# Sunday, 24 October 2010
Question: If you were given carte blanche to design a cloud platform, which database would you use?
Answer: This is a trick question since "none" is an acceptable answer.

In researching how to manage cached objects for the Cool Mesh project, I found this article on the High Availability blog "Are Cloud-Based Memory Architectures the Next Big Thing?" that articulates a lot of what I'm seeing in progressive cloud design.

Many high availability cloud platforms currently manage all reads and writes through memcached objects before persisting to a database. In some cases, the database write is done asynchronously while the cached object is trusted as authoritative. How can a database be called a system of record if the client is already proceeding on operations with a cached object before it hits the database? Dunno. It's only a matter of time before common sense prevails and we begin to manage in memory objects as the system of record and using disks as a backup or bootstrap index.

Now, would I let 100 people withdraw funds from a single bank account using this architecture? Probably not. A RAM system of record assumes some level of volatility, immutability, and non-transactional requirements.

I see this cloud architecture playing out in a couple phases:
1) RAM based architectures with system of record in memory, but still using disks for backup
2) Solid State Drive (SSD) based architectures that have memory I/O performance, but revert back to system of record on disk

The timing of each phase is largely driven by the cost and performance of SSDs. Cool Mesh is learning towards the phase 1 approach, but also makes use of HTML5 local storage for distribution of object storage, so no real benefit in waiting for phase 2 anyway.

Sunday, 24 October 2010 15:19:23 (Pacific Daylight Time, UTC-07:00)
# Saturday, 23 October 2010

Short Version: The rumors are true. I accepted a position at Facebook with a focus on Salesforce.

(That's about it. Read the long version for more details)

Long Version:
I started working at Facebook in August with a focus on designing and developing apps on Force.com within the IT group. The group is very focused on embracing cloud-based solutions to maintain agility and efficiency during a hyper-growth phase.

My wife and I moved from Portland, OR to San Carlos, CA as part of the transition and simply love it. We've actually been considering a move to Silicon Valley for 2 years for the weather, family, and, well... this is the center of cloud computing. The Facebook position gave us the perfect opportunity to make the jump.

Why Facebook? The 3 primary motivations for working at Facebook are the cloud, a progressive IT group, and company culture.

The Cloud
Facebook's infrastructure is one of the most under appreciated cloud architectures in existence today.

When you consider that Salesforce can support 1.5M customers on 1,000 servers (a 1,500:1 ratio) you understand why we are at an important inflection point in IT infrastructure and must consider cloud-based solution providers at every opportunity. Multi-tenancy is just much more efficient.

Then when I look internally at Facebook supporting 300M users on 30,000 servers (a 10,000:1 ratio) the efficiencies of scalable cloud-based architecture become even more obvious and impressive. (I'd love to share how we accomplish this feat, but you'll just have to apply here first :-). It truly is amazing and gets more efficient with each release)

Facebook as an enterprise class cloud provider will become even more apparent within 10 years as the user base grows and takes their social graph with them into every facet of their life (phones, devices, automobiles). When Mark Zuckerberg coined the term "social utility" back in 2007, the average response was "Huh?... It's just a website where I communicate with my friends".

But as the social graph gets consumed via web service APIs and millions of people communicate through the service, the role of Facebook (and the reasoning behind Mark's comment) becomes much more like an AT&T for the web rather than just a website.

The focus and dedication to cloud-computing is so serious, that we will build all our own datacenters from the ground up going forward, starting first in Prineville, OR.

Progressive Information Technology
I work in the IT group at Facebook in a ground floor opportunity at a rapidly growing company. We have an opportunity to learn from past enterprise IT architectures and challenge the norms using cloud computing and open source. The infrastructure put in place today will very likely still exist in 10+ years.

Unlike traditional IT roles, Facebook IT is responsible for the core product; our datacenters, servers, and technical operations. Our group is aligned very closely with the product Software Engineers.

Every IT asset; from CRM, ERP, Financials, HRM, SCM, ESB,... and a dozen other TLAs, are in it's first or second generation deployment. There are "build or buy" decisions being made constantly. My role often times involves demonstrating how to leverage what we've already "bought" (using Force.com for a variety of specific solutions).

Facebook takes a progressive stance on utilizing Salesforce as a platform and I've additionally been challenged with projects and opportunities that leverage my strengths outside just Salesforce development.

