Quản lý cấu hình web - part 4 docx

[ 14 ]Web scripts Web scripts provide RESTful access to content held within your Alfresco Enterprise Content Repository.. There are three aspects of workflows in Alfresco: • Workflow def

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• One temporary workflow sandbox per active workflow instance per

web project:

Virtualization and In-context Preview

Virtualization and In-context Preview is core to the sandboxing concept Virtualization means that each user has a complete view of all current, approved, checked in content along with those unique modifications made within the context of their sandbox Alfresco provides a complete virtual view of the website as it would look if all changes

in a sandbox were committed to the live site even when previewing any non-modified

or modified asset in a sandbox This is In-context Preview

Each user in the context of their sandbox can do rigorous and thorough quality checks for all changes they are posting to the website

Transparent layers

Transparent layers are the means to implement sandboxes in Alfresco This layer is

a central construct in the Advanced Versioning Manager (AVM) repository, very

similar to the UnionFS Linux filesystem, and is used to define "composite" stores that can "read through" content from other stores It can be defined at the store, directory,

or file level

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From Alfresco 3.1 onwards, transparent layers can be configured by a Content Manager in the Staging Sandbox of a web project This is useful for:

• Defining web project templates

• Reusing content across multiple web projects

• Explicitly segregating different groups of content producers for separate web projects

Web forms

Web forms are used in Alfresco WCM to capture content from the user, and store

as XML An XML schema needs to be created by form developers for capturing content It is then rendered automatically as a user-friendly web-based form for content contributors

Alfresco uses the open source project Chiba, an XForms implementation used to

transform the XML schema into an internal representation of a form (XForms), and then present UI controls for elements and attributes described in the schema This helps to render the form entry UI to the end users

Web forms are created and administered in the Web Forms space within the Data Dictionary As they are located in Alfresco Spaces, they are accessible by the default

CIFS, FTP, and WebDav interfaces They can also be configured with rendering engine templates for generating renditions of the collected content

Rendition templates

The web form-managed XML can be transformed with rendition templates and the corresponding content into rendered output Server-side templating languages, such as FreeMarker, XSLT, and XSLT-FO are provided by Alfresco After a content item (XML file) is created via a web form, each rendition template configured for that content type is executed, producing an output file per template (shown in the following diagram) Typical formats for renditions of web content include HTML, JSP, PDF, XML, and so on:

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Web scripts

Web scripts provide RESTful access to content held within your Alfresco Enterprise Content Repository You can therefore place controls on your enterprise content to manage it, and provide uniform access for a wide variety of client applications and services, such as browser, portal, search engine, or any custom application

Web scripts allow you to:

• Easily access, manage, and cross-link your content via a customized RESTful API You do not need any compilation, generators, server restarts, complex installs, tooling, or Java knowledge All you need is your favorite text editor

or the Alfresco Explorer web client

• Build custom URI-identified and HTTP-accessible Content Management Web Services

• Turn your Alfresco repository into a content management-powered

HTTP server

Workflows

Alfresco WCM uses JBoss jBPM for all workflows There are three aspects of

workflows in Alfresco:

• Workflow definition: The creation and deployment of the jBPM workflow

into Alfresco repository

• Workflow association: The assignment of a workflow to a web project, which

specify the actors (reviewers identified)

• Workflow instance: Created when content that is specific to the associated

change set is submitted Additionally, Alfresco comes with Web Site

Submission workflow out of the box, which allows for serial and parallel approval of content

Content delivery concepts

In Alfresco there are three delivery models: static, dynamic, and a hybrid of both static and dynamic In a static delivery model, all requests to the web server return a static file of XHTML, XML, JSON, and so on to the web client without any additional processing (no CGIs, no SSI, and so on)

In a dynamic delivery model, all requests to the web server return objects of type XHTML, XML, JSON, and so on that are processed by some application server to render the resulting document

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Static delivery model

In such a model, pages are rendered as part of the content production process The resulting HTML and associated assets (images, CSS, JS, and so on) are then published

to the filesystem, typically a document root of a web server This provides high levels of scalability on simplified production architectures (web server farms) This model, however, has limited personalization and there is a set number of rendering technologies (FreeMarker, XSLT, and XSLT-FO)

A File System Receiver (FSR) will need to be installed and configured to receive

published static content from the Alfresco server The FSR consists of a small server that receives updates from an Alfresco repository and publishes them to a flat

filesystem, which is then typically served up by a web or application server The following diagram illustrates this process:

Dynamic delivery model

A pure dynamic model publishes content to an Alfresco Runtime, thereby making the content available for dynamic queries with basically any web technology (PHP, Python, J2EE, AJAX, Flash, Cold Fusion, and so on) This provides ultimate flexibility

in what and how content is displayed on a page This provides the highest levels

of personalization, but will require significantly more resources on the delivery servers for similar levels of traffic For all but the smallest websites, significant effort

is required in architecting, developing, and testing to ensure website or application stability This is particularly the case during unexpected high-volume situations (for example, a Government website during a national disaster) The following diagram illustrates the dynamic delivery model:

