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No Nonsense XML Web Development with PHP
Posted by
samzenpus
on Wed Mar 15, 2006 12:46 PM
from the serious-development dept.
from the serious-development dept.
Alex Moskalyuk writes "PHP and XML seems like a marriage made in heaven. Powerful manipulation functions and support on the core language level in PHP5 combined with universal extensibility of XML make it a technology of choice for quite a few Web enthusiasts and companies out there. However, anyone inspired by PHP's ease of use can probably find a good cure from insomnia when facing with XML specs. With all the DTD's, XML Schemas, XSLT and XPath queries one can easily get the impression that the world is changing on them, and perhaps sticking to hard-coded HTML with PHP statements combined with SQL statements for data retrieval would be within the zone of comfort." Read the rest of Alex's review.
| No Nonsense XML Web Development with PHP | |
| author | Thomas Myer |
| pages | 354 |
| publisher | SitePoint |
| rating | 9/10 |
| reviewer | Alex Moskalyuk |
| ISBN | 097524020X |
| summary | XML, XSLT, XPath and DOM primer for PHP developers |
Thomas Myer's No Nonsense XML Web Development with PHP is an XML primer for those who have been exposed to PHP, but are yet waiting to appreciate the elegance of PHP+XML solutions. Throughout 10 chapters and 2 appendices Myer is introducing the reader to different aspects of XML, their best-practice implementations in LAMP (where last P stands for PHP) environment, and their relevance to the real world. For the real-world example Myer decides to guide the reader through writing a custom content management system - complete with publishing/admin interface, templating/presentation layer, search engine, RSS feeds and other commonly expected features.
The book is not an introduction to PHP, but it does assume that the Web developer knows what XML is, but has never dealt with it. So the first chapter just talks about properly parsing XML with IE and Firefox, validating an XML document, differences between a well-formed and a valid XML document. Overall, it provides a very good introduction to XML for someone who has never dealt with it, and could probably be skipped by developers with XML exposure.
Chapter 2, XML in Practice, goes into nitty-gritty details of XML, and 26 pages later the reader knows how to create an XML file to display in the browser, declare proper namespaces, attach a CSS file to existing XML file and display the proper XML+CSS file (look, Ma, no <html>!) in the browser. The author earns instant geek credibility by displaying Firefox screenshots, with the exception of IE screenshot whenever IE is discussed. At the end of the chapter the author takes us through the basic XSLT.
DTD's, XSLT and writing a practical PHP app take up the next three chapters, followed by XML manipulation chapters. JavaScript enthusiasts will probably find Chapter 6 pretty useful, as it discusses manipulating XML on the client side, working with XSLT, and creating dynamic site navigation based on the XML source. Chapter 7 is what one would expect from the book that has the words PHP and XML in the title - discussion of SAX, DOM and SimpleXML parsers, examples of their implementation, discussion of proper use cases for each one of the technologies. The SimpleXML subchapter also contains a good primer on XPath - a query language that allows the developer to provide the parser with a query to navigate down the XML document.
Chapter 8 takes the reader through RDF and RSS, discusses the ways the syndication feeds are used on the Web nowadays. Since throughout all these chapters we're building a content management system, this is the right time to add the RSS headlines functionality to the site. The next chapter discusses another practical implementation of XML on the Web - XML-RPC calls between the sites and proper ways of exchanging data via XML Web services. The chapter discusses SOAP, although not a whole lot, and just mentions REST as another way to implement Web Services. As a practical exercise, the author takes readers on a tour of building an XML-RPC client, server and connecting those two together.
The last chapter talks about using XML with databases. Native XML databases are discussed, but let's face it - most of the PHP development is done with relational databases anyway. Myer talks about exporting MySQL database contents into XML with phpMyAdmin and mysqldump. The first appendix includes function reference for SAX, DOM and SimpleXML parsing in PHP, while the second one completes the CMS project by providing the rest of the necessary files.
