Note: This blog post is from 2006. Some content may be outdated--though not necessarily. Same with links and subsequent comments from myself or others. Corrections are welcome, in the comments. And I may revise the content as necessary.

(As suggested in the entry's title, this is part of a series I'm doing on Spry. Be sure to check out the other entries.)

Make sure you understand your XML

I made a mistake of trying to eyeball an XML file's layout to determine the nesting needed to create the XPath value for the XMLDataset constructor. Oops.

[If you're new to Spry, I've likely just gotten way over your head! This entry is for those already checking it Spry. Newcomers should leave right now and go check out the "bolded" resources I point to in my Spry compendium for that sort of help....Go on. I'm serious! You won't appreciate the rest otherwise! :-)]

I was looking at an RSS stream that looked like this (abbreviated):

So I thought that the "rss" element was outermost and the rest, including my desired "title", were all children, so I set the xpath to be rss/title. And I got no generated output from Spry. Doh! It should have been rss/channel/title.

Here's a tip: open the desired XML file with some tool that shows you the XML in a nested tree structure. Perhaps easiest, you can just open the file using IE or Firefox (as of 1.5), which will show it using a special stylesheet that renders the XML in a nested structure.

Of course, if the destination you try to open doesn't respond with pure XML, you won't even be able to open it effectively with such tools, which will tell you that you have another problem (like forgetting to turn off debugging if generating XML from CFML, or forgetting to cause the CFML page to change the mime type to text/xml. More on both of those mistakes in a later entry).

Don't use spry:region on Table tag

Interested in creating an HTML table? OK, no noise please from the CSS crowd. Some of us old-timers are slow to the party or just don't gravitate to it for quick testing.

Anyway, I mistakenly assumed that if I wanted to create a table of multiple rows that I would just add the spry:region tag to the Table tag. I figured that since I would naturally want the spry:repeat on the TR tags, I should put the enclosing spry:region on the enclosing TABLE tag. Wrong! Should have RTFM.

Ok, I did. I just missed that. It clearly says in 2 of the key introductory articles that TABLE tags are one of many on which you are not to use spry:region. More important, the excellent Dynamic Table Tutorial also clearly shows how it's to be done.

You want to wrap the table, in a DIV for instance, and put the spry:region there. If you don't, you don't get an error. You just don't get any of the content you expected to be dynamically generated (which could appear to be a blank page or portion, depending on what you're doing).

Don't mistake spry:repeatchildren for spry:repeat

Similarly, I made another mistake when I copied a line of code to do the repeat, and I used code from an example that used spry:repeatchildren, rather than spry:repeat. Doh!

The Spry Data Set and Dynamic Region Overview says it best in describing the two:

One allows you to repeat an element and all of its content for each row in a given data set (spry:repeat), and another that allows you to repeat all of the children of a given element for each row in a given data set (spry:repeatchildren)

I have lots of other tasty tidbits to share, but they're more general than these related to me trying to write code from scratch.

Note: This blog post is from 2006. Some content may be outdated--though not necessarily. Same with links and subsequent comments from myself or others. Corrections are welcome, in the comments. And I may revise the content as necessary.

(As suggested in the entry's title, this is part of a series I'm doing on Spry. Be sure to check out the other entries.)

Spry is a client-side tool, first and foremost

Spry is a client-side tool, so on one level it's supposed to appeal to non-CFML developers, who don't have CFML (or PHP, ASP.NET or J2EE) to generate their HTML dynamically.

Spry is about processing XML received

More important, though, even for we CFML developers, you need to think beyond "just creating dynamic tables": the real goal of Spry is to process XML being sent to the client.

Consider, for instance, the situation where you don't control the XML being generated. Perhaps it's coming from an RSS feed or some other xml-generating product on your server (or on some other server, that perhaps you proxy on the spry request's behalf--more on that later, or in the Spry docs).

The point is that you may not then be able to (or want to bother) creating the display in CFML, leaving it instead to Spry to handle.

Spry is about more than "generating dynamic tables"

And Spry can certainly do much more than just create tables. It can create virtually any HTML code based on the data received. Tables are just a simple example most can grasp. We're already starting to see many other and more interesting examples.

