Understanding the JSF Lifecycle and ADF Optimized Lifecycle
- by Steven Davelaar
While coaching ADF development teams over the years, I have noticed that many developers lack a basic understanding of Java Server Faces, in particular the JSF lifecycle and how ADF optimizes this lifecycle in specific situations. As a result, ADF developers who are tasked to build a seemingly simple ADF page, can get extremely frustrated by the -in their eyes- unexpected or unlogical behavior of ADF. They start to play with the immediate property and the partialTriggers property in a trial-and-error manner. Often, they play with these properties until their specific issue is solved, unaware of other more severe bugs that might be introduced by the values they choose for these properties.
So, I decided to submit a presentation for the UKOUG entitled "What you need to know about JSF to be succesful with ADF". The abstract was accepted, and I started putting together the presentation and demo application. I built up a demo application step-by-step, trying to cover the JSF-related top issues and challenges I encountered over the years in a simple "Hello World" demo. This turned out to be both a very time-consuming and very interesting journey. I had never thought I would learn so much myself in preparing this presentation. I never thought I would end up with potentially controversial conclusions like "Never set immediate=true on an editable component". I did not realize the sometimes immense implications of the ADF optimized lifecycle beforehand. I never thought that "Hello World" demo's could get so complex. But as I went on I was confident this was valuable material, even for experienced ADF developers with a good understanding of JSF.
When I finished, I realized the original title and abstract was misleading, as was the target audience. Yes, it was covering the JSF lifecycle, but no other aspects of JSF you need to know for ADF development. Yes, it was covering some JSF basics as mentioned in the abstract, but all in all it had become a pretty advanced presentation. At the same time, the issues discussed are very common, novice ADF developers might easily run into them while building their first pages. I ran out of time, so I decided to just present what I had, apologizing at the beginning for the misleading title, showing a second slide with a better title "18 invaluable lessons about ADF-JSF interaction". I think the presentation was well received overall, although people who don't like it or don't understand it, usually don't come and tell you afterwards....
I am still struggling with the title, for this blog post I used yet another title, anyway, you can download the presentation-that-still-lacks-a-good-title here. The finished JDev 11.1.1.6 demo app can be downloaded here. The 18 lessons mentioned in the presentation are summarized here. As mentioned on the last slide, print out the lessons, and learn them by heart, I am pretty sure it will save you lots of time and frustration!