I found the author's style very easy to follow and approachable. The code samples are succinct and to the point, there are also no generic discussions, such as "Why PHP?" The project chosen for the practical implementation is a bit boring, but at the same time quite real-world. The screenshots are clear, and code examples are nicely highlighted. The errata is provided on the book Web site. Code archive is available as a single file download as well. The book site also provides 100% money back guarantee (less shipping and handling fees) to anyone who bought the title, and didn't feel like they were getting their money's worth.
However, there are a few drawbacks that I noticed as well. With topics like XSLT and XPath broken into several chapters and discussed in smaller chunks, it's hard to use the book as a reference later on. Appendix A with PHP function reference for XML parsing hardly seems like a worthy addition, since PHP manual page on the subject contains equivalent information with more real-life examples contributed by users.
With all that, the book is quite informative, educational and useful. The author manages to tackle quite a few difficult topics in 260 pages provided to him (the count excludes preface and appendices). However, kudos to the author for writing chapters on XML without sounding boring, redundant or too academic. I would highly recommend this book to anyone interested in developing PHP-driven Web sites that provide or consume Web services, work with XML data or generate XML for others to use."
You can purchase No Nonsense XML Web Development with PHP from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.
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Better matched, perhaps, than Perl & XSLT (Score:3, Insightful)
(Last Journal: Monday May 22 2006, @07:16PM)
Re:Better matched, perhaps, than Perl & XSLT (Score:4, Informative)
(http://www.ratemypiratejoke.com/)
Any recent install of java will almost certainly have an xslt processor on it, you just have to remember the magic incantation:
java org.apache.xalan.xslt.Process -XSL [template] -IN [file]Code Download (Score:5, Informative)
(http://www.massassi.net)
Can't please everyone, can you? (Score:5, Interesting)
(http://www.dixie-chicks.com/ | Last Journal: Tuesday July 24, @05:17PM)
Michael, a web programmer, February 7, 2006,
Almost worthless.
Based on the title, one might presume that Myer and Marini wrote the book for people who are already familiar with PHP and XML and want to learn some advanced techniques for combining them. What he gets instead are long (relative to the book itself), superficial introductions to PHP and XML and tiny, trivial examples of their combination. Everything in the book is common sense to someone who already knows PHP and XML. What the book teaches to beginners, however, is effectively useless for its superficiality, so I'd discourage anyone, especially beginners, from reading this book, even if he receives it for free. Time also is too valuable to waste on this book. Read 'PHP and MySQL Web Development' by Luke Welling and Laura Thompson and 'XML 1.1 Bible' by Elliotte Rusty Harold. One can visit SitePoint's web site to find a list of their titles and then return to a vendor site to read product reviews. SitePoint books are generally sub-par. This book is no exception.
Somewhere, someone at bn.com is shaking their head, wondering if this "reader reviews" thing is all that good a deal after all.
(FWIW: I think the book looks like just what I need, with my n00b level of knowledge of PHP and XML but with hopes to put them together myself [magicnumbers.org], if I can just find the right feed.)
XML/XSLT is often more work than it's worth (Score:5, Insightful)
(http://www.omninerd.com/)
This isn't intended to be me bashing XML/XSLT, but more of a warning. If you plan to use these two, ensure you fully understand them and how they will tie into your site. I've found with OmniNerd that XML/XSLT solutions are very nice for the more static or semi-static content and that using PHP to generate XHTML directly from the database is better suited for dynamic content.
Whatever you choose to use though, good luck!
Re:XML/XSLT is often more work than it's worth (Score:5, Insightful)
(Last Journal: Friday April 07 2006, @09:22AM)
XML is good for transferring data between systems. It is not good for storing data, which is what databases are for, or presenting data, which is what applications are for.
Re:XML/XSLT is often more work than it's worth (Score:4, Insightful)
(http://www.omninerd.com/)
Well, in the classroom you may be correct, but when you're looking for solutions, XML is often times a better place to store static data than a database. A perfect example is on OmniNerd, when one of our articles gets Slashdotted, or we think it's going to be, we bypass the database and create a static copy of our article in XML. It's faster since no "thought" is required to query specific data as it's all just there. The results have been that our server doesn't flinch when the massive wave of HTTP requests hit our site.
