Content storage format - Alfresco provides a nice feature called "web-forms". There are two types of forms currently available i.e. WCM forms and ECM forms. Both of them capture the input data and store it as XML. You can also choose to apply content transformation using XSL. It helps to save final output as either HTML, Text or PDF etc. Not to forget, the content is actually captured and saved as XML. In my perception one of the strengths of Alfresco is its content repository. If XML is target format, it is saved in CR as a cm:content property and it defeats the whole purpose. If CR is not aware of the structure of the content, it defeats the purpose of content model definition? It is not very different from storing the content xml as plain string in database. Frankly I don't see any benefit of using CR over database in this method.

To avoid such inefficient use of alfresco, you can take some effort and write a custom form component. Use custom forms (develop forms in your application and then communicate with alfresco using API) to capture user data and store them in content repository in defined content model and schema.

This will help you in -

• Content repository now understands the structure of your content. This is really important and if you have any doubts, please post that in comments. I might write about it later in my blog.
• You can apply your custom content transformation logic so that content can be exported in XML / HTML / custom output format. Just generate this once every time you update the content. It improves the efficiency of content management system to deliver target content.
• You will have a flexibility of own input format, use JSP or rails forms, its your choice!

Deployment benefits - Alfresco has another great strength, Deployment Infrastructure. I think its also one of its weaknesses. Use it wisely to improve your release management. On the release date of web application usually you come across content sanity issues, or format differences. To avoid that, setup proper environments where alfresco can sync content and test it before you push it to live. This might save you a lot of frustration.

Although its a great feature, there is a caveat to that. Generally all the code for web application is stored in CVS systems. Alfresco code (web scripts, web form definitions etc.) is stored in alfresco. Keeping the versions of alfresco code and web application code is nightmare. Develop some automated web script deployment tool and every time you release, wipe out all the previous webscripts and deploy new ones from the CVS. This always makes you keep updated code in the CVS and versioning becomes much robust.

First get the distribution of VPNClient for linux. This distribution is valid for 32-bit as well 64-bit installations.

wget http://tuxx-home.at/vpn/Linux/vpnclient-linux-x86_64-4.8.01.0640-k9.tar.gz

tar -xvzf  vpnclient-linux-x86_64-4.8.01.0640-k9.tar.gz

cd vpnclient

sudo ./vpn_install

This command should result in similar output below:

Cisco Systems VPN Client Version 4.8.01 (0640) Linux Installer
Copyright (C) 1998-2006 Cisco Systems, Inc. All Rights Reserved.

By installing this product you agree that you have read the
license.txt file (The VPN Client license) and will comply with
its terms.

Directory where binaries will be installed [/usr/local/bin]

Automatically start the VPN service at boot time [yes]

In order to build the VPN kernel module, you must have the
kernel headers for the version of the kernel you are running.

Directory containing linux kernel source code [/lib/modules/2.6.27-7-generic/build]

* Binaries will be installed in "/usr/local/bin".
* Modules will be installed in "/lib/modules/2.6.27-7-generic/CiscoVPN".
* The VPN service will be started AUTOMATICALLY at boot time.
* Kernel source from "/lib/modules/2.6.27-7-generic/build" will be used to build
the module.

Is the above correct [y]

Making module
make -C /lib/modules/2.6.27-7-generic/build SUBDIRS=/home/sachin/vpnsandbox/vpnclient
modules
make[1]: Entering directory `/usr/src/linux-headers-2.6.27-7-generic'
CC [M]  /home/sachin/vpnclient/linuxcniapi.o
In file included from /home/sachin/vpnclient/Cniapi.h:15,
from /home/sachin/vpnclient/linuxcniapi.c:31:
/home/sachin/vpnclient/GenDefs.h:113: error: conflicting types for ‘uintptr_t’
include/linux/types.h:40: error: previous declaration of ‘uintptr_t’ was here
make[2]: *** [/home/sachin/vpnclient/linuxcniapi.o] Error 1
make[1]: *** [_module_/home/sachin/vpnclient] Error 2
make[1]: Leaving directory `/usr/src/linux-headers-2.6.27-7-generic'
make: *** [default] Error 2
Failed to make module "cisco_ipsec.ko".

