Liferay Beginner's Guide: Quick and easy techniques to build, deploy, and maintain your own Liferay portal with this book and ebook

Liferay Portal adopts an architecture that is flexible. It divides a webpage into a theme, a layout template, and portlets. The look-and-feel of Liferay Portal can be completely customized.

In our context, a portal is a web portal. A web portal refers to a website that provides a broad array of resources and services, which typically include e-mail, forum, searching, and online shopping. Yahoo! was one of the first portals.

There are also web portals for enterprise use. These portals are called enterprise portals. An enterprise portal provides content and collaboration for the employees of an enterprise. It is set up as an intranet application. Liferay Portal is often customized into an enterprise portal.

Most content at a Liferay Portal site comes from its portlets. A Liferay Portal contains portlets, as a window contains panes. A portlet is different from a pane, in that it consists of text and images.

A portlet works like a servlet. A portal URL request to the application server will invoke one or more portlets. The portlets run and produce HTML markup. Liferay Portal assembles the HTML markup into an HTML file. It returns the HTML file to the requesting browser.

Liferay Portal was named a leader in the Magic Quadrant for Horizontal Portals report of Gartner in 2010 (http://www.gartner.com/technology/media-products/reprints/liferay/206214.html). What is a horizontal portal? A horizontal portal covers many areas. It can be used as a platform for multiple social and collaborative purposes. It can also be used by more than one company in the same industry. Liferay Portal is a horizontal portal, because it has a collaborative suite of blogs, wiki, mail, and calendar portlets. Its message board and chat portlets can be used for social activities.

A vertical portal focuses on one functional area. It is a specialized entry point to a specific market, industry, or subject area.

The Yahoo site is a horizontal portal. It is a platform for multiple social and collaborative purposes. The YouTube site is a specialized entry point for video fans: it is a vertical portal.

A user uses an open source portal product, free of charge. He/she can modify and extend its source code. Liferay Portal is an open source portal. It is distributed under the GNU, Lesser General Public License (LGPL) (http://www.gnu.org/copyleft/lesser.html).

Liferay Portal is available in two versions: Community Edition (CE) and Enterprise Edition (EE). A client can use its community edition, free of charge. If a client wants support from Liferay, Inc., they can buy the Enterprise Edition.

You can study the source code of an open source portal to learn portal technologies (Refer to https://github.com/liferay for the source code of Liferay Portal). A commercial portal product is more expensive than the enterprise version of an open source portal. IBM WebSphere portal and Microsoft SharePoint portal are commercial portal products.

This book is based on Liferay Portal Version 6.0. We will use this CE version to illustrate the features of Liferay Portal and set up a sample website.

Every release of Liferay Portal comes with the source code. You can compile and build the portal from the source code, if you choose to do so. You can study the source code to learn how Spring and Hibernate are used. You can modify the source code and re-build the portal if you like.

These are only some of the advantages of using an open source portal product.

Which of the following statements are true about Liferay Portal?

a. Liferay Portal is a Java web application

b. Liferay Portal was first developed for a non-profit organization

c. Liferay Portal is an open source portal product

d. All of the above

Liferay Portal adopts a Service Oriented Architecture (SOA). Its architectural diagram is as follows:

In this diagram, Liferay Portal handles Hypertext Transfer Protocol (HTTP) requests from a user. The request will first be received by the Struts servlet. This servlet runs and renders portlets. During the process, the code invokes singletons, configured with Spring Application Programming Interface (API) and plain Java objects. It uses the Hibernate API to get data from or enter data into the database. Optionally, it may use the Java Messaging Service (JMS) to send out messages.

On the other hand, Liferay Portal also provides web services for programs running on other servers. The portal uses Apache Axis specification to generate web services. The Axis configuration is specified in the server-config.wsdd file under the portal/tunnel-web/docroot/WEB-INF/ folder. These are a list of Simple Object Access Protocol (SOAP) services. When an external program asks for a web service from the Liferay Portal, the Axis servlet in Liferay Portal will answer it. It will also call singletons initialized through Spring framework and call the plain Java objects. These plain Java objects will use Hibernate API to access the database.