Spry is about detecting and responding to page content and source data changes

Still more important, the real value in Spry--and it's true Ajax raison d'être (reason for being) is to do automatic regeneration of content based on changes to the source XML data or other selections on the page, which can include asynchronous communication on the client's behalf back to the server.

That's where things like the dynamic regeneration of regions (which change when the dataset their bound to changes) and master/detail "data references" (where data in one region changes based on selections in another region)really makes things different than "static" HTML you could build "dynamically" in CFML (or other web app platforms).

As I say in my Spry compendium discussed in my previous post, do take the time to learn more from the many available resources, especially the 2 key 30+page documents from Adobe. You'll get a whole new appreciation for what Spry can do for you.

Even so, do look for more posts here as I share some of the other common tips and traps I've hit as I (and others) have explored Spry.

Spry is about reducing bandwidth

Those who were around when Flash came out will recall that a big part of its advantages was that it permitted redesign of pages so that rather than transmit the entire page on each "request", the Flash client just requested the data needed to fill a given area of a page.

The same is true with Spry (and Ajax in general). If you can change an interface to retrieve just the needed data (rather than the full weight of an entire HTML page), that can make a big difference in performance and cost savings (hey, someone has to pay for that bandwidth in sending HTML from a server).

Spry is about reducing Javascript complexity

Going back to the first point, all this power comes in a package of tags that dramatically reduce the complexity of the coding needed to enable all these (and more) features. It's possible to create powerful interfaces and interactions with no (or just a tiny amount of) Javascript.

Sure, as we create more advanced interfaces, we may need to understand and use more Javascript. The good news is that both built-in and community-generated demos will help show the way in the near term, and in the long term I'll bet that more work from Adobe in the Spry framework itself will help make still more powerful interfaces just as easy and low in Javascript coding.

Spry is about reducing Browser Interoperability hassles

If you've looked at doing Ajax, you may or may not have had a hassle dealing with whether your code will work on one browser or another. Sure, most Ajax frameworks also try to hide that complexity, but just know that Spry does as well, which is a good thing if you have to deal with supporting different browsers.

There is even an approach to graceful degregation, or what Adobe calls "Progressive Enhancement", discussed at the end of Adobe's great 35-page article, Spry Data Set and Dynamic Region Overview, leveraging something called Hijax methodology.

Admittedly, if the browser doesn't support Javascript at all, that's a separate challenge and a bummer. The challenge of detecting and handling when JS is disabled is not really new to Ajax at all, and I'll leave that to the reader to research or for others (or a later entry here) to elaborate on.

Note: This blog post is from 2006. Some content may be outdated--though not necessarily. Same with links and subsequent comments from myself or others. Corrections are welcome, in the comments. And I may revise the content as necessary.

(As suggested in the entry's title, this is part of a series I'm doing on Spry. Be sure to check out the other entries.)

I've gathered together several of them, both to save you the work of trying to find them and more important to help you avoid missing key ones, especially ones that focus on CFML-related aspects.

Check it out, at:

http://carehart.org/spry/spry_resources.cfm

I'll try to keep it up to date with new community resources as they're offered, but of course some of the Adobe-provided compendium resources (pointed to on my page) will ultimately become the best place to find resources in the future. For now, I'm just trying to help while there are scattered resources. Drop me a note if you see something I should add.

Note: This blog post is from 2006. Some content may be outdated--though not necessarily. Same with links and subsequent comments from myself or others. Corrections are welcome, in the comments. And I may revise the content as necessary.

Free Screencast: What is Ajax
Get a taste of what Ajax is all about. Watch the entertaining and informative four minute overview [QT7 8MB] [MP4 12MB] or choose the more detailed demonstration with examples in our twenty-two minute screencast

It's from the folks at Manning Publications, publishers of Ajax in Action.

Note: This blog post is from 2006. Some content may be outdated--though not necessarily. Same with links and subsequent comments from myself or others. Corrections are welcome, in the comments. And I may revise the content as necessary.

