Liferay DXP/7 BLADE CLI Introduction and Its Commands

Liferay DXP/7 have exciting features and one of the major architectural change is to support OSGi modularity framework.

Follow the below article to know more information about Liferay DXP/7 Modularity introduction.

Liferay 7 / DXP Modularity Introduction

Now Liferay DXP/7 Application development through OSGi bundles and it has followed the OSGi specification.

Follow Liferay DXP/7 Tutorial to get more information.

Liferay 7 / DXP Tutorial

Liferay DXP/7 introduced module development tool called BLADE CLI. BLADE is a Command Line Interface have set of commands to create Liferay DXP/7 modules and its deployment into the Liferay OSGi run time environment.

Bootstrapped Liferay Advanced Development Environment shortly we call it as BLDAE. It is very easy to install and very flexible to use and create Liferay Modules.

BLADE have implemented based on Gradle build tool. Behind the scene, BLADE uses the Bndtools framework to create and deploy OSGi bundles.  Finally, we can say BLADE is based on the Gradle flavor Bndtools.

OSGi Bndtools

BLADE have provided the human readable commands to create Liferay modules. BLADE consist of several Module Templates to create Liferay 7 Application modules like portlet module, hook module and theme module. It also have commands to access sample projects and deploy into OSGi runtime.

 BLADE tools have commands to create Liferay 7 module and we can use any Development IDE to edit the code then deploy through BLADE CLI commands. Installation of BLADE tool and Module creation process will be explained in the future articles. Once we installed the BLADE, we can issue the predefined commands to create and deploy the modules.

The following are the set of BLADE CLI commands its description.

deploy:

Deploy commands will build and deploy the modules into Liferay OSGi environment. Usually deploy commands works similar to previous liferay MAVEN deploy but it’s in OSGi way. It will compile, build and package the module and place the module jar file into Liferay Portal deploy directory. Once the module jar file place in deploy directory then Liferay hot deploy process will handle subsequent steps to make the available of module to end user.

convert:

Convert previous Plugins SDK plugins to OSGi modules. Usually Liferay 7 have concept called Liferay Workspace.  It convert Plugins project to Workspace project based on Gradle.

As we know that Liferay DXP/7 based on OSGi and all Liferay 7 application, make it as modules. However, we already have Plugin Environment to develop Liferay previous versions applications so convert toll make it plugins to modules.

create:

Create command used to create new Liferay Application Module based on available module templates. BLADE has provided several module templates to create different types such as portlet, hook and them modules. These commands have several option so choose appropriate template.

gw:

gw is Gradle Wrapper on top of Gradle build to make work easier for developer to run Gradle build commands.

init:

Liferay has introduced Liferay Workspace to manage the Liferay modules and it’s easy to shift one place to other place. Init command will initialize the Liferay Workspace it means it will create directory structure to accommodate modules, related properties and liferay portal server instance.  All will be created once we use init command.

install:

This command install a liferay bundle into Liferay OSGi runtime environment. Bundle is packaged OSGi jar file, which run in OSGi runtime.

help:

Help commands will shows help information like list of available commands and its options.

open:

Open command open or import file in Liferay IDE and open project as well.

samples:

Samples project generated sample projects in Liferay Workspace. Liferay have provided sample project for the developers to understand more about Liferay module development.

Sample command will access those samples from repository and downloaded into local Liferay Workspace. We can edit, deploy and test the sample modules.

server:

This command start Liferay Portal Server Instance, which reside in Liferay Workspace bundle directory.

sh:

Sh command connect to Apache Gogo shell console to manage OSGi bundles which are available in OSGi runtime.

Apache Felix Gogo Shell Introduction

Access Felix Gogo Shell in Liferay 7

Access Felix Gogo Shell in Liferay 7 from PuTTY Terminal

update:

Update command will update to latest versions when new version is available.

version:

It will display BLADE CLI version information.

Author

Meera Prince

Liferay Contributor of the Year 2016
Liferay Top Contributor Award Winner 2015

Liferay Contributor of the Year 2014

Liferay Top Contributor Award Winner 2013

http://www.liferaysavvy.com 

Read More

OSGi Whiteboard Design Pattern

Design patterns plays important role in the Software Development. It will define the reusable implementation to the commonly occurred problems. Usually in software development, we can see same problem repeatedly coming in the applications. To address these common problems, expert people came up with solution called design patterns. Design patterns define the solution so that we can implement solution to address the the common problems.

Follow Liferay DXP/7 Tutorial to get more information.

