Welcome!

Eclipse Authors: Pat Romanski, Elizabeth White, Liz McMillan, David H Deans, JP Morgenthal

Related Topics: Eclipse, Adobe Flex

Eclipse: Article

A Runtime Integration Approach to Application Development

Plug-in Integrator Pattern

Figure 2 shows the basic components of the application. The UI of the application is simple, with a list/tree in the left panel to show different objects to be edited/viewed. On the right there is the editor/viewer container that is implemented using the Plug-in Integrator Pattern. The figure also shows component plug-ins to the container as tabs in the top. To view the object data as a graph, the view can be added statically to the container or loaded by the configurator, but depending on the requirements, View2 (the raw data view) and View3(Stats View) are added at a later time to augment the application functionality. View3 also needs to propagate a message to the View1, asking it to graph the new stats rather than just the data in object-1.

In this application different views for an object type are injected to the container at runtime and the existing components are used to provide new functionality as and when necessary by integrating plug-ins at runtime.   

 

The XML configuration file for the above application is shown in Annexure-2. 
 
The “containerConfiguration” element shows the basic container configuration with attributes for the container’s class and plug-in interface definitions. It also shows the plug-in components added to the container as child element “pluginComponent”.

As per the current application, the application ships with one plug-in component and the other two are injected to the container at a later time. Refer to Figure 3 for details.

In this application the container implements the Plug-in Integrator Pattern and hence there is only one component deployed to the container when it’s first shipped. In Figure 3 the first deployed XML is shown in bold face. Afterward the two other component views are added to the container and their definition gets added to the configuration accordingly as shown in Figure 3. For an application implementing this pattern, new views and functionality can be added dynamically without any need for compiling the application. In the next section we will see how these plug-in components can be integrated together to provide elegant user-friendly functionality.


To deploy an individual component to the container, it’s first required to implement the plug-in interface being exposed by the container. In the present case its mx.core.IUIComponent, so any Flex UI component can be plugged into the present container. Let’s consider the case of View3 and see how it has plugged into the container, initialized and hooked on to the View1 for graphing support during runtime, without changing any line of code or recompiling. The basic code listing for View3 is shown below.

<mx:Canvas>
<mx:Script>
<![CDATA[
public function initStatData(series:ArrayCollection,length:int):void
{//logic to come up with stats data from passed in ones
}
public function raiseGraphEvent():void{
  //raise the GRAPH EVT here
  dispatchEvent(new GrapphEvent("draw",dataProvider));
}
]]>
</mx:Script>
<mx:DataGrid >
  <mx:dataProvider>
    <mx:ArrayCollection id="dataProvider" />
  </mx:dataProvider>
  <mx:columns>
  <mx:DataGridColumn headerText="Sum" dataField="col1"/>
    …..
  </mx:columns>
</mx:DataGrid>
<mx:Label text="Stats for:Object"/>
<mx:Button label="GraphIt" click="raiseGraphEvent()"/>
</mx:Canvas>
 
The component shown above is pretty simple. It shows the basic mathematical operations on each row of the data series being represented by object-1. The function initStatData(..) is responsible for initializing the component, whereas the raiseGraphEvent() function raises an event having the new mathematical data series as the new data to draw a graph.

 <pluginComponent id="333345678" name="View3">
    <property name="label">
        <value><![CDATA[Stats View]]></value>
    </property>
    <moduleURL>/an/external/module/url-view3</moduleURL>
    <initParam type="funcHookup" bindToContainerProperty="editingObject">
        <selfFunction name="initStatsData">
            <arg name="param1">
               <objectRef srcObject="editingObject">
                    <evaluate expr="dataSeries"/>
               </objectRef>
            </arg>
            <arg name="param2">
               <objectRef srcObject="editingObject">
                <evaluate expr="dataSeries.processLength"/>
               </objectRef>
            </arg>                           
        </selfFunction>
    </initParam>               
</pluginComponent>

