Monday, 10 December 2007

UKOUG - Day 3

So with my presentation firmly behind me, and after having the best night's sleep in weeks, I headed into day 3 looking forward to catching John Scott talk about 'Debugging APEX Applications', Dimitri Gielis present 'Integration of BI (XML) Publisher and APEX (Oracle Application Express)' and also sit on the panel for my first APEX roundtable discussion group.

John's presetation was very good, he presented well and showed numerous techniques for debugging your APEX applications. Specifically of interest was the use of the DBMS_APPLICATION_INFO package which can be used to monitor progress of long running queries / reports and display this progress information back to the user. He also mentioned that as an APEX developer he believes that you have the responsibility to have a good understanding of the database, so as to be able to benefit from the features and build better applications, a point which I totally agree with. If you ever get a chance to watch John present, then do it as I'm positive there will be something in there that you can benefit from. Nice job John!

So then it was time to get ready for the APEX roundtable. I was pretty nervous and left John's presentation quarter of an hour before the end so as to go up to the room and get myself ready. The session was chaired by Jeremy Duggan (Chair of the Modelling, Analysis and Design SIG), and I was on the panel with Dimitri Gielis, Peter Lorenzen and unofficially, but answering a lot of the questions John Scott. Around 20 people turned up, which was reasonable considering it was lunch time! Some of the topics that came up were:

  • APEX / Forms / ADF
  • Choosing the right tool for the right project. This is a massive topic with lots of arguments for and against. For a good overview of the main factors, take a look at Duncan Mills' article, 'The Right Tool For the Right Job'. Also, if you are in the Netherlands, Dimitri will be discussing this with Lucas Jellema on Monday 17th December.
  • Validations
  • Specifically around the current issues with validating tabular form data. Dimitri mentioned Patrick Wolf's ApexLib framework which greatly improves tabular form handling, including out-of-the-box client and server validations for mandatory, date and numeric fields. Alternatively, if you don't want to or cannot use Patrick's framework, you can code your validations referencing the global fxx arrays as mentioned in this rather old, but still useful article. Finally, the Statement of Direction implies that version 4.0 will give us, 'Improved tabular forms, including support for validations...', so looking forward to that.
  • URL Tampering
  • And how this can be combated using the APEX built-in 'Session State Protection', see Dimitri's article or the official documentation.
  • Page Comments
  • Specifically, can these be mandated if this is a development standard? No, not currently but as John suggested this could be easily monitored through the APEX views. The issue also came up that the comments are right down the bottom of the page, which can lead to oversight. This question came up in the forums a couple of weeks ago and Patrick Wolf added a feature to the APEX Builder Plugin which addresses this issue by highlighting the 'Comments' link in yellow if there is a comment. Thank you Patrick!
  • Source Control
  • This keeps on cropping up at the moment. Basically if you are using a source control system such as CVS or SubVersion, what is the best strategy for managing the APEX application files? This can either be done at page level or application level and can be automated through use of the supplied command line tools 'ApexExport' and 'ApexExportSplitter'. APEX development team, how do you manage this?
  • JavaScript
  • A few JavaScript related questions came up. There are lots of libraries available in the APEX release that you can make use as a developer, the functions are unofficially documented by Carl Backstrom and according to the statement of direction will be officially documented and supported from 3.1, which is good news. Also what happens if a user has JavaScript turned off? Well, APEX can be used to build applications that meet accessibility requirements, but it requires some workarounds. See Sergio's article Application Express and Accessibility if you are interested in the steps involved. Peter also added that all client-side validations should be backup up with server-side / APEX validations as best practice.
  • Team Development
  • What is best practice for working on large projects with many developers? We mentioned an excellent article written by Ben Wootton, entitled, 'Best Practices for Oracle Application Express Collaborative Development' as an excellent reference point. This details use of page locks, page groups, use of Application Reports for monitoring, commenting changes, use of PL/SQL functions / procedures rather than embedding logic in page processes and lots more.

Dimitri and John after the session.

So that was about it, a very interesting and interactive discussion with loads of input from all the panel and much of the group, Jeremy doing a good job of keeping it all together. And it was great to meet Dimitri and Peter for the first time and catch up with John having met him on day 2.

Unfortunately I had to head back to Reading earlier than expected in the afternoon, so was unable to catch Dimitri's presentation. A very enjoyable day none the less and looking forward to next time!


Patrick Wolf said...

I wish I would have been there! Maybe next year :-)

Anthony Rayner said...


You would have definitely been more than welcome!!