David S. Gale

Programming, Life, and what I think about it all

APEX 4.2.2: Sample Dynamic Actions

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Continuing our series of posts looking at the various packaged applications available in 4.2.2 (most of them are also available in 4.2.1, but we’ve upgraded almost all of them at least slightly), I’ve decided to return to the sample applications. This week, I’ll focus on the Sample Dynamic Actions application.

I like dynamic actions. Quite simply, they are one of the most powerful features available to developers in the entire APEX framework. Of course, because they are so powerful, it is very easy to be overwhelmed, and decide to ignore them completely, which is unfortunate.

A little background, in case it’s necessary: Dynamic Actions are declarative objects which you can add to your APEX pages to do stuff in response to the user’s actions. You can use them to help a user find the information they’re looking for (one great way is to hide stuff they don’t need to see at the moment), or direct them to fields that have invalid data, or even refresh part of a page in response to a user’s change elsewhere. And you can stack dynamic actions–one action by the user can trigger multiple dynamic actions, or a dynamic action can contain multiple steps…or a dynamic action can trigger another one. Like I said, powerful and a bit daunting (at first, at least).

But the first step–before you start stacking dynamic actions with multiple steps to build bigger structures than my kids with their legos–the first step is to learn what you can do with the individual pieces. And that’s why we built the Sample Dynamic Actions app: to give you a taste of some of the things you can do with them. We don’t provide samples for every type of dynamic action, nor do we show you the upper limit of what’s possible. We’re still figuring out cool things to do with them ourselves, and once you start using them, so will you.

If you have a specific packaged app that you’d like me to cover in this series, or suggestions on other applications we should build and include in future releases, please feel free to let me know, either by leaving a comment below, or e-mailing me directly.

APEX 4.2.2: APEX Application Archive

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One of our main goals in building the packaged applications has been to avoid the problem which plagues almost every bit of sample code (and yes, I mean every–all platforms, all systems, all everything!)–namely, that samples are inherently not usable, and you need to spend time dissecting them before you can apply their lessons to your real-world issues. Thus, in addition to the Sample Applications, we've built–and continue to build–Productivity Applications, which ought to be usable more or less “out of the box”, as it were. One of the more interesting (to me, at least), is the APEX Application Archive.

One of the most common questions I've run into is, “how do I back up my applications?” Sure, you back up your database, so you could conceivably roll back to an earlier version using that–though I bet your users would come hunting with pitchforks and torches if you made a habit of it. Most of the time, the solution is to set up an automated process which exports your applications and checks them into version control–a system which I highly recommend.

As an alternative (or a supplement), you can use the APEX Application Archive to store your application histories in the database itself. One of the nice things about this is that we can tell if an application has been modified since the last time it was archived, and only archive the ones that need to be–a significant detail which is unfortunately easy to overlook when setting up a nightly backup script.

I do have to point out, of course, that if you unlock the application and look at the processes, you'll see that we're using a so-far undocumented API–a package called APEX_CLOUD_ARCHIVE. This means a couple of things:

  • Although we support the APEX Application Archive packaged app, we don't support the APEX_CLOUD_ARCHIVE package. So if you decide to get clever and build something using it–well, good luck. Oracle Support won't help.
  • The package may change in future releases. The packaged app would be updated to match, but anything you build on your own that uses it may break. Sorry.

Still, even with those limitations, this packaged application does show some of the power we've tried to build into the Productivity Apps–and like I said at the beginning, it's something that pretty much any APEX environment could use.

If you have a specific packaged app that you'd like me to cover in this series, or suggestions on other applications we should build and include in future releases, please feel free to let me know, either by leaving a comment below, or e-mailing me directly.

APEX 4.2.2: Sample Reporting

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Last week, I posted about the release of APEX 4.2.2, and promised to start blogging about the various packaged applications included with the standard APEX. Today, we'll be looking at one of the Sample Applications: Sample Reporting. Now, even if you think you know how reports in APEX work, I recommend taking a look at this application–and I'll tell you why.

Reports have always been one of APEX's biggest features–if you can't get data out of your database, what's the point, right? With a few clicks, you can create a report, change the format masks of columns, move columns around, hide them, change the sort order, build links; the classic reports are fairly full-featured. And that's not even mentioning the interactive reports, which were introduced in APEX 4.0, allowing your users to do all of those actions, without having to bother developers at all!
 
But that's not really why I want to talk about the Sample Reporting application. Yes, it shows you how to use a classic report and an interactive report, but the fun stuff is tucked away underneath the Use Cases and SQL Examples tabs–both of which are new in the 4.2.2 release.
 
Under Use Cases, you'll find a set of examples of how to do different techniques above and beyond the basic report functionality, many of which your users will thank you for. Want to add some filter functionality that's friendlier than what interactive reports give you? We've got examples for that. Want to include colorful buttons in your report? Yep, take a look. Some of the stuff may be old hat to you, but I'm hopeful that there are some examples that you'll find exciting and useful.
 
Under SQL Examples, we included a slew of reports specifically designed to highlight stuff you can do in SQL beyond the basic “select…from…where…order by” pattern. Analytic functions (which I blogged about here), regular expressions, inline views, and–one of my newest favorite techniques–pipelined functions are all demonstrated. Some of these are things that I still periodically need to look up, since although they're useful, I don't use them often enough to have memorized; this sample application can be a useful reference for these.
 
All of the reports include an expandable region which shows the SQL source behind the scenes, so you can see exactly how we're doing everything without having to go into the builder.

APEX 4.2.2

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As most of you know, APEX 4.2.2 was released last Friday. While the release was largely a stability and bug fix as far as the builder is concerned, it included some significant changes and improvements to the packaged applications. (Full disclosure: I'm on the team that has been building the packaged apps, so I may be a bit biased about them. But they're really cool, trust me!)

There are 18 productivity applications, and 16 sample applications; we're constantly working on adding more of each. The packaged apps are all built in APEX using functionality which is available to any APEX developer (read: we're not cheating! If we do it in a packaged app, you can do it too!).

The sample applications include demonstrations of how to work with APEX, and are meant to cover subjects from the very basics on up through advanced techniques; I highly recommend installing them each at least once, just to see what all they cover. These apps are all unlocked automatically, so you can view their code in the Builder.

The productivity applications are intended to be examples of applications which will actually be useful to normal database users. Too often, sample applications are built purely to demonstrate specific functionality, and it's difficult to see how it might be useful in an actual, real-world case; hopefully, the productivity applications will bridge that gap. They may not perfectly fit your need, but hopefully they're close enough that you can use them as a springboard to there. These apps are locked by default, which means that you can't open them in the Builder and edit them; this allows us to offer updates in future releases of APEX. If you want, however, you can unlock the applications and edit them; when a new release comes out, you can install the new version, port over any changes you need, and as long as you haven't broken the underlying table structure, everything should work. (Yes, “should”. No guarantees, sorry!)

In the next few weeks, I'll be going through some of my favorite packaged apps, and pointing out what I like about each one. Stay tuned!