Posts tagged adf faces
Notifying ADF applications of database changes – fast and lean using Active Data Service for Server to Client Push – Part Two
0Yesterday I wrote that in two articles, I would demonstrate how we can ensure that changes in the database – new, changed or deleted data – can rapidly be reflected in ADF based user interfaces running in browsers. This story involves a two-step push-mechanism: push from database to middle tier and push from middle tier to browser. For the former – discussed in Notifying ADF applications of database changes – fast and lean using Database Query Result Change Notification – Part One – we will use the Oracle Database (and JDBC Driver) feature Query Result Change Notification and for the latter we leverage the Active Data Service in ADF Faces. The latter – server to browser push – is the topic of this second part. It will hook into where the first part took us (so you are advised to first read part one) and take the changes the database notifies us all the way up into the user interface.
A sketch of the architecture of the application we will create in this article looks like this:
The two push steps are marked with the green ellipses. The red box indicates the area under scrutiny in this article.
Using custom functions in EL expressions in JSF 1.x
1EL expressions are one of the main driving forces for JavaServer Faces. Most dynamic characteristics of pages and widgets are governed by EL expressions. In JSF 1.x, there are some limitations for EL expressions that can at times be a little frustrating. One of the limitations is the fact that no custom functions or operators can be used in EL expressions. Quite some time ago, I wrote this article – http://technology.amis.nl/blog/622/how-to-call-methods-from-el-expressions-pre-jsp-20-trick-for-jsps-with-jstl – to demonstrate a trick for using a Map interface implementation to access custom functionality from EL expression after all.
However, things can even be better. Rather than jumping through the somewhat elaborate hoops of implementing the Map and consructing complex EL expressions, there are two other approaches. One is to create a custom EL Resolver can configure it in the faces-config.xml. Another is discussed in this article. It involves registering custom Java methods as eligible for use in EL expressions. And that really makes life a lot easier. It allows us to create EL expressions such as:
#{cel:concat (cel:upper( bean.property), cel:max(bean2.property, More >
ADF Gold Nuggets – from Oracle Open World's ADF Enterprise Methodology Group Super Sunday
0Sunday 2nd of October 2011 saw, in the prelude to the Oracle Open World conference, the ADF Enterprise Methodology Group’s Super Sunday. Six valuable presentations on planning, designing, building and improving ADF applications by experienced ADF specialists. In front of an audience of over 150.
Interest in ADF seems higher than ever – with an increasing number of organizations starting with BPM, WebCenter or/and ADF proper – and many of them interested in having their approach confirmed as well as finding new and better ways to address certain challenges.
I presented the ADF Gold Nuggets presentations – on valuable yet often unknown or underestimated features and functions in ADF. Going from very small, single property features to large areas and event architectural concepts, I took the audience on a somewhat strange ride – that most seemed to enjoy though. I have put my slides on Slideshare, accessible below.
Leveraging HTML 5 Navigator API to show the browser's current location on an ADF Faces 11gR2 Thematic Map component
0This article demonstrates how, through a bit of JavaScript interacting with the HTML 5 Navigator API, some more JavaScript using the ADF Faces Rich Components API and the ADF Faces 11gR2 Thematic Map component, it becomes quite easy to not only learn about the end user’s physical location but to also show that location on a map – and along with it typically the nearest branches of your company.
The page developed in this article will essentially look as is shown in the next figure:
The HTML 5 Navigator API is available in most modern browsers – including Firefox 3.5+, Chrome 5.0+, Safari 5.0+, IE 9, iPhone 3.0+ and Android 2.0+. Note that the user should explicitly allow an application to learn about his or her location – and not get a handle on it just like that.
See Dive into HTML 5 for more details: http://diveintohtml5.org/geolocation.html
Dropping trees
There are many ways to reassign employees. You, as a programmer or DBA could, for instance, write an update statement to do that. But let’s say that you don’t want to lose your friends at the HR department. They want you to build a real flashy GUI to achieve the very same functionality. Ooops. No more lunch breaks for a week or two, because you planned this task to take only half an hour (the time that writing an update statement takes, if you type very slowly and test it intensively). ADF 11g provides you with two very handy features. First there’s the tree which is not new, but enhanced. Second there’s drag and drop functionality. Here is a way to use those two into a powerful combination. (more…)
Recent Comments