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Kscope18 flashback

After a few nights of good sleep (that means more than the average 4 to 5 hours at Kscope), it is time to sit back and evaluate what happened last week. I arrived on Thursday night before the event, just in time to catch Danny Bryant at the bar for "just one last beer" (I don't know how often I heard, and used, that phrase last week).
The whole Friday was filled with an all day Board Meeting, mainly discussing the future of ODTUG, a reception and a fine dinner. Since a couple of years, Saturday is the Community Service Day. This year, an impressive number of people showed up and were transferred to "Up Orlando", to make its easier for them to help the people that really need some help. All kinds of different activities were done, like cleaning, filling shelves, painting chairs etc.
 After that there is another tradition: bag stuffing. All those (about 1500) bags didn't get delivered with all those goodies in there! A number of volunteers created the most e…
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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 processing y…

Using multiple Authentication Schemes for your APEX application

Recently someone asked me how he could implement multiple authentication schemes for his APEX application. He would like to use (some kind of) Single Sign-on authentication and - as an alternative - an Application Express Authentication. The problem is ... you can only define one Authentication Scheme being "Current" for an application! So how can we solve this issue?

First, we need te be aware that multiple applications can share their authentication by using the same cookie. Thus if you specify "MYCOOKIE" as the Cookie Name in Application A as well as in Application B, you can switch from A to B and back without the need of logging in again. It doesn't matter what Authentication Scheme Type you are using!

Knowing this, we are halfway our solution. We need two Applications. One - the "real" application - using the Application Express Authentication, let's name this one "LAUNCHPAD". And another one using the Single Sign-on Authentication…

Dockerize your APEX development environment

Nowadays Docker is everywhere. It is one of the main components of Continuous Integration / Continuous Development environments. That alone indicates Docker has to be seen more as a Software Delivery Platform than as a replacement of a virtual machine.

However ...

If you are running an Oracle database using Docker on your local machine to develop some APEX application, you will probably not move that container is a whole to test and production environments. Because in that case you would not only deliver a new APEX application to the production environment - which is a good thing - but also overwrite the data in production with the data from your development environment. And that won't make your users very excited.
So in this set up you will be using Docker as a replacement of a Virtual Machine and not as a Delivery Platform.
And that's exactly the way Martin is using it as he described in this recent blog post. It is an ideal way to get up and running with an Oracle database …

Refresh selected row(s) in an Interactive Grid

In my previous post I blogged about pushing changed rows from the dabatase into an Interactive Grid. The use case I'll cover right here is probably more common - and therefore more useful!

Until we had the IG, we showed the data in a report (Interactive or Classic). Changes to the data where made by popping up a form page, making changes, saving and refreshing the report upon closing the dialog. Or by clicking an icon / button / link in your report that makes some changes to the data (like changing a status) and ... refresh the report.  That all works fine, but the downsides are: The whole dataset is returned from the server to the client - again and again. And if your pagination size is large, that does lead to more and more network traffic, more interpretation by the browser and more waiting time for the end user.The "current record" might be out of focus after the refresh, especially by larger pagination sizes, as the first rows will be shown. Or (even worse) while you…

Push changed rows to an Interactive Grid

For pushing changes from the database to the end user, the regular solution is using websockets. A change in a record is detected - using a trigger or using the CQN (Change Query Notification) feature - and a notification is send to a websocket server. That websocket server broadcasts the notification over a channel to all browsers that are tuned in to that websocket channel. Then the browser reacts to that notification, usually showing an alert or refreshing a report. This trick is described on multiple sites, just Google for "oracle apex websockets" or similar.

So back in the old days, we used that notification in the browser to refresh the (interactive) report. But along comes the Interactive Grid (IG). While he full-refresh mechanism still works for IG, an IG has also the option to refresh just one row.  So wouldn't it be awesome that just the changed row(s) get refreshed upon a change in the database, instead of the whole report? Can we do it ... yes we can!
First i…

A review of APEX World 2017 - Day 2

(You can read my impression of the first day here) After a short but good night sleep and an excellent breakfast, Mike Hichwa delivered his second keynote "RAD Challenge: Build a Real World application in 60 minutes”. Although he suffered from connection issues, Mike managed to wow the audience showing the new packaged app "Quick SQL” and  the new (currently Cloud-only) “Blueprint” option to create a new application. As JSON is not code (but just a collection of value-attribute pairs), it was really a no-code showcase!
Then it was parallel session time again and I went to see how Christian Rokitta would "Bootstrapify Universal Theme”. The message is: You don’t have to unsubscribe from the Universal Theme (and please don’t!) to create an application that looks totally different from the “regular” APEX applications.
Then I had to deliver my second presentation “Docker for Dummies”. It was aimed at people who might have heard of Docker but really have hardly a clue what …