OBUG APEX SIG 2011

The OBUG APEX SIG, held yesterday in Vilvoorde (near Brussels), was a smashing success. Due to the overwhelming amount of registrations, we even had to disappoint some people... Next year we should look for a venue that can accommodate more people!
Due to a long (at least, longer than I expected) driving time, I arrived during Anthony Rayner's presentation on APEX 4.1. It contained lots of demo's, especially the ones about the new error handling features where impressive: this is really a major improvement! The remarkable thing about the presentation itself was, he used a new feature of Websheets: Presentation Mode! Using this, you can (more or less easily) create presentations that contain real live data!
After the coffee break, iAdvise did a nice presentation on how to build (and use) Plug-ins. It was a smooth step-by-step approach on how to create a Plug-in. Well done guys!
The lunch was excellent, thanks to Oracle...
Right after that, John Scott did a presentation on OHS, EPG and APEX Listener. Too bad he ran a little out of time, so he couldn't address all the cool features of the AL. Nevertheless a very useful presentation when you have to decide which web server method you need - or better stated : when to use which one...because "it all depends" of course...
The next track I skipped to run through my own presentation once more - because it was the first time I would be doing "Done in 60 seconds - Creating Web 2.0 applications made easy". The presentation is all about the coolest feature (according to the OTN Forum poll) of APEX 4.0 : Dynamic Actions. I managed to do all demo's without any (major) flaw, so I think it all went pretty well....
Before the long trip home, I had some drinks and chats with the other attendees. It was good to see all those familiar (and new!) faces again.
Thanks to Oracle for hosting this event! But next time we should look for a venue somewhere in (the south of) The Netherlands...

Comments

Filtering in the APEX Interactive Grid

Remember Oracle Forms? One of the nice features of Forms was the use of GLOBAL items. More or less comparable to Application Items in APEX. These GLOBALS where often used to pre-query data. For example you queried Employee 200 in Form A, then opened Form B and on opening that Form the Employee field is filled with that (GLOBAL) value of 200 and the query was executed. So without additional keys strokes or entering data, when switching to another Form a user would immediately see the data in the same context. And they loved that. In APEX you can create a similar experience using Application Items (or an Item on the Global Page) for Classic Reports (by setting a Default Value to a Search Item) and Interactive Reports (using the APEX_IR.ADD_FILTER procedure). But what about the Interactive Grid? There is no APEX_IG package ... so the first thing we have to figure out is how can we set a filter programmatically? Start with creating an Interactive Grid based upon the good old Employ

apex_application.g_f0x array processing in Oracle 12

If you created your own "updatable reports" or your custom version of tabular forms in Oracle Application Express, you'll end up with a query that looks similar to this one: then you disable the " Escape special characters " property and the result is an updatable multirecord form. That was easy, right? But now we need to process the changes in the Ename column when the form is submitted, but only if the checkbox is checked. All the columns are submitted as separated arrays, named apex_application.g_f0x - where the "x" is the value of the "p_idx" parameter you specified in the apex_item calls. So we have apex_application.g_f01, g_f02 and g_f03. But then you discover APEX has the oddity that the "checkbox" array only contains values for the checked rows. Thus if you just check "Jones", the length of g_f02 is 1 and it contains only the empno of Jones - while the other two arrays will contain all (14) rows. So for

Stop using validations for checking constraints !

If you run your APEX application - like a Form based on the EMP table - and test if you can change the value of Department to something else then the standard values of 10, 20, 30 or 40, you'll get a nice error message like this: But it isn't really nice, is it? So what do a lot of developers do? They create a validation (just) in order to show a nicer, better worded, error message like "This is not a valid department". And what you then just did is writing code twice : Once in the database as a (foreign key) check constraint and once as a sql statement in your validation. And we all know : writing code twice is usually not a good idea - and executing the same query twice is not enhancing your performance! So how can we transform that ugly error message into something nice? By combining two APEX features: the Error Handling Function and the Text Messages! Start with copying the example of an Error Handling Function from the APEX documentation. Create this function

Roels Blog

Search This Blog