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Advanced PHP Programming
from the high-praise dept.
Many of the previous generation of PHP books were fattened with lots of filler: how PHP imports form-submitted variables into its namespace, definitions and examples of valid XML documents, one-line summaries of every PHP function, even an HTML reference. It's like going to Gallagher's Steak House and filling up on free bread. Ladies and gentlemen, may I submit the Atkins-Friendly PHP book. This is not a book about syntax or data structures. This is a book on how to use PHP in enterprise environments. During my first read, I realized around page 126 that I had already learned as much as I had expected to learn and I was just getting started!
The book is very well written, with a friendly tone that is neither pedantic nor partisan. A knowledge of PHP before version 5 is assumed, and the situations tackled are very much from the real world. The focus goes beyond getting what you want to appear in the browser, too; scaling problems of very large web sites, managing a code base with multiple developers, and building your own extensions to PHP are all discussed.
The author draws most examples from a Unix + Apache + PHP environment, and MySQL is the primary database used. The examples are all in PHP5, but many ideas can still be implemented in PHP4. In other words, you can still learn a lot even if you're committed to PHP4 for the near future.
Part I of the book is called Implementation and Development Methodologies (some of these part and chapter names could be a little less clunky, even if they are correct), and the first chapter is about coding style. After that comes a thorough discussion of the new features of PHP5. These are language aspects that are commonplace in other object-oriented languages (e.g., java and python), but which I admittedly knew little about:
- encapsulation: the ability to keep object attributes and methods private or protected;
- static attributes and methods to make class functions or singletons;
- user-definable constructor, destructor, accessor, mutator, and copier functions;
- interfaces, which are like abstract classes. A class can implement one or more of these as well as extend a concrete class;
- exceptions, which allow propagation of errors and warnings back up through the function stack.
Other PHP programming concepts are discussed in this part, such as templating, using the command-line interface, and unit testing. The chapter on Managing the Development Environment includes some CVS basics as well as how to organize and keep separate your development and production environments without breaking what works. Another topic discussed is when to use PEAR classes and when to roll your own.
Part II, Caching, is where the book gets hard-core. Once your application works, how do you optimize its performance and scale it so you can have hundreds of thousands of users?
- You can use static variables to reduce recalculations, and compile your regexps.
- You can cache data on the PHP level in flat files, DBM files, shared memory, or even in user cookies.
- There are also solutions outside of the PHP userspace. The ordinary PHP process takes the text which constitutes the programmer's code and compiles into a assembly-style intermediate code. Then the intermediate code is executed. If a script is executed several times without change, the same intermediate code is created, executed, and thrown away several times. A compiler cache saves this intermediate code and reuses it. The author has developed a free, open-source compiler cache.
- There are also code optimizers, which eliminate dead code and overly-verbose constants.
- Reverse proxies also work in web sites to reduce network latency. Latency occurs when a server is stuck waiting for a request to be completed before it can execute. A reverse proxy server only collects requests, then hands them off on a high-speed network to the actual server.
- This can be made even better with content caching. The proxy can determine if the request requires handling by the PHP webserver at all. If a stale, cached copy suffices, it is served instead.
- Content compression sends your data over the internet compressed. The client's browser is in charge of decompression.
Part III, Distributed Applications, is of big importance to the developer of medium-sized sites. The author discusses the familiar topics of database interaction (including how to troubleshoot your slow queries), authentication, and session handling. Then a chapter on clustering: how to arrange multiple, redundant servers to create a robust, fail-safe system.
The final chapter in this part covers another hot topic: Web Services. Say you want to edit your weblog entries on a real text editor rather than through a web form. If you have RPC (Remote Procedure Calls) set up on your web server, you need only write a script which manufactures a request to a web service and and ships it out. What's the sales rank on Amazon of the book you just wrote? What's the weather like in Medford, Massachusetts today? These are all jobs for web services. XML-RPC and SOAP are approaching the standards state of usage, so using one of these means you don't have to develop your own RPC client or server library. SOAP is even richer than XML-RPC: it's an all-purpose messaging protocol which is in use by many of the big players in web services (e.g., Amazon, Google).
In Part IV, Performance, the author returns to the optimization question. How can PHP scripts themselves be made to run faster? There are several techniques:
- Use the apache benchmarker or other load-generating programs to determine which requests take the most time.
- Use a PHP profiler such as the one the author has written to examine your script line-by-line and determine which function calls are most expensive.