Liferay 7 / DXP Tutorial

Whiteboard Design pattern is commonly and wide used pattern in OSGi implementations. OSGi Service Registry implemented on White Board Design Patter.

Liferay 7 / DXP have used OSGi Declarative Services (DS) to implements Liferay application modules. It is good to know White Board design pattern and Service Registry. It will give more idea about component services and its working.

When we work with Declarative Service Framework, bundle have several components and these components depends on other components.

Usually component have services and these services shared among other components. Service Registry manage the services registration information and its dependency service information. It will manage services and its references information.

To manage these things OSGi have Service Registry that is based on Whiteboard Design Pattern.

White Board Design pattern will provide the mechanism to register the different component services and the dependency component can easily find it reference service based on their needs. Whenever new service implementation register with Service Registry then dependency will get to know the information so that it can find appropriate dependency service.

Assume Component C1 have service S1 and perform certain task, it needed other service it means service S1 depends on other component services.

Assume S1 service can have several option that can perform task, it means several component provides their services to S1 and S1 can choose any of that service to full fill the requirement. Now S1 have options like C2 component Service S2 and C3 Components Service S3.

To provide these dependency service information or reference service information we need other component so that S1 service can identify its dependent service. To provide this king information we need other component called Whiteboard or Service Registry.

When the component is activated, all the services are register with Whiteboard / Service Registry.

Now C1 component Service S1 can identify, it’s required dependent service from the Whitboard / Service Registry to complete or perform the task.

Here S1 have several option, it can choose any of the service based on its requirement. S1 will use some additional properties to identify the required service at the point of the time. Such a way whiteboard design pattern have used in OSGi to implement Service Registry.

Service Registry is key component in the OSGi implementation and OSGi Declarative Service have used Service Registry to provide dependency mechanism among the component services.  OSGi Declarative Service is core framework to develop OSGi components and its services.

Author

Meera Prince

Liferay Contributor of the Year 2016
Liferay Top Contributor Award Winner 2015

Liferay Contributor of the Year 2014

Liferay Top Contributor Award Winner 2013

http://www.liferaysavvy.com 

Read More

Liferay 7 / DXP Modularity Introduction

Liferay 7 /DXP is new release from Liferay Inc. Liferay 7 / DXP came up with new architecture based development that is OSGi.

As we know OSGi (Open Services Gateway Initiative) is Dynamic Component Development for Java platform. Its modular framework, where we can compose the application into several module and the modules communicate each other.  Liferay 7 / DXP have OSGi support so we can develop liferay applications as OSGi modules.  Modularity is interesting feature and have many capabilities to make application into several modules.

Follow the bellow articles to know more about OSGi

http://www.liferaysavvy.com/2015/12/open-services-gateway-initiative-osgi.html

http://www.liferaysavvy.com/2016/11/open-source-gateway-initiative-osgi.html

http://www.liferaysavvy.com/2016/11/access-felix-gogo-shell-in-liferay-7.html

http://www.liferaysavvy.com/2017/08/osgi-architecture.html

http://www.liferaysavvy.com/2016/10/apache-felix-introduction.html

Interesting features of OSGi

Reduce the complexity and make the application sampler

Easy Deployment of applications

Reasonability of the components and modules

Easy version management

Cross platform support we can run anywhere

Widely used platform now a days.

When we consider all above interesting features OSGi promising platform to deliver many interesting capabilities.

Liferay 7 / DXP have used OSGi modularity features to build and develop the Liferay 7/ DXPApplications.

OSGi specification available in two popular implementations such as Apache Felix and Eclipse Equinox.

http://www.liferaysavvy.com/2016/10/apache-felix-introduction.html

http://www.liferaysavvy.com/2016/11/access-felix-gogo-shell-in-liferay-7.html

Liferay 7 have used both implementation capabilities to strengthen the Liferay Modular Application development.

Traditional Web application development have application servers, which runs the web applications. It means, we will develop applications based on web application standards using some J2EE Web application frameworks. We will package these applications as WAR files and deploy into the Application Servers. This is basic web application development and runs the applications.

Whereas OSGi environment have OSGi container to run the OSGi applications.
OSGi applications can call it as OSGi bundles. OSGi bundles is JAR file, which consist of Java and other configuration files. These bundle developments follow the OSGi specification so that it can run in OSGi containers.

When we are talking about OSGi bundles, we use Component terminology many times.  Component is piece of code, which runs independently and deliver some reusable feature or task.

OSGi application composed of several components and these components are talk each other and all together deliver complex feature or task.