I also use it to store data for parts of the site that remain static. Why insert my FAQ into my database if it's not structured in a dynamic manner? It's far easier for me to go edit an XML file than run a bunch of queries, and we already mentioned the removed burden from the database.
Consider the alternative of storing it in an XHTML file. If I change the style of my site, then I have to update the XHTML file too as it's static. I can quickly translate the XML via XSLT with PHP, ASP, etc. There's no need to touch the data when I make a structural change. So given the static nature not requiring a database, the desire for easy updates, and the need to remove data from structure, I still choose XML.
So, yes, from a purist perspective it's for describing data. But from the perspective of someone trying to run a functional and effective site, it can be useful for storing certain data as well.
Re:XML/XSLT is often more work than it's worth (Score:5, Insightful)
(Last Journal: Friday April 07 2006, @09:22AM)
Re:XML/XSLT is often more work than it's worth (Score:4, Insightful)
(http://picknit.com/ | Last Journal: Saturday July 29 2006, @03:58PM)
XML is a key technology, and much underused by my profession, which still relies too much on FrameMaker, Word, and (God help us!) plain old HTML. But it's not the solution to every content management problem.
A compromise? (Score:5, Insightful)
(http://www.candysporks.org/)
Some quick advantages:
So even if you don't want to get into XML, XSLT, etc. then using the DOM for page generation is a much better solution than the traditional mixing HTML into PHP into files. The only qualifier to that I can think of is very small sites and when you don't have said libraries and such built up.
When else would hard coding HTML be preferred? I'm drawing a complete blank.
Re:A compromise? (Score:5, Insightful)
The downside to using the DOM as you describe is that you need to generate the whole document before you start sending it. For example, imagine if Slashdot used your approach - on a page with hundreds of comments, you'd have to wait for every last comment to be added to the DOM before you even started to send the headline to the user.
PHP is a tool of the homosexual interent agenda (Score:1, Funny)
Praise Jesus!
Present in PHP5 and PEAR for PHP4..but where else? (Score:2)
(http://arc.nucapt.northwestern.edu/F/OSS)
Match made in heaven? (Score:2)
(http://loewald.com/)
You don't order nonsense, honey--it just comes (Score:2)
(http://alexcruise.com/ | Last Journal: Friday November 08 2002, @06:29PM)
It's getting boring... (Score:2, Insightful)
(http://wickedindustry.com/)
- PHP saves granny from death
- How to build nuclear reactor using PHP and components from radioshack
- Reliable extraterrestial exploration using php.net functions reference comments
- PHP programmer cured from cancer, aids and herpes (aciquired while trying to understand any basic computer science topic)...
- PHP Saves! Better than Jesus!
- PHP - a quick guide to shopping.
C'mon nerds - trying to manipulate XML with common PHP functions is like trying to hang a picture on your wall using McDonalds fries, average sized elephant and twenty years old issue of playboy magazine. Ok, I have no problems to use PHP for what it's intented - quick, dirty and unmaintainable html generators occasionally attempting to simulate functionality of even the most basic OO languages, but please - everything has its limits.
P.S. I occasionally do XML for living. And XSLs are simple.
XML data and HTML middleware (Score:3, Interesting)
(http://www.graflex.org/klotz)
A lot of the middleware that converts data to HTML and back can go away when you use the right XML tools. XSLT does a good job of presenting static pages, and it can be fast if you cache the results as well.
But for dynamic pages (and forms) XML to XSLT to HTML leaves some big gaps:
These are some of the reasons we updated the W3C HTML forms module [w3.org] to take account of XML data directly.
How does it fix the above problems?
Nice work if you can get it, you say? Well, as everyone knows Microsoft hasn't yet implemented XForms. (Heck, they haven't even implemented CSS, though we hear they do have it as a goal now.)