- Use a synthetic benchmarker (such as the one included in PEAR) to analyze small bits of code and discover how efficiently they do their task. Which is faster: interpolation of variables or string concatenation (the latter, at least before PHP 4.3)? If you don't have a library compiled into PHP, can you implement all the functions in userspace efficiently (not really)?
Part V, Extensibility, is for people who want to adapt PHP on the language level for their needs. This part requires a knowledge of C and a strong grip on your hat! After a discussion of PHP and Zend Engine (the virtual machine on which compiled PHP runs) internals, the author shows how to make both simple and complex extensions. You can add new functions to PHP, add a suite of library wrappers, add and manipulate classes and objects, all using pre-defined macros. In the last chapter, you can extend Zend itself to (say) implement all errors as exceptions, create a PHP Shell, an opcode-dumper, or modify the author's compiler cache or profiler.
I very much enjoyed the book. I have chosen to take the plunge into PHP5 for a new web project, partly because this book convinced me it's worth it. I can't imagine I'm going to use everything I've learned from the book, but I'm glad to know how problems like these are solved.
There are a few typos and misspellings, but that's to be expected in such a large book with limited turnaround time. Definitely recommended.
Matthew Leingang is a Preceptor in Mathematics at Harvard University. He continues to try to integrate web development into his day job. You can purchase Advanced PHP Programming: A practical guide to developing large-scale Web sites and applications to PHP5 from bn.com. Slashdot welcomes readers' book reviews. To see your own review here, carefully read the book review guidelines, then visit the submission page.
php-embed (Score:5, Informative)
This is an often-overlooked advantage in PHP: the ability to use php-embed [php.net] to run embedded PHP within another application. For example, our company has created an HL7 HIPAA-accelerator in C/C++; we chose PHP as the embedded language in our product--by which users can create custom data transformations.
The reason? PHP is easy to use, loosely-typed (which is an advantage in our project), fast, and of course, free. It was a great decision.
Re:php-embed (Score:5, Informative)
I've got a couple database applications using PHP that I've been working on for a while - I wasn't aware that PHP could be easily embedded into a C application.
Obviously, I'd get better performance with a hybrid of C and PHP code, so this actually simplifies quite a few projects for me. (No more mixing PHP, Perl, C, Python, MySQL and TCL on a single application - yay!
Thanks for pointing this out..
Parent
Re:php-embed (Score:5, Informative)
Sure. One more thing, the zval integration is easy as pie, something like:
Forgive the poor code above, just the way I remember it... I'll email you the php-embed stuff I have in its entirety.
Parent
Re:php-embed (Score:4, Informative)
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Re:php-embed (Score:3, Interesting)
Just on a guess, I'd say there are a lot more PHP developers out there than Lua or Ruby developers (though Lua looks pretty cool). Besides, Ruby developers are all just ex-Pythoneers who thought Python [python.org] was becoming too popular, and don't really count as developers anyway ;>)
Re:php-embed--troll/rant (Score:2)
OK, I'll byte. (1) Database access from a website. (2) Form manipulation. Name one other language or system where it's easier to dynamically create a set of html pages with data extracted from a database. Or a language where it's easier to get and use data from a form filled by the user.
Re:php-embed--troll/rant (Score:3, Interesting)
PHP's far from best-of-class in any of these respects in my experience; only pervasiveness is in it's favour, and running my own servers, that isn't
Re:php-embed (Score:5, Interesting)
Parent
most of the books (Score:5, Interesting)
Things like php-ncurses and php-gtk or even how to properly debug cli apps and it is strange saying there is a large following of PHP commandline (cli) people out there.
Anyway, always good to see more books at any rate.
Re:most of the books (Score:2, Interesting)
i wrote an encrypted chat client/server combo using php exclusively with ncurses and sockets
source is here [phism.org]
it's a bit hard to setup, because it was just a for phun project... man php is great
Re:most of the books (Score:2)
And don't forget ActivePHP which is a neat little deal for scripting nice little windows based php apps.
Latest software (Score:5, Interesting)
I've got a bit of a complaint about computer books, in that they frequently concentrate on the latest and greatest versions and brush aside the older versions - the versions that the majority of web hosts might be running, for instance.
I was looking for a MySQL book a while back, and there were dozens of them on the shelves in the bookshop, but all based around MySQL 4 - not the ubiquitous MySQL 3 that I was trying to learn. Looking through at all the new features can be a bit dispiriting, especially when you're stuck with the older version.