Culture
I'm probably the youngest 40 year old most people will ever meet still enjoy the occasional hackathon, drinking lots of coffee and embracing the most progressive idea or concept emerging at the time in software development.

There is no other company that I can think of than Facebook that is the epitome of this type of culture. There is a kindred spirit amongst all Engineers at Facebook that is hard to explain. I've participated in 2 hackathons so far and will never miss future events.

Most people don't perceive Facebook as a technology company, but the internal esprit de corps is very focused on building cool stuff, simply for the enjoyment of building stuff. Facebook is a technology company.

Side Projects
Maybe I'm being over ambitious to think I'll have any spare time to work on side projects, but here's a status of projects I continue to support and take great interest in on the side.

Passage .NET Portal Framework: This platform is still OEM'd by a couple partners who do the heavy lifting. The XOS framework has really proven that object oriented databases can be scalable and flexible. A couple more partners/resellers are in the process of developing Passage based solutions, so I don't think the end is in sight.

i-Dialogue: Other partners and associates have taken over the day to day hosting and support of i-Dialogue portals and sites. I still respond to any dlog related questions within 48 hours. Another developer has taken over all custom development, but I still enjoy occasionally optimizing the framework and have committed to participating in quarterly reviews/updates/patches.

Cool Sites: Similar to i-Dialogue, this native AppExchange app is primarily driven by partners. Cool Sites was developed to give my creative and web development friends (who rely primarily on HTML/CSS/JS skills) access to the rapidly growing Salesforce customer base.

There is a backlog of Cool Sites plugin requests that involve porting existing i-Dialogue components to Visualforce (Event calendar, knowledge base, shopping carts, partner finder, maps, etc...). Word on the street is that Salesforce acquired a CMS company and is preparing a similar offering for Dreamforce 2010, so I'm in "wait and see" mode re: the future of this project.

Cool Trends: I started this Salesforce native app after working with the Google Maps API on the Azure proof of concept app last Winter. It's a very simple data warehouse (only 2 custom objects) with time-series analysis charts for reporting day-over-day trends.

If time allows, I'll try to submit this to the AppExchange before Dreamforce 2010.

Cool Mesh: After years of designing and developing single-tenant enterprise web applications, the entrepreneur in me began to pursue the "next big thing". Cool Mesh is a massively scalable, multi-tenant, open-source, clustered computing project loosely based on the following ingredients:
  • Amazon EC2
  • Unix
  • Apache
  • Node.js
  • CouchDB / Cassandra
  • Immutable storage
Don't ask me what I'd do with a working prototype. Probably just re-invent business models I've worked on in the past :-)

Chatter Bot: On the heels of receiving an award for Chatter Bot, I started delving into "The Internet of Things" and envisioning what Cloud 3.0 might look like. An idea emerged, based on Cool Mesh, that continues to intrigue me. Still dabbling.

Music in Schools (non-profit):  I still support or volunteer for 3-5 non-profits on Salesforce and really believe in their vision. Immersing myself in a music education non-profit is where I'd like to start devoting my time next. I'm new to the bay area, so there's some research to do. Who knows; if I don't find a perfect NPO, then I'm open to launching one myself.

I'll be wandering the halls of Dreamforce 2010. Don't be a stranger. If you read this blog, then I hope we'll meet at the Tweetup :-)


Saturday, 23 October 2010 13:53:24 (Pacific Daylight Time, UTC-07:00)
# Monday, 26 July 2010
I missed the discussions on "open cloud" and "cloud standards" at OSCON 2010, but indirectly got the gist of it. Standards themselves aren't bad, but it's rarely a good idea to create a standard for the sake of just creating a standard.

I've observed 3 fundamental perspectives and their likely motivators on the issue of cloud standards:

1) Vendor: Invested $XXX million in software stack Y. Wants it proclaimed "standard" (for obvious reasons)
2) Developer: Wants "write once run everywhere" in the name of "portability" (doesn't want to learn 5 different APIs)
3) Consumer: Doesn't care. Wants it to "just work"

If you look across all cloud stacks today, what do you see that is common amongst them and could even remotely be called a "standard"? I see TCP/IP running on Intel x86 CPU architecture.