Are you getting the error, "Connection refused" or "Error establishing socket to host and port", trying to connect to a SQL Server database from ColdFusion?

The short answer is:

Open the "SQL Server Configuration Manager" in SQL Server, then choose "SQL Server Network Configuration", and its "Protocols For [yourserver]" option. Open it and ensure that TCP/IP is enabled as a protocol. If not, enable it, and restart SQL Server. For the official MS docs on this, see it discussed in this related topic.

(In later versions, where you don't readily find that Configuration Manager, see my discussion below under "The solution" for other ways to get to that feature.)

And if it is enabled, right-click on that TCP/IP option, choose "properties", then its "IP Addresses" tab, and among the listed features, check if "ipall" (among the last in the list) has the port set to 1433 (or whatever is your SQL Server port), then restart SQL Server. More detail below. If you don't want to enable the "ipall" option, check the other entries to find the IP you're using (which may be 127.0.0.1 or ::1, if using "localhost" for the "server" you're telling CF to connect to), and ensure both that it's "enabled" and that its "tcp port" option is set to 1433. Then restart SQL Server and verify the DSN again.

Note that if it's still "not working" after you make these changes, do make sure you don't see a different error, like "Cannot open database "yourdbname" requested by the login. The login failed." :-) That just means you have a new and different problem to solve, now that this one is resolved. More on that below.

The rest of this entry explains additional details, such as how to find and make that change, what specific errors you get, and how I found the information, in case any of it helps others.

[....Continue Reading....]

Note: This blog post is from 2006. Some content may be outdated--though not necessarily. Same with links and subsequent comments from myself or others. Corrections are welcome, in the comments. And I may revise the content as necessary.

The mag was offered to all attendees at the conference and is also available as a subscription (paper only) at http://www.fusionauthority.com/quarterly/.

Note: This blog post is from 2006. Some content may be outdated--though not necessarily. Same with links and subsequent comments from myself or others. Corrections are welcome, in the comments. And I may revise the content as necessary.

IBATIS, at http://ibatis.apache.org/ is an alternative ORM approach based on a concept of SQL Maps, which in essence are simply SQL statements stored in XML files with a well-defined API for mapping and manipulating those in your app. The approach does not generate SQL for you, but rather is intended to serve as a means to segregate to XML files--and manage via an API--the SQL that may already exist substantially for existing apps or for new apps that may simply require some hand-coding of SQL. (The last sentence added after some comments suggest that this point made later in the post was missed.)

The benefit is that since CFML folks are already knee deep in SQL, it brings a measure of architecture without completely detaching them from the SQL they know and love (or at least tolerate).

If that sounds counter to other ORM approaches, which often generate the SQL automatically and/or intentionally hide it from you, that's because it is quite different. I'll grant that there are many who would benefit from having an architecture remove SQL from their control. It's just that this seems an alternative worth considering.

I certainly don't mean to knock at all the other CFML-based ORM implementations that exist already (such as Arf, ObjectBreeze, Transfer, and Reactor). Each approach has its place and pros/cons. As the other CFML-based ORM frameworks tend to be based on existing approaches from other platforms, I'm merely pointing out this alternative as a possibly useful model.

I'm also not offering here my own new CFML-based implementation based on IBATIS. But note that there are currently implementations for Java and .NET at the Apache site, so it shouldn't be tough for someone to leverage the Java implementation in CFML.

It strikes me that the IBATIS approach may be closer to the way fuseboxers and others segregate their queries into their own CFML file. Perhaps this approach of storing them in an XML file instead and using an API to access the results would offer a better though still somewhat familiar approach to abstracting queries.

I was sharing the idea with Sean Corfield at CFUnited last night, and he was intrigued. After I sat in on his excellent presentation on objects and persistence, we discussed it again and he had started looking into it overnight. Perhaps it could make it into FB 6? :-)

I'm hoping someone may want to take the ball and run with it. If you're intrigued, considering discussing it with Sean or take it on yourself, or just continue the conversation. Hope it proves helpful.