The listing above shows the configuration for the View3 plug-in component. The moduleURL is the location of the external module that contains the component plug-in. The component is initialized using the function hookup, calling the function “initStatData” with correct parameters being evaluated from the container’s editing object. As this component just raises an event of type GraphEvent and doesn't listen to any event by itself, there is no msgMap element required in the configuration. But this event will be tied in the View1 msgMap so that when this event is raised as a result of the “GraphIt” button click, the View1 can be refreshed with the graph drawing the mathematical result series. Let’s see the msgMap configuration of View1 to see how is that accomplished.

The msgMap configuration of View1 shows that it’s mapping View3 (referenced using the pluginCompid) GraphEvent with id “draw” to map to a handler for an event called “SomeEvent”.

<msgMap id="123456789" handler="event">
<srcExtentionPoint>
        <srcMsg id="draw" pluginCompid="333345678" type="somepkg::GraphEvent"/>
    </srcExtentionPoint>
    <destHandler>
        <destMsg id="graphIt" type="some.pkg::SomeEvent">
            <object clazz="some.pkg::SomeEvent">
                <property name="any">
                    <objectRef srcObject="srcEvent">
                        <evaluate expr="an.exp.to.get.req.data"/>
                    </objectRef>
                </property>
            </object>
        </destMsg>
    </destHandler>
</msgMap>

As in View3 the event raised was a different type ”GraphEvent”; it is needed to map that event to “SomeEvent” before propagating so that the handler function can handle it accordingly. It’s also possible to map the View3 GraphEvent to directly map to a handler in the View1 handler function; this can be achieved via the following msgMap configuration setting of View1.

 <msgMap id="123456789" handler="function">
<srcExtentionPoint>
        <srcMsg id="draw" pluginCompid="333345678" type="somepkg::GraphEvent"/>
    </srcExtentionPoint>
    <destHandler>
        <destHandlerFunc name="graphIthandlerFunc">
            <arg name="param1">
                <object clazz="some.pkg::SomeEvent">
                    <property name="any">
                       <objectRef srcObject="srcEvent">
                        <evaluate expr="an.exp.to.get.req.data"/>
                       </objectRef>
                    </property>
                </object>                       
            </arg>                   
        </destHandlerFunc>
    </destHandler>
</msgMap>

To come up with the msgMap setting, it’s required to go through the API documentation of both the components (View1 and View3). The configuration setting it just an easy way to integrate the functionality exposed by both components to come up with new features. The above example just shows the flexibility of the system when the Plug-in Integrator Pattern is used and the configuration is loaded externally and can be built and maintained with ease.

The concept of “initParam” to initialize a component based on a container variable to execute any component function to initialize state provides an efficient and easy way to glue components as plug-ins to the container. Also the msgMap to map any message or function callback from a source component to a message or function handler in the destination component provides the ultimate flexibility and integration points to build enterprise-ready products just by assembling already released and tested components at runtime.

This article is just an overview of the concepts being used in the Plug-in Integrator Pattern. The implementation of the pattern is already being done in Flex but needs some dedicated papers in that subject to explain.

Conclusion
The Plug-in Integrator Pattern discussed here is good for big projects being executed by enterprises where there are several groups working on separate projects of their own, but it becomes a breeze to integrate components from these already-released and tested projects to build new applications. It also provides a new dimension to Flex programming where the components being written once can be integrated in different projects without any change, thus promoting the “write once, deploy anywhere” concept. This pattern can readily be used in other platforms and programming languages to build flexible robust systems in no time. It also differs from the methodology used in already successful plug-in projects such as Eclipse and Firefox where the plug-ins are build on compile-time dependencies; this approach provides a way to build a plug-in based application with runtime aggregation.