So what can you do today:
Here's a quick example:
Let's suppose you have a book list you want to view, avaialble at http://example.com/books/list [example.com].
If you want to display this dataThis book is useless... (Score:1)
I was disappointed to find that the author barely used php5 dom functions to support the CMS (if you can call it that) that you are being tutored along because that is definitely one of php5's strong points. i was looking for a book with function references and some code examples, they were there, however, only for the simpleXML class.
in reality if you wanna build a php/xml cms, you're going to need to use php4.4+ and either write or use one of the many classes out there for actually parsing/writing xml.
Match made in heaven (Score:3, Funny)
(http://limi.net/)
Is that another way of saying that they deserve each other? *ducks*
Joy and Sorrow (Score:5, Insightful)
(http://web.lemuria.org/)
PHP is losely typed, full of hacks (excellent hacks that make coding easier) and is great exactly because it allows the coder to be pretty careless and have the language look out for him as far as possible.
XML, on the other hand, is strict and harsh on the coder. Forgot to close a tag? Wrong character somewhere? Not got the tag order correct? Sorry, your entire tree fails parsing.
They just don't mix well, and it shows everywhere. I'm currently coding a PHP app using XML-RPC, and gosh is it convoluted. You've gotta cast practically everything into the special XML-RPC values and back out again. You'd expect the libraries to have functions doing that for you, but you'd be mistaken. On the average line stuffing together an XML-RPC call, the whole "new XML_RPC_VALUE" stuff takes up twice the space of the actual variables.
Doesn't mix well. Sorry, I like PHP a lot and XML is an excellent thing. But they just don't mix well.
So You Want To Learn PHP5 and XML... (Score:1)
http://www.sitepoint.com/forums/showthread.php?t=
if you know some cool php5 / DOM / XML / XPath / XQuery / XSLT scripts, be sure to visit and share for all the newbs.
i have set up a few example scripts to get you started. others are more knowledgeable than i and can answer more specific question, too.
i've found learning the DOM to be a royal pita. php4 is very very different than php5. different versions of php5 behave very differently. my recommendation - get the latest and greatest php5 version. examples in the php online manual often don't work. there are undocumented capabilites.
as a trick, you will likely find more information about xml when googling "javascript xml tutorial" or "jaascript DOM tutorial" - and then you can convert the code to php5 class style. it will often work.
it is pretty cool, but it is a pita if you are swinging in the dark. too much missing or bad information. not very many examples that actually work - or examples that work with php4 or eralier versions of php5 but won't work with php5. or examples that just plain don't work!
good luck!
Signed up just to say DON'T BUY IT! (Score:2, Informative)
(http://leftjustified.net/)
Ok, so it's no good for beginner and too basic for anyone else...
One positive note though -- the introduction to designing and using DTDs is quite good, especially for newbies, but that alone is not worth the price of the book.
Purchasing this book also resulted in a regular flow of Sitepoint spam until I wrote an abusive email to their marketing department saying that I had most certainly never ticked any of their "Spam me to death" checkboxes and that I couldn't be any less interested in discounts on their books. Surprisingly, their response thanked me for the honest feedback.
At least it ended well
Read my own review of the book... (Score:1)
(http://webstandards.raquedan.com/)
Here [raquedan.com]
It's brief but I hope it helps. It's a good book by the way.
Re:wut (Score:3, Insightful)
XML stands for Xtremely Media-hyped Language and PHP stands for Perl-Hater's Platform. They are both very overused and should be ignored from this point on. Oh crap. I guess I get a free downmod for going against Slashdot culture. Oh well.
No, you should get the downmod for posting a moronic comment that contains flamebait only with no facts or even anecdotes to back it up. You rightly deserve at least a -3 for such a comment.
Malice (Score:5, Funny)
Dude, calm down! Hating Perl is not something developers do out of malice. It's a bit more like the obvious conclusion a child draws about fire after getting burned for the first time. Of course there are also some people, like you for example, who enjoy pain....
