E4X Doesn’t Suck

I’ve spoken on past occasions about how un-excited I am about E4X (ECMAScript for XML) with regards to ActionScript 3. Macromedia (now Adobe) made a strong push for XML for 3 player versions. Flash Player 5 had both a built-in XML parser as well as the XMLSocket connection. Flash Player 6 greatly optimized the XML parsing routines and Flash Player 7 did it again.

Problem was, for application developers dealing with nTier systems (fancy way of saying connecting to various backends), XML wasn’t the most succinct way of communicating, and those messages sometimes were a non-portable, made up language. By then, I was delving into the worlds of WebServices and Remoting. While SOAP implementations utilize XML in the underlying guts of how it works, you as the developer certainly feel like you’re writing regular code talking to code on some other server.

So, in building a prototype app using Flex 2, Cairngorm 2, and Ruby on Rails, I’m dealing with copious amounts of XML. I feel like I’m in middle-school again. It frightens me to hear myself say that as that same arrogant, holier-than-though attitude of non-big-company technologies is what I used to loathe when talking to Enterprise programmers. I can remember not just me, but countless others accomplishing a lot with just XML strings parsed by hand with very effective outcomes.

Either way, the thing that is different now is that I have E4X at my disposal. I’m the only one on the planet who feels that the old syntax is ok to use instead and isn’t overly verbose. I guess growing up with firstChild.childNodes makes you numb to the pig-latin you speak in code to get at your data. E4X, unintentionally, I perceived as more verbose because I am trying to learn as well as all the ActionScript 3 packages, mx packages, and countless other new API’s & methodologies at the same time. Spending 40 minutes on getting a new for each loop to work, referring to the docs twice, is all the temptation I need to say, “Fuggit, the old way works just fine, I know it well, and it’s faster at runtime than E4X anyway… why bother with this bs when the syntax isn’t that much cleaner?”

Many would disagree. I debated with the top Flash minds twice in the past, all with next to no support. Many fawn over it. While I was visiting my boss in Des Moines, Iowa, he took it upon himself one evening to show me some refactored XML to E4X code. He was overjoyed… I didn’t care. Granted I was happy he was happy. He went from 5 verbose lines to 3 cleaner ones.

“Ok… you’re still parsing… parsing blows.”

I don’t have a choice with Ruby on Rails. Maybe I do, and don’t know it. There is so much stuff I don’t know about ROR, but I’m going with what I got, and what I got is a consistent and readable messaging schema between Flex and Rails. Rails sends easily understood XML messages, and the ones I send to it, it can read just fine. However, after writing my Delegate to speak the CRUD methods to my Rails controller methods, I really wasn’t looking forward to writing a gigantic Factory class to convert Rails XML messages to Array’s of Value Objects, and vice-versa.

I’m still not, but found a really easy way to implement it. And thus, I get to why E4X doesn’t suck… I didn’t know it, but E4X supports binding, just like Flex does for binding variables to other variables. Suddenly, my ValueObjects who already implement a toString method to ease debugging:

public function toString():String
        var s:String = "";
        s += "[class ProjectVO";
        s += " id=" + id;
        s += " projectName=" + projectName;
        s += " updatedDate=" + updatedDate;
        s += " creationDate=" + creationDate;
        s += " ]";
        return s;

Now have a nice way to get their XML equivalent:

public function toXML():XML
	var updatedDateString:String = DateUtils.getRubyDateString(updatedDate);
	var creationDateString:String = DateUtils.getRubyDateString(creationDate);
	var xmlified:XML =
			<updated-date type="date">{updatedDateString}</updated-date>
			<creation-date type="date">{creationDateString}</creation-date>
			<id type="integer">{id}</id>
	return xmlified;

Now, for my HTTPService, I can just do:

service.send ( myProjectVO.toXML() ) ;

It’s also really easy to update in case the Rail’s side changes for whatever reason. I usually can just copy from ServiceCapture, paste into the VO class since XML can now be written without quoting rules, and swap the values with bindings to the VO’s public properties… nice!

I don’t apologize for all the things I said, but wouldn’t have been so non-enthused had I known about bindings.

…so… uh… anyone got Remoting working for Rails yet? Or at least a WebService way of using Rails vs. frikin’ HTTPService?

I got Flash to talk to Rails

I went through this tutorial, and replaced all the Flex stuff with 56 lines of ActionScript in Flash 8. Getting XML into Flash is the Flash Developer’s tried, true, and trusted way of getting dynamic data. Took me 30 minutes in total: 30 seconds to do the rails setup, 20 minutes to install/uninstall/reinstall MySQL 4.1 (POS!!!), and 5 to get data. I spent another 15 unsucessfully sending XML to the create method. It was creating records, but wasn’t getting the XML I sent. I tried every version of the XML object I know to no avail.

Here, I created the XML string by hand:

function createUser()
	var s:String = "";
	s += "<request>";
	s += "<user>";
	s += "<updated-date/>";
	s += "<creation-date/>";
	s += "<username>doom</username>";
	s += "<id type='integer'></id>";
	s += "<password>heck</password>";
	s += "<email>doom@finalbattle.com</email>";
	s += "</user>";
	s += "</request>";

And then here I send the request:

create_xml = new XML();
create_xml.ignoreWhite = true;
trace("sending: create_xml: " + create_xml);
create_xml.contentType = "application/xml";
create_xml.onLoad = function(success)
        trace("create success: " + success);
create_xml.sendAndLoad("http://localhost:3000/users/create", create_xml, "POST");

I opened ServiceCapture and started examining the traffic, and nothing jumped out at me. I got pulled away to do a Podcast so I’ll just have to do it in Flex, and compare since I’m probably just not formulating my XML message correctly.