Note: This blog post is from 2006. Some content may be outdated--though not necessarily. Same with links and subsequent comments from myself or others. Corrections are welcome, in the comments. And I may revise the content as necessary.

That reminiscing got me thinking some thoughts that others might enjoy on the eve of CFUnited.

First, I'll say that I used to buy burgers at the "Gino's" that was near the spot where the conference hotel now stands. Here's a trivia question for my fellow long-time DC folks: do you know where Gino's (a burger chain now long gone) got it's name? I'm told it was Gino Marchetti from the Baltimore Colts. Wikipedia backs me up. :-)

Here's another: the large open air shopping center behind the hotel on Rockville Pike used to house a large Korvette's department store. Ever wonder about that name? I was told it was formed by some former KORean VETerans. :-)

I grew up skating at Congressional Roller Rink, which was also just up the road a mile (now long gone) in Rockville. It was the center of our lives for many of us, and a great, safe place to grow up. Well, we'd hop the train back and forth to either Rockville Mall or White Flint (which had just opened in the 70's), and I suppose that wasn't too safe. But we could find great old beer cans on the tracks--anyone else ever get into that collecting? Still have mine. I recently started a site to connect with others who may have skated/grown up at the rink, http://congressionalrollerrink.com. :-)

Moving forward a couple decades, those who have attended the Maryland CFUGs, where I used to speak often before moving to Atlanta, will know I've told the story that my ancestors farmed property just a mile away from the conference facility, across the street from where we used to hold the Maryland CFUGs on Parklawn Drive. In the 50's they sold the land and soon thereafter arose the big black Parklawn building.

One last bit of trivia, that few could answer: where and when was the first place I spoke to a CFUG audience? It wasn't the DC CFUG, run by FigLeaf, where I spoke often while I worked there in 1999-2000. It was the Maryland CFUG, back in Feb 1998. Sadly, the records of those early meetings are missing from the archives, but I have it at my old Systemanage site list of past presentations.

OK: one more piece of personal CFUnited trivia. Last year it was determined that only one person (other than Michael) had attended all the CFUnited events, back to when they were first called CFUN and held at the NIH facility. Um, guess who? :-)

If you have other fun CFUN/CFUnited memories or trivia, please do share.

/charlie

Note: This blog post is from 2006. Some content may be outdated--though not necessarily. Same with links and subsequent comments from myself or others. Corrections are welcome, in the comments. And I may revise the content as necessary.

As such, I'll point out that I'm speaking 3 times regarding 2 topics at CFUnited. That will be a great time to know you can find me, if you want to say hello. :-) Both talks are on web services, one beginner and one intermediate, and the beginner has been chosen by popular demand to be repeated on Saturday.

I'll welcome your feedback as well if you attend. Last year I was voted one of the top speakers, along with Glenda Vigoreaux and, I believe, someone else--I can't recall. We're supposed to get some form of recognition at this year's event, perhaps a special hotel room or something, so that will be fun. They think of such clever things, that Michael and Liz. :-)

I should note I'm also speaking at the CFUG Manager's event the day before, and I really look forward to saying hello to other CFUG Managers (I'm now presiding over the team who run the Atlanta CFUG).

Note: This blog post is from 2006. Some content may be outdated--though not necessarily. Same with links and subsequent comments from myself or others. Corrections are welcome, in the comments. And I may revise the content as necessary.

Have you ever assumed that for a file to be uploaded to CF, in a post to a CFM page, that that page needs a CFFILE Action="upload" in order to "receive" the file? It does NOT. Now, I'm being a bit technical here, but to be clear, the uploaded file will be "received" by CF, if posted to ANY CFM page whether that tag is there or not to "receive it". The point is that this uploaded file will be put in a temp directory, with a temp file name and extension, at least until the end of the request.

What the CFFILE Action="upload" does is just move the uploaded file from a temp directory to your named DESTINATION (as well as validate its type, report the file name, protect against or allow overwrites, and more, if you use the attributes on the tag for those features).

And if you do NOT process it, then that temp file will be removed at the end of the request (unless perhaps the request terminates unexpectedly).

Need proof? Want to learn more? Read on.

[....Continue Reading....]