Welcome!

Java IoT Authors: Pat Romanski, Zakia Bouachraoui, Elizabeth White, Mehdi Daoudi, Liz McMillan

Related Topics: Java IoT

Java IoT: Blog Feed Post

BIRT Crosstab Scripting

The BIRT crosstab element offers onPrepare, onCreate and onRender hooks as well

BIRT supplies scripting hooks for just about every report element in the palette. You can generally implement an onPrepare, onCreate, and onRender event handler for each of these report items. The onPrepare event fires before data is retrieved and allows you to change the design for a specific report item. The onCreate event fires when the report item is being created by the report engine’s generation task. The onRender event fires when the report item is being rendered by the report engine’s render task. These events and example are described on the BIRT website.

Some report items offer more event hooks. For example a chart item actually has over thirty event hooks that allow total customization of the chart generation and presentation phases. As a side note, all chart scripts fire during the report engine’s render task. This does not mean the database is hit at render time though. The report engine will cache the data for a chart in memory or in a report document, depending on what task type is being used to run and render the report.

The BIRT crosstab element offers onPrepare, onCreate and onRender hooks as well. These events are fired both for the crosstab as a whole and for each individual cell in the crosstab. When firing events for cells, these are processed top to bottom and left to right. Handlers can be written using the script tab at the bottom of the report design view. BIRT also supplies an event adapter to allow you to write these events in Java as well.

As an example script, you can modify the crosstab in the onPrepare like:

function onPrepareCrosstab( crosstab, reportContext )
{
var coldim = crosstab.getColumnLevels().get(0);
coldim.removeAllFilterConditions();
crosstab.getStyle().setFontFamily("Arial");
crosstab.getStyle().setFontSize("8");

}

This script removes filters from the first column level and sets some font information. Some of the more interesting capabilities are available when using the onCreateCell event hook. For example consider the following script.

function onCreateCell( cellInst, reportContext )
{

//Can reference cells by type or id - valid types "header" or "aggregation"
if( cellInst.getCellType() == "header" ) {
//Get data values see binding tab on crosstab
//if( cellInst.getDataValue("PRODUCTLINE") == "Planes" ){
if( reportContext.evaluate("dimension['ProductGroup']['PRODUCTLINE']") == "Planes" ){
cellInst.getStyle().setBackgroundColor("#FF0000");
cellInst.getStyle().setFontSize("12");
}else{
//Set the rest to yellow
cellInst.getStyle().setBackgroundColor("#FFFF00");
cellInst.getStyle().setFontSize("12");
}

}
//refer to crosstab header
if( cellInst.getCellID() == 167){
cellInst.getStyle().setBackgroundColor("Orange");
}
if( cellInst.getCellType() == "aggregation"){
//Can refernce value using getDataValue or
if( cellInst.getDataValue("PRODUCTLINE") == "Planes" ){
//set color to bluegray
cellInst.getStyle().setBackgroundColor("RGB(169,170,226)");
}
//by using reportContext.evaluate
//if( reportContext.evaluate("measure['amount']") > 50000 ){
if( cellInst.getDataValue("amount_DateGroup/quarter_ProductGroup/PRODUCTLINE") > 50000 ){
cellInst.getStyle().setBackgroundColor("Green");
cellInst.getStyle().setColor("White");
}
}
}

The onCreateCell script is passed the reportContext and an instance of the cell. The cellInst object has several methods that can be used to determine which cell is currently being processed. You can call getCellType() which will return header or aggregation. In the following image all cells in the red box will return aggregation and all others will return header.

You can also call getCellID() which will return the specific element id that your crosstab uses for that cell.


In this example the getCellID call will return 160 every time this cell is created. This can be useful when you are trying to determine if you have a new row or column in your crosstab. If this is the innermost header element then this cell will be created for every new row/column. The only drawback to this approach is that if the crosstab is in a library or you copy and paste it, the cell ids will change.

Once you know the cell you are currently processing you generally want to access the data, to make some script decision. To do this you have a couple of choices. You can call the getDataValue method on the cell instance or use the reportContext.evaluate method. When using the getDataValue method, the value you need to refer to is the data binding column name set on the crosstab item. For example:

cellInst.getDataValue("PRODUCTLINE") == "Planes"

refers to the PRODUCTLINE data binding. Also note that this is the value of the column as this particular cell is being processed.

You can also use the reportContext.evaluate method, which allows you to build an expression and bypass the binding. For example:
if( reportContext.evaluate("dimension['ProductGroup']['PRODUCTLINE']") == "Planes" )

Essentially returns the same value as the previous getDataValue(“PRODUCTLINE”) method. This is because the PRODUCTLINE data binding has:

dimension['ProductGroup']['PRODUCTLINE']

As it’s expression. This example references a particular dimension of the cube. You can reference cube measures as well.

reportContext.evaluate("measure['amount']")

As with the column binding this will return the value for the specific cell you are currently processing.

In the script posted at the top of this post, we use the cell instance object to set specific styling based on the values of various column bindings. This is done using the getStyle method.

cellInst.getStyle().setBackgroundColor("Green");
cellInst.getStyle().setColor("White");

Using this method is no different than other BIRT report items.