Anyone else had similar problems?
Re:Latest software (Score:5, Insightful)
Parent
Re:Latest software (Score:3, Insightful)
I know what you're talking about, and you're right: new books are about new software.
Your point about web hosts is also true; it's difficult to find a PHP5 webhost. It takes guts to run a RC on production servers! However, you can be certain that soon enough PHP5 will become as ubiquitous as 4.
Anyways, just judging by the review, it seems like this book's intended readers are enterprise programmers: people who will leverage more control over their development platform than the average webmaster.
Re:Latest software (Score:2)
There are hosting companies that still host PHP3? PHP4 has been out for like FOUR YEARS now...
I admin my own systems, so I'll be moving to PHP5 as soon after its official release as I can do some regression testing.
The built-in SQLite is very much reason enough to begin using it with my PHP-GTK based applications!
Mysql + Apache 1.x (Score:5, Insightful)
Apache2? (Score:2, Informative)
-Phantom
Re: Against Apache 2.x? (Score:5, Insightful)
- PHP developers are not opposed to Apache 2.x.
- PHP is stable on Apache 1.3 _AND_ 2.x.
- Apache 2.x has a large number of new features designed to better handle high volume sites (with or without PHP)
MySQL is still the standard web-hosting provider database backend, that is why most books cover it. mySQL is very similar to other SQL dialects. If you understand SQL, PostgreSQL is easy and you shouldn't need explanation on how to run queries from PHP. The books focus on PHP, not the SQL languages... if you want to learn about SQL, get a SQL book.
Parent
Re: Against Apache 2.x? (Score:4, Informative)
You ought to be using PEAR's DB [php.net] class anyway, which abstracts away most of the differences in dialect.
Parent
Re: Against Apache 2.x? (Score:2)
> new features designed to better handle
> high volume sites (with or without PHP)
Yup. We run Apache 2.0 with mod_jk and mod_php on SemWebCentral [semwebcentral.org];, no problems.
Re: Against Apache 2.x? (Score:3, Informative)
Re:Mysql + Apache 1.x (Score:3, Insightful)
Re:Mysql + Apache 1.x (Score:4, Interesting)
Sigh, I really wish these books would get with the times and start using SQL Server 2000 (or even Oracle), and Microsoft IIS
I'm a firm believer of using the right tool for the right job. Some projects I've worked on don't really need foreign key enforcement, and subqueries, and what not provided by PostgreSQL. MySQL has worked just fine in a lot of cases. Some industrial strength applications may need a PostgreSQL. But whatever makes the most sense should be used.
Parent
Re:Mysql + Apache 1.x (Score:3, Insightful)
So really, it's not so much that we need more Firebird/Postgresql in books because they're better, it's to make sure that the audience gets a bit of everything. MySQL might be seen as a "teaching database
Re:Mysql + Apache 1.x (Score:3, Interesting)
MySQL not supporting foreign keys is just fine. I just wish it would stop PRETENDING to support them by parsing and subsequently IGNORING foreign key declarations.
MySQL's documentation has typically heaped scorn on everything they didn't implement that version, then the attitude suddenly disappears when they do get around to implementing it. It strikes me as an astonishingly un
Re:Mysql + Apache 1.x (Score:5, Informative)
I've been using 2.x for about a year. Zero problems. Performs great.
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Re:Mysql + Apache 1.x (Score:2, Interesting)
mysql always seemed to me to be a real amateurish production, while pgsql seemed more professional. That's just interpretation, however, and may be influenced by the fact that every half-assed Perl hackery uses mysql as its backend. Guilt by association, I suppose.
If I were doing something that n
Re:Mysql + Apache 1.x (Score:5, Informative)
I used to think that, until I realized that my programs were twice as complicated as they needed to be due to MySQL's lack of typical relational database functionality. Triggers, views, sub-selects, user-defined functions, transactions, templates... the list of PostgreSQL advantages (feature-wise) over MySQL is long.
MySQL is now trying to catch up to PostgreSQL in the feature category, but is still not even close. That's not to say that MySQL is worthless -- quite the contrary: if you want an indexed file system, MySQL is the way to go. On the other hand, if you want a good, open-source relational database, PostgreSQL is a champ.
Ease of use pushed us away even before we looked at benchmarks, which are all triumphantly in MySQL's favor.