More Stories By Indroniel Deb Roy

Indroniel Deb Roy works as an UI Architect for BlueCoat Systems.He has more than 10 years of development experience in the fields of J2EE and Web Application development. In his past he worked in developing web applications for Oracle, Novell, Packeteer, Knova etc. He has a passion for innovation and works with various Web2.0 & J2EE technologies and recently started on Smart Phone & IPhone Development.

More Stories By Alex Nhu

Alex Nhu works as a manager, UI Development at Packeteer Inc. He has more than 11 years of work experience designing and architecting complex server-side J2EE and XML applications. He loves developing Web applications with Flex now after getting a taste of developing UI using other RIA platforms.

Comments (1)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


@ThingsExpo Stories
A strange thing is happening along the way to the Internet of Things, namely far too many devices to work with and manage. It has become clear that we'll need much higher efficiency user experiences that can allow us to more easily and scalably work with the thousands of devices that will soon be in each of our lives. Enter the conversational interface revolution, combining bots we can literally talk with, gesture to, and even direct with our thoughts, with embedded artificial intelligence, whic...
Coca-Cola’s Google powered digital signage system lays the groundwork for a more valuable connection between Coke and its customers. Digital signs pair software with high-resolution displays so that a message can be changed instantly based on what the operator wants to communicate or sell. In their Day 3 Keynote at 21st Cloud Expo, Greg Chambers, Global Group Director, Digital Innovation, Coca-Cola, and Vidya Nagarajan, a Senior Product Manager at Google, discussed how from store operations and ...
In his session at 21st Cloud Expo, Carl J. Levine, Senior Technical Evangelist for NS1, will objectively discuss how DNS is used to solve Digital Transformation challenges in large SaaS applications, CDNs, AdTech platforms, and other demanding use cases. Carl J. Levine is the Senior Technical Evangelist for NS1. A veteran of the Internet Infrastructure space, he has over a decade of experience with startups, networking protocols and Internet infrastructure, combined with the unique ability to it...
It is of utmost importance for the future success of WebRTC to ensure that interoperability is operational between web browsers and any WebRTC-compliant client. To be guaranteed as operational and effective, interoperability must be tested extensively by establishing WebRTC data and media connections between different web browsers running on different devices and operating systems. In his session at WebRTC Summit at @ThingsExpo, Dr. Alex Gouaillard, CEO and Founder of CoSMo Software, presented ...
Gemini is Yahoo’s native and search advertising platform. To ensure the quality of a complex distributed system that spans multiple products and components and across various desktop websites and mobile app and web experiences – both Yahoo owned and operated and third-party syndication (supply), with complex interaction with more than a billion users and numerous advertisers globally (demand) – it becomes imperative to automate a set of end-to-end tests 24x7 to detect bugs and regression. In th...
"Space Monkey by Vivent Smart Home is a product that is a distributed cloud-based edge storage network. Vivent Smart Home, our parent company, is a smart home provider that places a lot of hard drives across homes in North America," explained JT Olds, Director of Engineering, and Brandon Crowfeather, Product Manager, at Vivint Smart Home, in this SYS-CON.tv interview at @ThingsExpo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
"Cloud Academy is an enterprise training platform for the cloud, specifically public clouds. We offer guided learning experiences on AWS, Azure, Google Cloud and all the surrounding methodologies and technologies that you need to know and your teams need to know in order to leverage the full benefits of the cloud," explained Alex Brower, VP of Marketing at Cloud Academy, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clar...
"MobiDev is a software development company and we do complex, custom software development for everybody from entrepreneurs to large enterprises," explained Alan Winters, U.S. Head of Business Development at MobiDev, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
SYS-CON Events announced today that CrowdReviews.com has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5–7, 2018, at the Javits Center in New York City, NY. CrowdReviews.com is a transparent online platform for determining which products and services are the best based on the opinion of the crowd. The crowd consists of Internet users that have experienced products and services first-hand and have an interest in letting other potential buye...