To get around this error you need to patch couple of files in the existing source. Download the patch and apply it.

wget http://projects.tuxx-home.at/ciscovpn/patches/vpnclient-linux-2.6.24-final.diff

patch < ./vpnclient-linux-2.6.24-final.diff

After successful patch of the files you can proceed to the install procedure again -

sudo ./vpn_install

You should be able to see all files getting compiled successfully. If it is successful you will see a message like below -

* You must run "/etc/init.d/vpnclient_init start" before using the client.
* This script will be run AUTOMATICALLY every time you reboot your computer.

Now you can copy your vpn configuration files (*.pcf) in /etc/opt/cisco-vpnclient/Profiles folder and you can start connecting the the vpn network using command -

vpnclient connect <profile_name>

If you want to use certificate based authentication for the connection then following additional steps will be required.

sudo cisco_cert_mgr -U -op import

This will ask you for the certificate file location and password for the file if required. Enter the passwords for importing certificates if required and proceed with connection.

DVD Regions Map

I own few more DVDs belonging to 2/3/4 regions. I own another DVD player (my PlayStation 3) and that is also region locked. Now I have two very expensive machines and lots of original DVD titles yet can't play any of them. I don't know who created this *stupid* protection system which prohibits user from playing legal copies!

I tried various things on my Mac -

• Using VLC media player for OS X
• Using utilities like MacTheRipper for decrypting the dvd
• RegionX for changing the region indefinite times

None of the above works. I have almost read thousand blog / forum posts related to DVD region issues with Mac but everything was completely failure. Apparently MacBooks have this "MATSHITA DVD-R   UJ-867" super drive which has no way of getting around the protection. I don't want to replace the firmware to region free as it will void my company laptop warranty which makes me crazy.

Now what reward I got by paying for the legal versions of the DVDs? In India any English movie DVD will cost you around Rs. 399-699 which is considerably expensive. You pay Rs. 800-1000 for 1 month of the internet connection. Why I will not be tempted to download nicely ripped DivX movie from torrent instead of buying freaking expensive DVDs which don't play at all?

Now can I demand my money back for these movies? Can I illegaly download the DivX rip of the movie and play it on my laptop and still it will be legal? I really don't know but I will never buy legal DVDs for sure!

  

Complex Workflow Designs

As I mentioned in my earlier post that I will be writing few more posts about the Alfresco. This is second installment in the series. If you are thinking to use Alfresco at the center of your application then it is hard that it will not have a workflow. If your business process is just more than simple workflows mentioned in Alfresco, then for sure you have to write your own business model definition.

If you are planning to do so, here are few lessons I have learned –

• Simplicity – We got lot of benefits just by keeping our process definition simple and neat. Don’t add unnecessary steps which will cause confusing steps for the end users.
• Right things at right place – Alfresco is very flexible in terms of business logic implementation. You will always have multiple options to accomplish same operation. Web Scripts, Java classes or Web Service and you will be tempted to use different things at times. Decide one approach and stick to it. Put as much as logic in the workflow and don’t spread across the workflow business logic outside the workflow.
• Loops can be evil – Loops in the workflow actions can be daunting at times. Rethink on the circular steps in the workflow and make sure you are not violating the “simplicity” rule. It might be difficult sometimes to achieve these steps.
• Blocking is good sometimes – Next bigger decision should be synchronous operations or asynchronous. All the operations which might result in inconsistent states should be synchronous i.e. transactional. Asynchronous operations are better in terms of responsiveness. Sending e-mails could be asynchronous tasks as you people can receive emails after couple of seconds, but if it is related to pushing records to a queue, let it be synchronous. You got the idea!

You are advised to check Alfresco wiki for more details. There is plenty of documentation available for the administration and authoring custom workflows.

Few tips for better content models -

• Use aspects for specializing types instead of defining content types. There are few advantages of that, aspects can be applied or removed at run-time which gives you much more control over the dynamic nature of types.
• Aspects also helps in keeping the default set of properties over a content type to be small. Alfresco recommends you to prefer aspects over custom content types.
• Aspects helps you to logically group properties. This helps your data to be part of multiple groups at the same time. If you have aspects Publishable and Indexable; you can apply or revoke a nature at your will without much hassle.
• Indexing is very helpful for searchable content. It is useful but use it wisely. The cost of indexing in Alfresco is much higher than cost of index in Databases as this will be full-text search indexes. It will take up more disk space as well as time to index the data. Don't index the content which people are not expect to search! You can define this at the time of content model definition.
• Versioning is similar to indexing and use this wisely. The content which is versionable is handled separately by Alfresco. This might be affecting performance as your repository size grows. Don't mark content as versionable if you don't plan to maintain revisions for content.