PostgreSQL is a bit harder to initially set up, when compared to MySQL. On the other hand, it isn't rocket science; it is still pretty simple.
In terms of benchmarks, you might want to notice that MySQL is hardly "triumpantly" winning normal benchmarks. Take a typical MySQL table (MyISAM) and try doing lots of concurrent reads and writes. You'll find that MySQL's habit of locking the entire table on writes really is a downer when it comes to performance.
Another thing to note is that MySQL has placed their libraries under the GPL, making them somewhat incompatible with the PHP license. This has caused a bit of a rift in the PHP community, with the result being that MySQL will probably be less supported by the PHP developers while PostgreSQL increases in support.
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Re:Mysql + Apache 1.x (Score:3, Informative)
> relational database, PostgreSQL is a champ.
Right on. Good utilities [postgresql.org] are available for it, too!
Re:Mysql + Apache 1.x (Score:2)
Re:Mysql + Apache 1.x (Score:5, Informative)
Locking issues cause MySQL to slow down greatly when the database is shared between readers and writers. In fact, any significant amount of concurrent write traffic has, IME, always caused MySQL to deadlock.
My own testing showed that MySQL, on a dual P4-2.4 with PHP could deliver about 630 pages/second with 1 very simple query per page. PostgreSQL delivered 480 pages/second with the same page. This is MySQL's optimum environment and it only beat PostgreSQL by 31%. Certainly something to consider, but hardly earth shattering.
Since PostgreSQL is so much more capable in every other way, it wasn't hard to decide to move everything to PostgreSQL.
Parent
I still remember (Score:2, Funny)
Re:I still remember (Score:3, Funny)
I couldn't find an Onion link to this story, but it is on a number of other sites.
Here's a link [bbspot.com] to one.
"Advanced" PHP ? (Score:5, Funny)
Re:"Advanced" PHP ? (Score:2, Funny)
Advanced PHP (Score:3, Interesting)
Maybe around 5.3 (Score:2, Interesting)
Don't get me wrong I love the current state of PHP for developing small fast websites. But if hi
Quit your elitist bitching (Score:5, Insightful)
There are times when to use a strongly-typed, "true" OO language like Java or C++ and times to use a scripting language like PHP or Perl. Part of being a good programmer is being smart enough to use the right tool for the right job. If you want to torment yourself by over-engineering a small- or mid-sized website in EJB, go for it, but respect those who like being able to get stuff up quickly and easily, with a minimal learning curve. And YES, it is possible to build secure web apps in PHP, despite what you may have heard.
When you've only got a hammer, everything looks like a nail.
Aw, Crap (Score:2, Insightful)
(I know what it means, but what is it doing here?)
Language Bashing (Score:4, Insightful)
The issue is not weather PERL or PHP or C is better than the other.
Languages are just tools. Writing good software is a reflection of one's ability to plan, use OOP, and troubleshoot code, just to name a few.
When faced with a problem that needs solved, you examine the problem, and select the most appropriate tool(language) to get the job done, and hopefully you apply good software writing skills to the solution.
Even if you think PERL or something is so much better than PHP, but you suck at writing good software, your software is going to suck.
I have a problem with PHP's scope (Score:5, Insightful)
PHP5 is impressive, but it appears to be trying to change its scope and here is why. Like Bash, PHP is a big time saver for small programs, but is more difficult to write and maintain as the program gets larger and more complex. The features added to PHP5 will let it scale better, but it will lose its Bash-like advantages. It is trying to move into the arena with Java, ASP.Net(?Maybe), Python, Ruby,
After seeing MY limits with PHP I moved to Python although I still use PHP for simple web scripts. In my opinion, PHP5 is a new language in an old arena. You should choose the right tool for the job, and if you need the new features in PHP, have a look at a powerful, weathered language like Java, Python, or Ruby, or (add your language here).
Re:I have a problem with PHP's scope (Score:2, Insightful)
For purely procedural code, PHP5 is EXACTLY the same as PHP4. The only changes have been in object-oriented side of things. And even most of those changes are optional.
Furthermore, the OO changes to PHP5 bring it in-line with other languages. Ultimately it should make it easier for developers familiar with OO programming to get into PHP.
I enjoyed this book (Score:4, Informative)
I bought this book near the beginning of my current adventure and I learned a lot from it. It's not the typical PHP book that just mirrors the php doc web site. There's a lot of great information in there. I'm still on PHP4 but that doesnt matter, the concepts still apply.