"There's plenty of bandwidth out there but it's never in the right place. So what Cedexis does is uses data to work out the best pathways to get data from the origin to the person who wants to get it," explained Simon Jones, Evangelist and Head of Marketing at Cedexis, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
"IBM is really all in on blockchain. We take a look at sort of the history of blockchain ledger technologies. It started out with bitcoin, Ethereum, and IBM evaluated these particular blockchain technologies and found they were anonymous and permissionless and that many companies were looking for permissioned blockchain," stated René Bostic, Technical VP of the IBM Cloud Unit in North America, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Conventi...
WebRTC is great technology to build your own communication tools. It will be even more exciting experience it with advanced devices, such as a 360 Camera, 360 microphone, and a depth sensor camera. In his session at @ThingsExpo, Masashi Ganeko, a manager at INFOCOM Corporation, introduced two experimental projects from his team and what they learned from them. "Shotoku Tamago" uses the robot audition software HARK to track speakers in 360 video of a remote party. "Virtual Teleport" uses a multip...
SYS-CON Events announced today that Telecom Reseller has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5-7, 2018, at the Javits Center in New York, NY. Telecom Reseller reports on Unified Communications, UCaaS, BPaaS for enterprise and SMBs. They report extensively on both customer premises based solutions such as IP-PBX as well as cloud based and hosted platforms.
SYS-CON Events announced today that Evatronix will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Evatronix SA offers comprehensive solutions in the design and implementation of electronic systems, in CAD / CAM deployment, and also is a designer and manufacturer of advanced 3D scanners for professional applications.
Leading companies, from the Global Fortune 500 to the smallest companies, are adopting hybrid cloud as the path to business advantage. Hybrid cloud depends on cloud services and on-premises infrastructure working in unison. Successful implementations require new levels of data mobility, enabled by an automated and seamless flow across on-premises and cloud resources. In his general session at 21st Cloud Expo, Greg Tevis, an IBM Storage Software Technical Strategist and Customer Solution Architec...
To get the most out of their data, successful companies are not focusing on queries and data lakes, they are actively integrating analytics into their operations with a data-first application development approach. Real-time adjustments to improve revenues, reduce costs, or mitigate risk rely on applications that minimize latency on a variety of data sources. In his session at @BigDataExpo, Jack Norris, Senior Vice President, Data and Applications at MapR Technologies, reviewed best practices to ...
An increasing number of companies are creating products that combine data with analytical capabilities. Running interactive queries on Big Data requires complex architectures to store and query data effectively, typically involving data streams, an choosing efficient file format/database and multiple independent systems that are tied together through custom-engineered pipelines. In his session at @BigDataExpo at @ThingsExpo, Tomer Levi, a senior software engineer at Intel’s Advanced Analytics gr...
When talking IoT we often focus on the devices, the sensors, the hardware itself. The new smart appliances, the new smart or self-driving cars (which are amalgamations of many ‘things’). When we are looking at the world of IoT, we should take a step back, look at the big picture. What value are these devices providing? IoT is not about the devices, it’s about the data consumed and generated. The devices are tools, mechanisms, conduits. In his session at Internet of Things at Cloud Expo | DXWor...
Everything run by electricity will eventually be connected to the Internet. Get ahead of the Internet of Things revolution. In his session at @ThingsExpo, Akvelon expert and IoT industry leader Sergey Grebnov provided an educational dive into the world of managing your home, workplace and all the devices they contain with the power of machine-based AI and intelligent Bot services for a completely streamlined experience.
SYS-CON Events announced today that Synametrics Technologies will exhibit at SYS-CON's 22nd International Cloud Expo®, which will take place on June 5-7, 2018, at the Javits Center in New York, NY. Synametrics Technologies is a privately held company based in Plainsboro, New Jersey that has been providing solutions for the developer community since 1997. Based on the success of its initial product offerings such as WinSQL, Xeams, SynaMan and Syncrify, Synametrics continues to create and hone inn...