Re:wut (Score:1)
(http://libtom.org/)
I'm not saying XML isn't useful I'm saying it's not that impressive as a "technology". It falls under say the Dewey Decimal system in terms of excessive usefulness to society.
PHP on the other hand ain't bad. It's a bit simpler than Perl and IMHO meant to be a bit more lightweight. In the grand theme of things there is no reason why you could SSI perl script [hint: I did it with a CGI script that would parse my own special brew of perl/html].
Tom
It's not just key/value pairs. (Score:4, Informative)
(http://www.keegan.org/jeff | Last Journal: Thursday October 16 2003, @05:50PM)
In an XML file, I can throw in extra attributes or elements that won't be read by an old version of an app that wasn't looking for them. In a simple comma-separated-values layout, if I add something to the format, it's completely incompatible with previous versions.
The most complicated tools you have for comma-separated values are along the lines of cut and sed. When you have an XML document, you can convert it to *any* other XML format with a simple XSLT stylesheet (or, for that matter, into non-XML formats). SQL-Select-like statements can be represented with XPath, letting you select various fields of nodes which contain a certain attribute, act on the a certain way, etc.
Any anyway, would you look at an HTML document and say "it's just key-value pairs"? No! The order of elements, the hierarchy of data, etc, all makes up the page as a whole. HTML was an application of SGML, which XML was derived from.. Use XHTML if that last bit confuses you - it's not key/value pairs.
People have thrown the buzzwords at you because they're either really impressed with the technology, or because they're the kind of people that like buzzwords. Ignore the latter group of people, and try to focus on why those of us in the first group are singing its praises.
Re:wut (Score:4, Informative)
And BTW, XML is a tree format, not strictly key/value. And when you parse an XML file, you're never having to do direct text manipulation (which is error-prone). You're either receiving the information stored in the XML file as a series of events (SAX) or you're manipulating it via an object model (DOM).
Re:wut (Score:3, Insightful)
That said, as any Lisp programmer will tell you, tree-structured data is a Good Thing(TM). There's a reason why reading in input like:is complicated and fragile, whereas reading in input like:is so trivial that, well, I just typed this into DrScheme:and copy-pasted the second one into the input box, and DrScheme understood it perfectly.
Regexps are basically a hack to deal with data, like the first log file (which is what it actually looks like on my system), where the structure has been compressed/eliminated. In a perfect world, everything would be tree-structured, and none of those hacks would be necessary.
But wait... that's XML!It's harder to read than the parenthetical version, and slightly harder to parse (especially if there are attributes inside the XML tags), but the two are basically equivalent.
In Scheme, at least, you can build a generic XML-to-s-expression parser that will allow you to deal with any XML data that comes at you as easily as if it were parenthetical. And by generic, I mean that it can deal with any (well-formed) XML data ever. By contrast, regexps are fragile by definition. Even splitting along whitespace isn't always safe.
As far as PHP goes, I couldn't care less... it's both slower and less flexible than Scheme. What a combo! (Of course, Perl is too...
Re:wut (Score:4, Informative)
I think the parenthetical version and the XML version are about equal in terms of readability once you remember that any decent editor will have syntax highlighting to emphasise the text over the tags and that both versions will typically be split over multiple lines. Linebreaks don't really aid readability when you have short ending delimiters, but they do when you have longer ending delimiters.
The idea that XML is just a reinvention of s-expressions is quite popular, but this article [prescod.net] does a decent job of explaining how they differ.
Re:XML Web Services with PHP? (Score:2)
"Web services" is just a buzzword. There's no specific API you need to use. Your use would be called "REST" or "POX" by many web services people, so long as you use the right HTTP verbs (e.g. use DELETE not GET to delete things).
You aren't going to get significantly leaner than PHP if all you are doing is outputting XML. As for the choice of XML over JSON, CSV, YAML, etc, it really depends on what's going to be consuming your data. XML isn't the only solution, but it's probably the best supported and has the most mindshare.