Using these methods and the reportContext you can write some very sophisticated scripts. For example you can store all the quantities ordered where the product line is ships to a global variable using a script similar to this:

if( cellInst.getCellType() == "aggregation" && cellInst.getCellID() == 151){
if( cellInst.getDataValue("PRODUCTLINE") == "Ships" ){
importPackage(Packages.java.lang );
var cur = cellInst.getDataValue("amount_DateGroup/quarter_ProductGroup/PRODUCTLINE");
if( reportContext.getGlobalVariable("totalplanes")==null){
reportContext.setGlobalVariable("totalplanes", new Double(Double.parseDouble(cur)) );
}else{
var oldcnt = reportContext.getGlobalVariable("totalplanes");
reportContext.setGlobalVariable("totalplanes", new Double(Double.parseDouble(oldcnt) + Double.parseDouble(cur)));
}
}
}


This value can then be referenced within the same crosstab or later in the report. For example the following expression for a text item can be used.

<VALUE-OF format="#,##0.00">reportContext.getGlobalVariable("totalplanes");</VALUE-OF>

This example can also be implemented in Java. In the attached link the report will contain two crosstabs. One where the code is done in JavaScript and the other uses an event handler written in Java, which is also attached.

The example report output is presented below.



The examples are available at Birt-Exchange.

More Stories By Jason Weathersby

Jason Weathersby is a member of the extended BIRT development team at Actuate Corporation and has backgrounds in both computer science and technical writing. He has many years experience in technical consulting, training, writing, and publishing about reporting, business intelligence tools, and database technologies.

IoT & Smart Cities Stories
In an age of borderless networks, security for the cloud and security for the corporate network can no longer be separated. Security teams are now presented with the challenge of monitoring and controlling access to these cloud environments, at the same time that developers quickly spin up new cloud instances and executives push forwards new initiatives. The vulnerabilities created by migration to the cloud, such as misconfigurations and compromised credentials, require that security teams t...
AI and machine learning disruption for Enterprises started happening in the areas such as IT operations management (ITOPs) and Cloud management and SaaS apps. In 2019 CIOs will see disruptive solutions for Cloud & Devops, AI/ML driven IT Ops and Cloud Ops. Customers want AI-driven multi-cloud operations for monitoring, detection, prevention of disruptions. Disruptions cause revenue loss, unhappy users, impacts brand reputation etc.
The platform combines the strengths of Singtel's extensive, intelligent network capabilities with Microsoft's cloud expertise to create a unique solution that sets new standards for IoT applications," said Mr Diomedes Kastanis, Head of IoT at Singtel. "Our solution provides speed, transparency and flexibility, paving the way for a more pervasive use of IoT to accelerate enterprises' digitalisation efforts. AI-powered intelligent connectivity over Microsoft Azure will be the fastest connected pat...
CloudEXPO has been the M&A capital for Cloud companies for more than a decade with memorable acquisition news stories which came out of CloudEXPO expo floor. DevOpsSUMMIT New York faculty member Greg Bledsoe shared his views on IBM's Red Hat acquisition live from NASDAQ floor. Acquisition news was announced during CloudEXPO New York which took place November 12-13, 2019 in New York City.
As you know, enterprise IT conversation over the past year have often centered upon the open-source Kubernetes container orchestration system. In fact, Kubernetes has emerged as the key technology -- and even primary platform -- of cloud migrations for a wide variety of organizations. Kubernetes is critical to forward-looking enterprises that continue to push their IT infrastructures toward maximum functionality, scalability, and flexibility. As they do so, IT professionals are also embr...
BMC has unmatched experience in IT management, supporting 92 of the Forbes Global 100, and earning recognition as an ITSM Gartner Magic Quadrant Leader for five years running. Our solutions offer speed, agility, and efficiency to tackle business challenges in the areas of service management, automation, operations, and the mainframe.
@CloudEXPO and @ExpoDX, two of the most influential technology events in the world, have hosted hundreds of sponsors and exhibitors since our launch 10 years ago. @CloudEXPO and @ExpoDX New York and Silicon Valley provide a full year of face-to-face marketing opportunities for your company. Each sponsorship and exhibit package comes with pre and post-show marketing programs. By sponsoring and exhibiting in New York and Silicon Valley, you reach a full complement of decision makers and buyers in ...
While the focus and objectives of IoT initiatives are many and diverse, they all share a few common attributes, and one of those is the network. Commonly, that network includes the Internet, over which there isn't any real control for performance and availability. Or is there? The current state of the art for Big Data analytics, as applied to network telemetry, offers new opportunities for improving and assuring operational integrity. In his session at @ThingsExpo, Jim Frey, Vice President of S...
In his keynote at 18th Cloud Expo, Andrew Keys, Co-Founder of ConsenSys Enterprise, provided an overview of the evolution of the Internet and the Database and the future of their combination – the Blockchain. Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life settl...
Two weeks ago (November 3-5), I attended the Cloud Expo Silicon Valley as a speaker, where I presented on the security and privacy due diligence requirements for cloud solutions. Cloud security is a topical issue for every CIO, CISO, and technology buyer. Decision-makers are always looking for insights on how to mitigate the security risks of implementing and using cloud solutions. Based on the presentation topics covered at the conference, as well as the general discussions heard between sessio...