The architecture of Liferay Portal allows it to run on all major application servers and servlet containers, databases, and operating systems. It can be deployed on over 700 infrastructure combinations. For example, you can use MySQL or Oracle; you can run Liferay Portal in Tomcat or WebSphere.

You can plug in Solr for searching and Kaleo for workflow to Liferay Portal.

The portal administrator can apply different themes on different Liferay Portal pages. He can change the layout template of every portal page. By drag-and-drop, he can add portlets onto a portal page.

Liferay Portal is compliant with Java and portlet standards. The following standards have been used in the development of Liferay Portal:

Choose the correct statements:

a. Liferay Portal is a web service producer out-of-the-box

b. Liferay Portal adheres to Portlet 2.0 Specification

c. The development of Liferay Portal started in 2000

d. All of the above

Liferay Portal themes take care of most of the look-and-feel of a Liferay Portal application. A theme usually contains a company logo, a navigation bar, footer, Cascading Style Sheet (CSS) code, and JavaScript code. A Liferay Portal site can have multiple themes. In this way, a user with proper permissions can dynamically apply a different theme to each portal page, if he/she chooses to do so.

Liferay Portal divides a page area into smaller sections with a layout template. Liferay Portal comes with 10 layout templates. A portal administrator will drag-and-drop one or more portlets into one such smaller section.

The theme and layout template makes a Liferay Portal site flexible. It is easy to change the look-and-feel of a Liferay site with the theme and layout template.

Liferay Portal provides communities and organizations for administering users and the sites. A user can belong to communities and/or organizations.

A community is a collection of users with similar characteristics and interests. The portal administrator can create a sub-site with each community.

An organization is a hierarchical collection of users. A user can be a member of multiple organizations.

Either a community or an organization can have public and private web pages. Any user at the Liferay Portal site can access the public pages, while only a member of a community or organization can browse the private pages of his/her community and/or organization.

Liferay Portal has rich content management features.

The content displayed at a Liferay Portal site can be dynamic or static. The dynamic content can be updated by multiple users at any time. It usually comes from data saved in database tables and is presented with custom portlets. The static content is the files uploaded through the Document library portlet and web content created with the web content portlet.

The following portlets are part of the Content Management System (CMS) of Liferay Portal:

The following portlets take care of Web Content Management (WCM) in Liferay Portal:

The asset publisher portlet displays documents, images, blogs, wikis, message board entries, bookmarks, and web content.

The static content at the Liferay, Inc. site is created with the web content portlet (or web content display portlet). It is displayed with the web content display portlet.

The Liferay forum site at http://www.liferay.com/community/forums is made of the messages board portlet, while the Liferay blogs site at http://www.liferay.com/community/blogs is set up with the blogs aggregator portlet and the blogs portlet.

Which of the following statements are true?

a. In a typical Liferay Portal page, a theme wraps a layout template, which in turn wraps portlets

b. Liferay Portal has powerful web content management features

c. Liferay Portal is pre-installed with more than 60 portlets

d. All of the above

To install Liferay Portal, you need more than 300 MB of disk space and at least 1 GB of Random Access Memory (RAM). The application server or servlet container that houses Liferay Portal runs at a port. You should make sure that other applications on your computer are not using that port.

Liferay Portal is written in Java. It runs on any computer where you can install the Java Runtime Environment (JRE) and an application server or a servlet container. It runs on computers that support either 32-bit JVM or 64-bit JVM.

Some features of Liferay Portal also need a mail server for support.

This machine has 4.00 gigabytes of RAM installed, of which 3.24 gigabytes are available. Because the available memory is larger than is required for running a Liferay Portal instance, we can install a Liferay Portal instance on this laptop computer.

Liferay Portal can be combined with multiple kinds of database servers and application servers.

As a web application, the running environment of Liferay Portal involves a browser, Java Virtual Machine (JVM), a database server, and a mail server.

The previous screenshot confirms that the JDK has been successfully installed!