We package the group of components as bundle. Bundles is an OSGi application based on OSGi specification and runs in OSGi containers. Interesting feature of OSGi is application composed into small components.  

OSGi have other interesting artifact called OSGi Service Registry, which manage the component and its service registration and manage the references. OSGi component dependency management controlled via OSGi service registry. OSGi service registry implemented by OSGi Declarative Services and shorty we call it as DS.

http://www.liferaysavvy.com/2017/09/osgi-declarative-services-ds.html

http://www.liferaysavvy.com/2017/10/differences-between-liferay-7-dxp-and.html

We also have other implementation called Apache Blueprint, which is similar to DS.

http://www.liferaysavvy.com/2017/10/apache-blueprint-introduction.html

Liferay 7 /DXP can use both implementation while develop Liferay Application Modules.

Structure of OSGi Module

As per OSGi module development, we have following pieces in the application.

Service API: Service API bundles container the all service interfaces

Service Provider: Service provider bundles provide the implementation for the interfaces which definer in the Service API

Service Client: It will consume the component services.

http://www.liferaysavvy.com/2017/08/osgi-dependency-management.html

http://www.liferaysavvy.com/2017/09/osgi-dependency-management-example.html

Liferay 7 / DXP module development follows the same structure while developing the Liferay 7/DXP application bundles.

Structure of a Modular App in Liferay 7 / DXP

As per OSGi, we can break the application into several bundles. Same way Liferay 7 / DXP have several bundles/modules.

The following are important parts or bundles in the Liferay 7 / DXP module development.

API

API contains all interfaces java classes. It is separated from implementation bundle.

Service

Contains the service (business logic) and persistence implementations.

Web

Web contains the presentation layer files such as HTML, JSP, CSS and JavaScript files.

Test

Contains the tests. These are not included in the app for production.

Liferay Modular Architecture

Picture source form Liferay.com

Liferay 7/DXP have several layers in the architecture like Liferay Core, Foundation, and Web experience, Collaboration, Forms & Workflows and Independent Apps.

Liferay Core

Liferay Core consist of all core APIs and Liferay Kernel. Its basic components which will used by all other modules or layers in the Liferay portal.

Foundation

This layer consist of Liferay building blocks implementation such as Users, Roles, Groups, Themes and Permission System.

Applications Layer

Liferay application layer separated with different group of modules and these all are independent apps separated from Liferay Core and Foundation. It uses the both Liferay Core and Foundation layer APIs and Its independent modules.

Liferay core and Foundation layers are packaged as WAR file deployed in the traditional application layer. Usually all these APIs and Implementations available in ROOT directory that deployed in Application server deployment directory.

Liferay independent Apps are made it as OSGi bundles, deployed in the OSGi container. All liferay bundles are found in OSGi directory of Liferay portal.

Liferay have provides the gateway which communicate with Liferay Core and Foundation layer to fulfill liferay application features.

Liferay 7 /DXP still support the plugins development and its deployment. This is a reason still we can see traditional application server. Liferay older versions migration to Liferay 7 / DXP possible through to keep traditional application server in the Liferay 7/DXP.

To customize or develop new features in Liferay 7/DXP, Developer follows the OSGi modularity specification to develop Liferay 7 / DXP apps.

Now all liferay applications possible through the OSGi bundles. Still some of the limitations for Liferay Themes, so we follows the Web based development for themes. Portlets, hooks can make it as OSGi bundles and themes can make it as WARs. Liferay 7 / DXP still support Plugins SDK so that we can develop liferay applications as plugin wars.

Liferay 7 / DXP suggested using OSGi Declarative Services (DS) framework to develop Liferay 7 application bundles. We can use Apache Blueprint framework as well.

Liferay have used Apache Gogo shell Command Line Interface to manage bundles, its means Activate/Deactivate Start/Stop bundles in the OSGi container. Bundles lifecycle controlled via Apache Gogo shell.

Interesting point is, we can disable/ enable Liferay features through Apache Gogo shell and we do not need to un-deploy or remove bundle from OSGi container. Just we can deactivate or activate is enough.

Liferay have provided good tools to develop Liferay 7/DXP modules. Follow the below articles to know more about Liferay 7/DXP Module Development. Follow below link to find more details about Liferay Application Development Tools

http://www.liferaysavvy.com/2017/10/liferay-7dxp-development-options.html

Author

Meera Prince

Liferay Contributor of the Year 2016
Liferay Top Contributor Award Winner 2015

Liferay Contributor of the Year 2014

Liferay Top Contributor Award Winner 2013

http://www.liferaysavvy.com 

Read More