I will continue this series with other experiences with Alfresco. Later.

• Easy to extend
• Can handle any workflows
• Provides easy ways to retrieve tasks, definitions, paths etc.
• Provides as much functionality possible which is available in Alfresco Workflow Console.

Alfresco workflow console is command line interaction component which allows you to manipulate, get information about workflows using simple commands and I wanted to do all that using JavaScript. I started exploring the source code and found a class 'org.alfresco.service.cmr.workflow.WorkflowService'. This class has generic API which allows you to do all the operations possible through workflow console. This bean is used for workflow console operations. So all I needed was expose this bean in JavaScript as root object and start using it. That simple! I wrote a simple java class to expose the bean as follows:

package com.xxxx.yyyy.workflow;
 
import java.util.List;
 
import org.alfresco.repo.processor.BaseProcessorExtension;
import org.alfresco.service.ServiceRegistry;
import org.alfresco.service.cmr.repository.NodeRef;
import org.alfresco.service.cmr.workflow.WorkflowService;
 
public class WorkflowManager extends BaseProcessorExtension {
	private ServiceRegistry services;
 
	public void setServiceRegistry(ServiceRegistry serviceRegistry) {
		this.services = serviceRegistry;
	}
 
	public WorkflowService getWorkflowService(){
		return services.getWorkflowService();
	}
}

The method getWorkflowService() exposes the workflow service to the JavaScript calls. To expose the Workflow Manager as root object in JavaScript create WEB-INF/classes/alfresco/extension/custom-script-context.xml and you will be good! (If you don't know how to do that, read this) Now, you can get the handle of workflow service in JavaScript code. Yet, we need to write a small component which will allow us to retrieve the active workflows, tasks etc. To do so, I wrote a small JavaScript object which provides those functionality to the user.

var workflowService = workflow.getWorkflowService();
 
var W = {
	transitions: function(noderef){
		var task = W._currentTask(noderef);
		var trans = [];
		try{
		var tasks = task && task.path.node.transitions;
		for(var index=0; index < tasks.length; index++){
			trans[trans.length] = tasks[index].id;
		}
		}catch(error){
			// Ignore error
		}
		return trans;
	},
 
	move: function(noderef, command){
		workflowService.endTask(W._currentTask(noderef).id
                , command);
	},
 
	_workflowPath: function(noderef){
		var workFlows = workflow.getWorkflows
                      ("workspace://SpacesStore/" + noderef, true);
		if(workFlows.size()>0){
			return workFlows.get(0).id + "-@";
		}
		return "";
	},
 
	_currentTask: function(noderef){
		var curTask;
		var tasks;
		try{
		tasks = workflowService.getTasksForWorkflowPath
                           (W._workflowPath(noderef));
		if(tasks.size() > 0)
		      curTask = tasks.get(0);
		} catch(Error){
			// Ignore error
		}
		return curTask;
	}
}
 
function initWorkflow(noderef)
{
	var wflow = actions.create("start-workflow");
	wflow.parameters.workflowName
             = "jbpm$xxxxyyyy:abc"; // your workflow name
	wflow.parameters["bpm:assignee"]
             = person.properties.userName;
	wflow.parameters["bpm:workflowDescription"]
             = "Put your description";
	wflow.execute(noderef_for_which_workflow_will_associate);
}

Thats it! The initiate workflow method is used to apply a workflow to a node. Once that is done, the W object can be used to do operations like retrieving the active tasks, ending the workflow and making the workflow transition. Hope that helps. If you need more workflow related information and reading material you can visit following places:

• JBPM jPDL Documentation (here)
• Alfresco workflow wiki (here)
• ECMArchitect Advance Workflow Guide (here)

Beta software prohibited! (Photo obtained from here)

I was really disappointed over past few weeks about Ubuntu 8.04 release. The major reason of disappointment was Firefox 3 beta 4-5. The browser might be having lot of new things which are amazing, the performance might have been improved for JavaScript execution but in reality, the overall performance of the browser wasn't that good. I was experiencing slow browsing speeds, sometimes the browser wouldn't respond and sometimes even crash.

Firefox 3 is still gaining popularity and there are tons of plug-ins which are still not compatible with it. My favorite plugins are no longer usable with Firefox 3 and that was a big drag for me. Firebug was one of them.  The main reason why I feel very disappointed was Firefox 3 was in beta!