Anyway, damn yo… 5 minutes to read from and write to a DB? Awesome!

Agile Web Development with Rails First Impressions

Can’t sleep (as usual) so figured I’d write up my first impressions of Ruby and Rails after reading the first 8 chapters of Agile Web Development with Rails Sunday afternoon. Let me precursor this with I’ve only read 8 chapters in 1 book in a 7 hour period over 2 days. Anything stated below are my first impressions, and my opinions are preliminary and fleeting at best. As I learn more, I know what I think will change.

Rails? Really nice.

Ruby? No opinions yet, don’t know enough about the language.

ERb? Hate it.

Rails itself, at least from an implementation standpoint, seems to do all the things people hand-code themselves a lot of times. They keep re-iterating convention over configuration. This statement scores a lot of points with me because there are a lot of frustrating things I’ve had to do with Java projects. OpenAMF + Hibernate + Spring == XML hell. While I usually don’t have to deal with it since I’m client boy, I inevitably was drawn in on a few occasions, and hated it. I don’t mind configuring something if it’s going to work when I’m done, but time and time again, I felt like I was doing a form of coding (as were the Java guys) whilst playing with XML. I’m sure it scales, but I never really saw it run for more than 1 hour.

I’ve been pretty shielded from the ColdFusion project I’m currently on. The JRun + CF + SQL setup was an all day affair, and I only had 1 hiccup since. While I attribute part of that success to an extremely talented team, I must say I’ve been impressed; the only times things break is when my code is involved. In all fairness, the server-side code isn’t really worthwhile without the client, and vice-versa. Can’t test it till I get done and start to integrate.

Still, the VO’s are a monotonous pain to write, and I’m sure the server-side CRUD methods are as well. It should by automated at this stage of the game.

I remember when learning OOP, then design patterns, then frameworks like ARP and Cairngorm, you start following conventions. They are known, ingrained, and the decision to use them is intentional. You knowingly write more code to accomplish the same thing knowing that the extra code pays off later. This is where I’ve seen conventions, in a small part, pay off time and time again. So, while I’m sure there are a few things Rails disregards on purpose, I have faith in conventions, and how they have improved my programming results over the years. Thus, I have faith in Rails.

I still think, though, configurations are powerful and should not be disregarded. Just not sure where that fine line is, nor the ramifications for crossing one or the other.

It boggles my mind to think this hasn’t been implemented yet in Java, CF, or PHP yet. I’ve heard briefly information about Tapestry, and when it was explained, it sounded like the same thing, only the AWDWR book took a stab at it. I know CF has a gazillion frameworks for it, and even read 2 blog entries about CF on Rails awhile ago, so I’m sure someone’s already got something “good enough”. I’ve heard of Cake and a few other PHP frameworks, but the thing I’ve always found about PHP stuff is that unless you can read and understand PHP, you cannot really grasp the power of most of what I’ve seen. For example, going to the bookstore, or even your local user group, and you get someone to give you the gist of Fusebox for ColdFusion, or Rails for Ruby… but Cake for PHP? I don’t know, I just get the impression that the communities are smaller, and those who get it are smart enough to do so without documentation, or some sort of developer evangelism. Bottom line, I don’t trust my knowledge of server-side frameworks to really question that something of Rail’s caliber doesn’t already exist. I just know in reading those 8 chapters, I got it pretty quickly and would rather do that than write DAO’s in PHP all day. If I were a full-time server-side developer, I would probably know more about what tools are truly available and thus would have better context.

Nothing to say about Ruby yet.

The ERb’s bring back nightmares of ASP & PHP projects I’ve seen which have sql statements embedded in the page, and someone wanted me to “modify” it. Ugh, run. While I think their templating mechanism is straightforward and simple, I still feel that ERb’s are gross. One third of that is my past experience with ASP, PHP, and JSP which is admittingly (and thankfully) little. For simple projects, or simple data accessing components for Flash, they do their job and do it well. For anything else, hell no. The 2nd third is because to me, CSS & HTML are limiting. While HTML & CSS certainly offer a neat way to show text, display it, and control layout (for the most part), the whole page based metaphor feels like it’s only scratching the surface of Ruby on Rail’s potential. While I think they did an effective job using Controllers to not only give scoped variables for the view to use and built-in mixin methods which inject functionality at runtime, it’s the actual “pages” that makes me dislike it. Why pages? I know, I haven’t hit the AJAX parts yet, but still, I’d rather use Flex to handle all of the state, sections, and even session data. However, I can’t figure out yet how I’d write my Controller code once you add a stateful client to the mix. Steven says you can expose Ruby as webservices… perhaps that’s the ticket?

Furthermore, it’d be really neat to learn some of the guts of the automation routines and write MXML & AS files on the fly, compile with mxmlc, and generate those auto-CRUD pages into a single SWF; a Flex app with a richer, and more central & self-contained GUI as a front end. Again, those CRUD pages aren’t necessarily supposed to be your de-facto admin pages, but if you have a better GUI tool that can integrate into Rail’s automated nature, why not use it?

Overall, the ActiveRecord, after talking to Steven on the phone, and then reading about it Sunday, pretty much is what hooked me. While I still feel the pull of databases driving my projects, writing a class representation of a table and having that transparently save, update, etc. is just off the hook. I still don’t get why some of that stuff, like parent_of and foreign keys, etc. isn’t automated, but the book had a few footnotes talking about database disparities.

Either way, it’s fuggin’ pimp looking for a version 1.0 framework.