ADF & JHeadstart
This category contains articles that relate not just to Java in the Oracle domain, but specifically to ADF (Application Development Framework, including ADF BC, ADF Binding and ADF Faces) and JHeadstart
In a recent article (http://technology.amis.nl/2013/04/02/adf-dvt-using-the-tree-map-visualization-component-to-compare-relative-sizes-and-distributions/) I discussed the ADF DVT Treemap component. This component visualizes data in such a way that comparisons between data values for different records and categories can quickly be made. The size of areas is a measure for some numerical value. As an additional dimension, the color of the areas can be used to identify groups (all members of the group having the same color) or to visualize a second numerical value (color can range for example from dark red to rich green depending on the net revenue per record).
This article describes the situation where we want to use multiple Treemap instances lined up. Each Treemap instance represents a collection of records on one or possibly multiple levels. Each instance can be drilled down into independently. And each instance can represent a different data set, even though we want to compare these data sets. Using a PanelGridLayout, it is easy to position multiple instances in a row or a grid. Using the inline style to scale the width and height of the Treemap instances, we can set the relative More >
The tree map component is one of those data visualization components that can tell an entire story through a simple picture. But of course that picture is anything but simple. And it is not even just a picture: it supports various forms of interaction such as drill down and popup. I had seen the Tree Map for the first time in demonstrations by Oracle Product Management. It seemed okay, but nothing very spectacular. Now, after having tried out the component for myself as well as studying the documentation, I may have to revise my initial opinion: it is actually a pretty cool and powerful component.
The Tree Map is used to present data values in a way that makes comparison easy, using two dimensions: (relative) size and color. The TreeMap uses containers for nodes with sizes relative to the numerical value associated with the nodes. Each node can have details and the container is presented with enclosed areas for each of the details. The size of these areas is proportional again to the value associated with the child node. All areas can be colored automatically – to create a pretty picture – or can be colored according to rules we can specify in order to have the colors also convey More >
One recurring theme in my articles on ADF has been that end users usually do not care about data. They are interested in getting information that helps them answer questions, make decisions and take actions. Data may be the foundation, but information is to be derived from the data. One way therefore to create applications that are more valuable to our end users is by preprocessing data and turning the data into information – or even into answers, proposed decisions and actions. A powerful way of turning data into information is through data visualization. By presenting data in a format that converts it to readily interpretable information, we help our users a lot. Bar charts, line graphs and other traditional charting formats are one of way visualizing data. The DVT library in ADF Faces goes far beyond traditional charts. It provides components such as the Gantt Chart, the Hierarchy Viewer, the Tree Map, Gauge and the TimeLine that help visualize data in natural, informative and attractive ways. This articles discusses the TimeLine component – introduced in ADF 11gR1 PS6 (220.127.116.11) in the Spring of 2013.
The TimeLine visualizes events against a time axis. It is as simple as that. More >
It looks like oracle made JDeveloper and ADF 18.104.22.168 available today. Perhaps not officially, but it can be downloaded. There are several interesting new components available. One of these is the codeEditor component which allows you to write code and have syntax highlighting. Not sure if I see a use case for this, but I’m in for a surprise. Also new are several DVT components such as the timeline, the sunburst and the treemap. And yes, hurray hurray, we now have the panelgridlayout available in 11gR1 ! Apparently there is also multi file upload. These are all very nice, but I’m also very enthusiastic about the return of the paging table.
This was the standard in 10g, but disappeared in 11g. It took 7 releases to get it back. In this post I describe how to use it. (more…)
Communication between taskflows and pages, beans and other components in ADF Faces applications is in many cases ideally implemented using contextual events. These events are published from a producer component – a page, taskflow or associated bean – and made available to all interested parties. Events are handed over by the ADF run time infrastructure to any registered consumer in the current scope. This includes any taskflow or enclosing page which has been configured as such. This publish/subscribe model helps achieve interaction and reuse in a decoupled way. I like the principle. I have applied it on several occasions. And today I needed it again in a WebCenter Portal application with custom ADF 11g components. And once again I could not remember exactly how to implement the contextual events, the publication and subscription. This article therefore is primarily for me – so I can quickly recall how to do this in similar subsequent situations. However, if it is useful to you too, that is even better!
The use case discussed in this article is as follows:
The section in the red rectangle is a taskflow that has been embedded as a region in the page. This taskflow has indicated More >
Recently the ADF SIG at AMIS organized an ADF DVT Speed Date. During this speed date six AMIS consultants presented their favorite DVT Component. In a series of blogposts we share the knowledge and findings. In this post you get introduced to the ADF DVT bubble graph. I will also show you how to make it interactive by clicking on the bubbles. The ability to make a graph interactive can be very usefull.
In the following bubble graph that we are going to create, the Life expectancy (y-axis), income a year (x-axis) and the population (bubble size) is shown. This in steps of 10 years, for the last 50 years (1970, 1980, 1990, 20000 and 2010). So for each country 5 bubbles are shown. The location of the bubble has a meaning; for example in Japan (grey) the life expectancy is the highest and in Pakistan the lowest (green). -Have developing countries moved forward their income? -Do they have longer lifes than 10, 20, 30, 40 or 50 years ago? A picture says more than thousand words – you can see it immediately in the graph.