You can download an application server or servlet container from its website and install the Liferay Portal Web Application Archive (WAR) file and dependency Java Archive (JAR) files in it. Alternatively, if Liferay has already bundled Liferay Portal with an application server or servlet container, you can download that bundle, unzip it, and install it.

Liferay Portal supports the following application servers:

Liferay Portal also runs in the following servlet containers:

For every release, Liferay, Inc. installs Liferay Portal in some open source servlet containers and application servers. The resulting packages are called Liferay Portal bundles, which are ZIP files. A user can download one such bundle, unzip it, and install it. The presently-available bundles are as follows:

We can connect Liferay Portal to the following database servers:

In this book, and at the sample site, we will run Liferay Portal with MySQL database. MySQL is the world's most popular open source database. The current version of Liferay Portal requires MySQL version 5.0 or above.

The previous screenshot confirms that the MySQL database server has been installed successfully.

You can use Firefox (3.0 and above), Internet Explorer (IE) (7.0 and above), Chrome, Safari, and Opera to browse a Liferay Portal site.

The ability of a web browser to access a website depends on the user interface (UI) technologies used in the development of that website. Because Liferay Portal is highly customizable, you may be able to interact with a customized Liferay Portal site with more varieties of browsers on the market.

A Liferay Portal theme decides most of the look-and-feel of a Liferay Portal site. In almost all situations, a client will develop a custom theme for their site. The user interface technologies that they use for their custom theme decide the accessibility of their site.

Liferay 6.0 CE uses Alloy user interface (Alloy UI). Alloy UI has combined the following technologies:

HTML 5 defines the HTML elements in a webpage. It is used for the structure of a portal page. CSS3 is used to add styles to document object models (DOM). YUI3, which includes JavaScript API, is used to make the HTML elements dynamic.

HTML 5 is the latest revision of the HTML standard. HTML 5 is still a work in progress. However, Safari, Chrome, Firefox, and Opera already support some of its features in their latest versions. IE 9 will also be available to support some HTML 5 features.

Liferay Portal has a feature to support browsing in iPad and smart phones in its 6.1 CE version. This is achieved by detecting the screen layout of the device with JavaScript code. When the computer screen layout is 960px wide, Liferay Portal knows that it is a desktop computer or iPad in landscape mode; when the screen layout is 320px wide, Liferay Portal knows it is a smart phone in portrait mode. Liferay Portal will apply a corresponding Cascading Style Sheet (CSS) class, and thus adjust the dimensions of an image and other content on the portal page.

Liferay Portal has a feature to convert web content, wiki articles, and message board content into PDF files and files of other formats. This feature relies on the integration of the OpenOffice application. OpenOffice is an open source office software that consists of a word processor, a spreadsheet program, a drawing tool, and a math program.

Congratulations! You have successfully installed OpenOffice on your computer!

Liferay Portal depends on a service provided by OpenOffice to convert files.

The previous command means that OpenOffice has started a service with the headless option. Now, this service will accept a request at port 8100. It is waiting for the request from a server, whose Internet Protocol (IP) address is 127.0.0.1, which means the local host.

We can check to see how the OpenOffice service is running.

As you can see, a service is listening at port 8100 for a request from 127.0.0.1.

If you reboot your computer, this service will be stopped and gone, because you started it manually. So, a better choice is to set up this service as a Windows service, which will be started whenever your machine is rebooted.

You may install Liferay Portal in a bundle, such as liferay-portal-tomcat-${version}.zip , on your computer. If it is a Linux machine, you can run the unzip liferay-portal-tomcat-${version}.zip command to extract the files. On a Windows machine, an unzip tool may be already available, or you can download WinRAR at http://download.cnet.com/WinRAR-32-bit/3000-2250_4-10007677.html and install it to explode the ZIP file.

Which of the following statements about the installation environment for Liferay Portal are true?

a. Liferay Portal can be installed on a laptop computer

b. Liferay Portal comes with a hypersonic in-memory database

c. Liferay Portal depends on Java Virtual Machine

d. All of the above