Thumbs up!
Good for SysAdmins too! (Score:5, Informative)
To borrow a phrase, "in a nutshell", this book is excellent! Some of it is beyond my skills at the moment, but I appreciate every bit. The author covers OO in a way that I understood, and presented real-world solutions that helped me understand. But, IMO, the best part isn't the PHP, it's the operational theory -- the real problems that sysadmins and web programmers face with large websites, caching, load-balancing, scalability. This made the book worth the $80CND I paid for it.
I highly recommend it!
-- Steve.
But how to decide? (Score:2)
Or I'm just thouroughly confused.
Making fun of php? (Score:4, Insightful)
Well. That might be true.... For those few sites which actually DO require 'scalability', easy maintenance when the project get bigger and the target is millions of hits per hour/day for some really heavy computations and what-not.
But there are SO few of these projects around. So for all of you who thinks php stinks at least try to use the right tool for the right job. From my experience in web-application development in Norway almost every large software company will recommend some closed source, inhouse made, 'superheavy' application for whatever site you want to have. They will use every argument you post here to put their software in a better light than some 'light weight solution' like PHP/Apache/Linux/MySQL/postgresql.
Seriously, almost no web-sites in Norway targeted at norwegians will ever require 'large scale' solutions. There simply aren't enough people around. Still the companies will push forth their solution on unsuspecting customers.
I had a e-commerce site I made (using php/apache/mysql, python/perl for backend functionality running on TSLinux), reviewed by a respected IT-consultant company in Norway (Bekk - http://www.bekk.no/). Their conclusion was that it was a good solution, well written, but.... "It should have been made in a java/C# or something like that" Why? Because of scalability.
It's just absurd. They really don't take into account the target marked for the solution. And the current system setup is running just fine and dandy without any trouble. Should the number of visitors increase ten-fold (which it never will), well... Add some slave database servers and more webservers.
Suddenly you have the board of directors going: -Uhm, why didn't you write the system in Java. We hear Java is a good thing. Java is scalable. Java is more secure.
Why? Because it took me such a impossible short time to make the site with php and it's been going for 2 years now, without problems. That's why.
The solution they would have otherwise chosen would be 10-100 times more expensive, would require expensive servers and would probably take years to develop.
Re:Making fun of php? (Score:5, Insightful)
"It's just absurd. They really don't take into account the target marked for the solution. And the current system setup is running just fine and dandy without any trouble. Should the number of visitors increase ten-fold (which it never will), well... Add some slave database servers and more webservers. Suddenly you have the board of directors going: -Uhm, why didn't you write the system in Java. We hear Java is a good thing. Java is scalable. Java is more secure."
I've encountered this a few times myself but I have a different view point on it. I agree that many sites will never grow enough to worry about scalability but the one thing that does almost always happen is new features being added.
I've personally seen a few PHP sites that run flawlessly but they are not easily extendable. They are written in such a manner that developers are afraid to work with it because it's too easy to break stuff, or adding new features will involve rewriting big chunks of code. I will admit that I've seen this in other programming languages as well such as .asp and .jsp/java.
If you consider programming styles such as struts [apache.org], cocoon [apache.org], webwork [opensymphony.com], etc. which encourage the MVC pattern it makes huge difference in the maintainability of web applications down the road. I find that java applications tend to use either these types of frameworks or custom ones that follow the same idea while I find many PHP applications are more like spaghetti code that do work fine but are a nightmare to add to in the future. They are quickly built but the lumping of PHP code in HTML makes it hard on projects where designers need to update the look and feel of a website but have no idea how to change their pages without mucking up the code.
I'm not saying that is the case all the time but what I am noticing is that PHP is gravitating towards OO programming and seems to be encouraging the separation of business logic from presentation logic, which is a very good thing. The argument that PHP is not as scalable as Java really should be more like PHP is not as extensable or maintainable as Java, but this certainly seems to be changing for the better.
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An excellent book. (Score:3, Informative)
This book deals with those advanced topics in substantial depth. Want to know what strategies should be considered in deciding how far to abstract database classes? Want an in depth discussion of preformance caching? Care to contemplate the values of various distributed architectures? Interested in Zend engine internals? From coding style clear through application benchmarking, this book covers it, and it covers it thoroughly and engagingly.
Re:Advanced PHP programming (Score:5, Funny)
I think we can add this title to the list of contradictory terms:
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Re:Advanced PHP programming (Score:2)