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An Alfresco System Receiver (ASR) will need to be installed on a server to facilitate

the dynamic delivery model The ASR is just another instance of the Alfresco server The ASR allows a web project being authored in one Alfresco server instance to be deployed to another separate instance of Alfresco

Overview of delivery models

The following is a summary of static and dynamic delivery models:

Static "Bake" Model Dynamic "Fry" Model

Application developer skill sets FreeMarker, XSLT,

The best of both worlds

A hybrid approach is the preferred approach regardless of the WCMS and the underlying technologies Determination of what is static and what is dynamic is highly dependent on the type of website and web applications

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Users also have the option of a hybrid delivery approach This approach can be executed as follows:

• The web architecture model should be designed to support the dynamic model This includes the ability to deploy content to both filesystems and Alfresco runtimes for flexibility

• Leverage the static model wherever possible If content must be personalized

to a single user or a very small set of users with few "page" impressions, it most likely needs to be dynamic Otherwise, it can be static

• Choose a page composition model appropriate to the overall site and each page on the site:

° Outside-in: Each page is static HTML with static components already

embedded, but dynamic components or applications such as AJAX and Flash can be included

° Inside-out: Each page is dynamic and includes all page components

dynamically regardless of whether those components are static

or dynamic

Significant enhancements in Alfresco

WCM with Version 3.3

A bunch of new features focused on helping companies manage their web presence have been introduced in Version 3.3 A list of these is as follows:

• Alfresco Web Editor: In-context editing to Alfresco (non-AVM) stored

content has been introduced This will allow content authors to edit content items stored within an Alfresco repository directly from the web page Alfresco 3.3 also provides the Web Editor Framework, a JavaScript client-side framework, rendering a toolbar, and associated controls

• Transfer Service API: Developers can build solutions that transfer content

between Alfresco repositories (non-AVM) using the Transfer Service API This is useful to WCM architectures where Alfresco provides both authoring and delivery tier components and allows rich-content structures and

relationships to be maintained between Alfresco environments

• Rendition API: The Rendition API will allow developers to build solutions

for easily repurposing content for the Web FreeMarker and XSLT templates can also be used as part of the Rendition API

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• WCM deployment: The Alfresco Deployment Receiver is configured as

sub-system and a new Data Dictionary folder called Web Deployed

is configured to default as the deployment target AVM to DM-WCM

deployment facilities have been enhanced to add an additional deployment target This additional deployment receiver allows WCM content that is authored and stored within the AVM to be deployed to local and remote Alfresco repositories (Alfresco DM)

Alfresco Web Editor

The Alfresco Web Editor (AWE) is a Spring Surf-based web application that utilizes

the Forms Service to provide in-context editing capabilities to Alfresco repository

content (non-AVM) Alfresco 3.3 also introduces the Web Editor Framework (WEF),

which is a client-side JavaScript framework that is a dependency of the AWE

With the initial release, the AWE will support JavaServer Pages (JSP)-based websites

by providing a tag library Additional languages will be supported in future releases with FreeMarker and PHP being on top of the list The tags have been designed for easy implementation so that a developer can enable the AWE with minimal effort, and without effecting the CSS layout and design of the site

The simplest and quickest way to deploy AWE is to use the prebuilt WAR (awe.war) file and deploy it in the same application server instance of your web application Being a Spring Surf-based application, AWE does not have to be deployed in the same application server instance as the Alfresco repository However, this section presumes that it is

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An easily navigated site, with information consistently organized in a logical

fashion, is what most organizations want to provide But delivering consistent

organization with proper adherence to corporate branding and design standards can be difficult when several authors are contributing content If more than one designer or Webmaster posts content, standards can easily become compromised and consistency diminished

In this chapter, we have learned that Alfresco gives you a web content management solution that:

• Has content component architecture where content is separated from format;

it is easier to reuse

• Uses an open, object-based API—an open interface providing compatibility with new or emerging technologies

• Is an open source alternative

The next chapter focuses on installing Alfresco and various components around it Installation on various operating environments is detailed therein Also explained

is the installation of various components like OpenOffice, ImageMagick, Microsoft Office Add-ins, Flash Player, and SWFTools

Installation and Configuration

This chapter is aimed at enabling you to understand and carry out various aspects

of the Alfresco WCM installation and configuring various components around it

A basic understanding of Alfresco architecture, various installation options, and the key terminologies used are all a part of this chapter The Alfresco development environment needs to be set in place before we can work with the tools

The installation procedures can also vary depending on the kind of system you have

in place to set up and configure Alfresco First, we will go through the installation procedures for a Microsoft Windows-based system Linux-based systems also follow similar steps We will go into detail later in the chapter

At the end of this chapter, you will have learned the following:

• Components to install

• Configuring the Alfresco Setup

• Setting up the Alfresco WCM development environment

Following is the list of softwares you need on your machine before you

install Alfresco:

Component Recommendation

Java SE Development Kit (JDK) JDK 6 is required

database If you intend to use a different database, install and configure the database before you install Alfresco