Weblog for the AMIS Technology corner
Posts tagged placeholder data control
Suggestion for new type of ADF DVT (Data Visualization): the Delta Graph – to visualize relative changes integrated in a table layout
Jul 1st
I may have bored you before with stories about Data Visualization. It is one of my favorite topics. We deal in data. And visualization of data can help to increase the value of the data tremendously. Proper visualization provides quicker insight and reveals the true meaning of the numbers in an instant.
Newspapers frequently use graphics to illustrate the news reported in their articles. My morning paper has a broad palette of ways to represent numbers, trends, aggregates and incidents. It inspires me to mimic in my own toolset: ADF.
The other day, my newspaper printed the next figure that illustrates the changes in circulation for all Dutch newspapers – comparing the 1st quarter of 2011 with one year ago.
I quite like this presentation. It reveals a lot of information in an appealing way. I started wondering it this way of presenting changes would be easy to implement in ADF Faces applications. My first port of call obviously was the ADF DVT (Data Visualization Tags) library. However, it did not seem to offer a graph type that is very close to this presentation. Gauges appeared to come closest, but not quite there. And the inline-display inside table rows is related to spark charts, but again, it is not quite the same.
So I started playing with ‘ordinary’ ADF Faces and – using some CSS definitions – I came up with the following ADF Faces rendition of the Delta Graph:
In addition to the initial presentation, this ADF based version of the Delta Graph allows manipulation of the view, for example sorting the records by change or by current circulation:
Publishing resources exposed by ADF Data Control in RESTful services using RestLet and JDeveloper 11g
Oct 14th
The previous two articles on RESTful services using RestLet and developing in JDeveloper 11g – First Steps with RestLet 1.1RC2 in JDeveloper 11g – restful services 101 and Extending the RestLet application with support for POST/PUT to create and update Resources – used a static data set as source for the Resources. For real world services that will not be your typical scenario. Usually a business service hiding a persistence layer sitting on top of a database or wrapping a web service (RESTful or otherwise) is the more logical publisher of resources.
In this article, we will see how we can leverage ADF Model – Data Control & Data Bindings – to hook up such a business service. ADF Model publishes a Data Control for each Business Service it exposes. Through the Data Control applications can get access to data collections and operations acting on that data. For the application consuming the Data Control there should be no difference whether the underlying business service is an ADF BC application module connecting to a relational database, an EJB doing something similar, a web service published in the SOA of the organization or a RESTful service out there on the internet. That is at least the theory.
In this article, I will create a very simple Data Control, really nothing more than a mock object: a Placeholder Data Control. I will create a Thing data type and expose through the Placeholder Data Control a collection of Thing objects. The benefit of this approach is that we can take look at how ADF model can be used for providing the foundation for our RESTful services without the need for implementing a real business service. In a subsequent article we should find that the code we now write for the placeholder data control will work for ‘real’ data controls as well. 
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Building a repository of reusable ADF artefacts using ADF Libraries – for example: a reusable Placeholder Data Control
Sep 22nd
Reusability – and from there higher productivity and easier maintenance – is one of the key themes for ADF 11g. There are several important new concepts introduced in this new release, including Task Flows, Declarative Components, Page Templates and Page Fragments. It is of course one thing to create artefacts that are potentially reusable. It is quite another to organize those artefacts and make them available across projects and applications. And that is where the ADF Library comes in. It is the vehicle for packaging up fairly small scoped reusable elements in JAR files that are then made available in the Resource Catalog.
It turns out to be incredibly easy to create an ADF Library – and to reuse one. I will demonstrate that in this article, by turning a Placeholder Data Control that provides off line data binding opportunities for applications using DEPT and EMP. I have created a Placeholder Data Control with Department and Employee Data Types and sample data taken from the SCOTT schema. (see Some more details on ADF Placeholder Data Control (rebind component, master detail, load sample data from CSV file) for details on how to do that). Now I want to make that Placeholder Data Control available to any project I create where Dept/Emp data is useful and on line access to the database may not be available.
Note: it also makes sense for me to create an ADF Library with the HrmService ADF BC Application Module with the Entity and View Objects against the EMP and DEPT table that I so frequently use – and so frequently recreate because my personal reuse is organized so lamely! Read the rest of this entry »
