thing in ColdFusion, remember that the ColdFusion tags are the equivalent of a server-side object in PHP. A
This code creates the recordset. Once it's created, all you have to do is display it. Looping is built into the ColdFusion tags as well, so it's not necessary to manually start or stop the loop. You can simply output the results with a
The ColdFusion code has several advantages that are evident right from the start: it's shorter and more concise. It's also much easier to understand exactly what the code does, even without programming knowledge. Another advantage is that cleanup code isn't required—you don't have to destroy your objects. The server handles those details. Yet another advantage, that may not be apparent from the code, is that you can use this recordset again and again on the same page. You avoid having to reset your pointers as you would in PHP using a mysql_data_seek() or a similar construct. Another thing you'll notice from the code is that the database MySQL is specified. The PHP code will not work with any other database. You can't simply upgrade your database to MS SQL Server—because the code will not work. You can use a database abstraction layer in PHP to simplify the database communication, but that involves learning another set of rules and more syntax. With ColdFusion, all databases are handled the same way by Using less code Less code = less typing = more time for programming the meat of your program. Now you don't need to spend as much time on the mundane aspects like the object creation, keeping track of your loops, and the closing and releasing of objects. ColdFusion simplifies these tasks across the board. Take another example, which demonstrates a common web programming task: sending an e-mail. The e-mail functionality of PHP is built-in, as it is in ColdFusion. However, the syntax is not as intuitive and the code required is more verbose. Note that in both the ColdFusion and PHP examples, we assume that the administrator of the application server has set up the mail server properly: $to = $_GET ["txt_tofield"];
// set the to field from an incoming form field
$subject = "Your order confirmation number is: ";
$subject .= $_SESSION_["order_number"];
$message = join("",file("message.txt"));
$from = "From: Admin In the example above, notice that the body of the message is included as a separate file (message.txt). The message body could have easily have been hard-coded into the program, but with ColdFusion, using include files can be very beneficial. An include file in ColdFusion is read and interpreted as though it were part of the page, so it is a simple process to add a text file to the body of an e-mail message. In PHP, you have to read the file into an array and then join the array. Newer versions of PHP will include better file handling, however. In ColdFusion, these include files can be conditional. In other words, you can access different include files based on criteria that you establish, such as a value in a field from the database. For example, inside the message.cfm page, you might have code that looks like this: Built-in functionality One thing that will become apparent after you've coded a couple of ColdFusion sites—much of the same functionality that is built into PHP, or offered as additional modules that you can utilize, is also built right into the ColdFusion language using the tag-based syntax. A few of the more powerful ColdFusion tags (some of them new to ColdFusion MX) are: | ||||||||||||||||||
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New features in ColdFusion MX ColdFusion MX is a new release of a die-hard product that has been completely redesigned from the ground up. This version of ColdFusion is Java-based, but works almost entirely like the previous versions of ColdFusion. ColdFusion tags—with very few exceptions—work in exactly the same manner as described in this article. In fact, most applications created in previous versions of ColdFusion will run without modification. One of the biggest new developments in ColdFusion MX is that you can use JSP tag libraries with your ColdFusion pages. This means that a ColdFusion programmer can take advantage of any existing tag libraries, as well as create new ones. This is in addition to all of the ColdFusion tags and COM objects that are already in a ColdFusion programmer's arsenal. Another new, big feature in ColdFusion MX is ColdFusion Components (CFCs). CFCs are self-documenting and self-contained. You can use CFCs through any ColdFusion pages on the ColdFusion server. Other technologies can access your ColdFusion components if you publish them as web services (for instance, a Macromedia Flash application may use a ColdFusion component to run a database query based on a user's request). Create CFCs with the cfcomponent tag, and save them with a CFC extension. Include your CFML logic (such as a cfquery tag, conditional code, and so forth) within a cffunction tag inside of the cfcomponent tag inside the CFC file. Then, any ColdFusion page on your server can call the functions (also called methods) within the CFC. For full details on how to use CFCs, refer to the other articles in the ColdFusion MX Application Developer Center, and to the ColdFusion MX documentation book, Developing ColdFusion MX Applications. Developing ColdFusion components that produce web services has one major advantage over producing web services in other technologies—you can create a ColdFusion component web service with standard CFML code in a fraction of the time. Simply add the attribute access="remote" to the cffunction tag to activate the CFC as a web service. The following is a simple CFC that reads the contents of a directory and returns a list of JPEG files in that directory: XML parsing Also, ColdFusion MX has XML parsing built into the language as well. A new tag in ColdFusion MX is the ColdFusion MX allows you to address the XML construct as a structure, using dot notation. Assuming that the preceding XML structure is contained in a string variable named books, the following code pulls apart the structure created by the XML tags and sets variables to hold the data: Note that the xmltext method will retrieve the text within the XML tags. To display the variables on the page, you can use simple CFOUTPUT tags: Book Title: #bookTitle# ISBN: #bookIsbn# URL: #bookUrl# ColdFusion stores XML internally as a structure, so a simple That one tag will show the following display in your browser: Figure 1: A CFDUMP tag will display the XML structure on your web page Session Management Both ColdFusion and PHP have session management, but if you've ever had to build an application that utilized PHP's built-in session management, you know the limitations. PHP uses the file system to handle sessions, which is slow and lacks flexibility. Also, the PHP session files are left behind in the sessiondata directory. There are third-party libraries (like PHPLib) to manage database-based sessions, but PHP itself doesn't have a mechanism to handle sessions inside a cluster. More in general, PHP doesn't have any out of the box clustering capability. ColdFusion was built for scaling. ColdFusion has a sophisticated session-handling mechanism that works even if the user has cookies turned off. Session state is maintained in server memory using a unique identifier, and this can be passed from page to page if you determine that the user has turned off cookies. This makes for a more user-friendly web experience, allowing information to be maintained easily across pages. | ||||||||||||||||||
Summary PHP is certainly a viable technology to build Web applications, but for PHP programmers who wish to make the change to ColdFusion, the transition can be an easy one. You'll find that applications that once took days can be done in hours, and calls to third-party modules can be a thing of the past. CFML is a versatile language that is self-contained, easy-to-learn, and promotes rapid application development. Also, with the new additions of JSP tag libraries, ColdFusion Components, XML functionality, and web services in ColdFusion MX, ColdFusion is more versatile than ever before. | ||||||||||||||||||
| About the author Tom Muck is co-author of five Dreamweaver-related books including the bestseller, Dreamweaver UltraDev4: The Complete Reference, and its successor Dreamweaver MX, The Complete Reference. He is an extensibility expert focused on the integration of Macromedia products with ColdFusion and other languages, applications, and technologies. Tom has been recognized for this expertise as the 2000 recipient of Macromedia's Best UltraDev Extension Award. He also authors articles and speaks at conferences on this and related subjects. As Senior Applications Developer for Integram in Northern Virginia, Tom develops back-end applications for expedited, electronic communications. Tom also runs the Basic-UltraDev site with co-author Ray West and is an advisor for MX inSite magazine. |
Thursday, January 21, 2010
1/21/2010 11:24:00 AM
MrZam
Infotech
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