Ubuntu was simplifying Linux for all the users who don't want to touch command line for writing documents and browsing internet etc. They are doing a great job on that front too. Firefox 3 made me think is it going away from that objective by giving beta software distribution? I will urge Ubuntu community for not including any of the beta software in mainstream distribution for any reason. That might not only discourage non-technical users but also put wrong message on the table.

For those users who have similar problem, they can uninstall the Firefox 3 from synaptic package manager and install Firefox 2 browser instead. Happy browsing!

The && operator in JavaScript can be acted in two ways. The normal 'and' operator which is used in determining the conditional logic results. The other lesser known feature of JavaScript is the guard operator. In following code -

 
/* The if is checking if specs is not undefined, false, null,
"" (empty string) or 0 (numeric zero) as these all values
are falsy conditions in JavaScript */
 
if(specs)
     width = specs.width;
 
// To avoid the if condition you can simply do like -
 
width = specs && specs.width;
 
/* This makes sure that specs is not falsy and they
returns the second operand which is convenient
way to write null check */
 

The same is with || operator too. If the first operand is falsy then it just returns the second operand instead. Consider following code:

 
name = specs.name || "Name not set";
/* Use the specs.name, but if name doesn't have a value, use default
value instead. */
 

Very simple and very efficient!

I am working on a project which involves some bit of alfresco customization to meet the customer needs. This involves configuring alfresco for Windows SSO, allowing users to map their home space in alfresco as network share, knitting a workflow tightly integrated with their business process and writing some dynamic content generation code for reporting, user interaction and for auditing purpose. We could do most of the things straight away and we are quite happy with kind of response alfresco was giving. Everything is clean and configurable. Basically alfresco is built using spring framework; so you can configure custom beans or extend existing beans very easily via some xml files. There are tons of different services and pre-configured beans which might be little overwhelming for the beginners but, as you started to get familiar it doesn't feel so bad.

We were at a point where we wanted to write some server side logic to create a dynamic (web 2.0) UI which has lot of interaction based on data queries with content repository. So we needed easy approach to query repository, minimal xml configuration, ability to change / update logic easily, faster development cycle to start with. Alfresco provides lot of options to communicate to repository -

• Java API (most raw access to the repository, repository instance is singleton so that will be injected as dependency via spring configuration)
• Web Service - Very standard SOAP and XML RPC based communication
• RMI - Java RMI which is another standard method looks similar to Web Services
• RESTful JavaScript API

I was excited by last option the most. I thought, lets explore the last one as first three were mundane and I knew what are the pros-cons of most of them. Alfresco provides a clean MVC around content repository and other parts of Alfresco (viz. workflow, user homes and some root objects) where controller is a pre-configured servlet, model is JavaScript code and view is a freemarker template. The beauty of the system is lying in the simplicity of JavavScript code.

Alfresco provides a nice feature rich JavaScript API (more here) where some of the objects are injected from scripting engine as root objects. These object provides the building blocks for JavaScript API e.g. search, user home, workflows etc. You can write your own Java services and inject them as root object using simple configuration to extend this foundation. Once your basic services are in place, then you can start knitting or wiring your business logic using these foundation blocks. JavaScript is an ideal choice as it expects small, working code instead of heavy logic which Java can handle. With small fluff of code you will be looking at some fantastic results.

I was amazed and surprised by the simplicity but there are few things which I needed to finalize before I decided to make a choice -

After all concerns are addressed, I was pretty sure I will be writing most of my business logic code and writing the services in JavaScript. I haven't stressed much in this post on view as its pretty standard freemarker template engine. I would like to touch upon that later.

If you are considering the Alfresco and writing your business logic in JavaScript (called as Web Scripts in Alfresco) then I would seriously recommend following things for reading/viewing -

Unfortunately, we wanted to book the cab on a 3 hours notice and it was mandatory for us to book the cab.  We couldn’t resist but started looking for options at our hand. We pulled the website in Firefox and opened firebug to see where the validation is executed. We were surprised by the validation was done in browser using a very simple JavaScript. We thought; let’s see if we could just pass the 4 hours validation by bypassing the validation or maybe mocking the action. The validation code was very simple; we just put the breakpoint in the function and then set the variable value via firebug to an acceptable level. Bang! The code ran successfully and cab service accepted the request.

We made a successful cab reservation and my friend could take a peaceful ride back home!  Moral of the story: Please put all the business critical validations on the server side instead of browser based JavaScript. If you really want to do some browser based validation then it will be really good idea to obfuscate the code.