If someone told you 10 years ago "In order to democratize access to computing resources and enable ubiquitous access to information we all need to standardize on Intel x86 architecture and deliver services over IP", several people would have scoffed at that. It's incredible how far cloud computing has come as a "standard".

There is an art to minimizing standards in order to maximize adoption.

Look at electricity. For years there were debates over whether DC or AC power was better. The US finally standardized on a plug with 120V AC at 60Hz as a "standard" for electricity. 3 very simple data points that led to an explosion in adoption.

But look at the rest of the world. Different combinations of plugs, voltages, and frequencies abound! Fortunately these standards are all "open" and simple enough to allow for converters and transformers to fill the gaps. Fundamentally, the world really only agreed to standardize on alternating current (AC) at a range of voltages between 110-240 Volts. But for consumers, it "just works".

That's the way cloud computing is evolving. Building on the Internet (TCP/IP), running on servers (Intel x86), and bridging the gaps using a few basic tools (JSON, XML, SOAP, REST, CSV).

Check out Nicholas Carr's book "The Big Switch" for the back story on how industrial America moved towards standardized and centralized power utilities and how that parallels what's going on in cloud computing.

The Internet is called "the web" for a reason. It's in reference to its inherently chaotic data structure. Asserting standards to make sense of it won't help. It will only inhibit adoption. The web and cloud computing must be allowed to organically sprawl uninhibited.

Final thoughts:
1) Vendors: Explain to customers which specific primitive cloud services you offer (Windows/Linux, HTTP/SSL/SMTP/FTP) and preempt the discussion on integration by providing APIs to raw computing resources.
2) Developers: Sorry. The days of learning one language or standard are over. "Embrace the cloud!" The next killer app exists at the convergence of several cloud services (think mashups blending location, maps, social graph, consumer reviews, and merchant offers... all in one).
3) Customers: Sorry about the noise. We'll get this sorted out as soon as possible and ensure the cloud "just works". Thank you for your patience :-)


Monday, 26 July 2010 19:58:53 (Pacific Daylight Time, UTC-07:00)
# Saturday, 10 July 2010


Facebook has nearly 500 million users (at the time of this writing) and are poised to transform how customer relationships are acquired, cultivated, and supported.

Consider the evolution of Contact management over the past 50 years:
  • Paper: Write names, addresses, birthdays, and other notes down on paper
  • Rolodex: Everyone trades business cards and keeps a local paper copy
  • PC Software: Rolodex moved to PC (Spreadsheets, Goldmine, Act!)
  • Client / Server Software: Many people in same office share common contact database (Siebel, MS CRM)
  • Software as a Service: Contacts moved to Internet hosted server. Accessible from anywhere (Salesforce.com)
  • Crowd sourced: 3rd parties pooling contact information to improve data quality, keep lists up to date (Plaxo, Jigsaw)
  • Social Networking: Contact maintains singular identity. Always up to date. Control of privacy and disclosure (LinkedIn, Facebook)
The consumer now has more power than ever. Consumers now generate more information about themselves than can be generated by 3rd parties.

Buying a list of leads that may be interested in buying camping gear will have no where near the effectiveness of publishing an ad on Facebook targeted at consumers with a self-identified interest in camping (See The Role of Advertising at Facebook).

Consumers will increasingly defer to their friends recommendations on which restaurants to visit, which shoes to buy, and which cars to drive.

CRM systems no longer contain the master records for Contact information.

Businesses must evolve past collecting and cleansing Contacts and instead collect meta-information that refers to customer-managed online profiles, such as Facebook and LinkedIn, for these resources are now truly authoritative. When there is a conflict between CRM Contact information and an online social network profile, the social profile will be master record.

Websites must evolve to become applications. Web forms soliciting contact information will become a thing of the past. Consumers will not have the patience to do anything more than a single click to identify interest in a product or service.

The video embedded in this blog post (and available here) demonstrates a Cool Sites application integrated with Facebook Connect and Salesforce CRM.
Saturday, 10 July 2010 16:31:06 (Pacific Daylight Time, UTC-07:00)
# Thursday, 08 July 2010

No, not this Trigger... keep reading...

Trigger development (apologies to Roy Rogers' horse) is not done on a daily basis by a typical Force.com Developer.

In my case, Trigger development is similar to using regular expressions (regex) in that I often rely on documentation and previously developed code examples to refresh my memory, do the coding, then put it aside for several weeks/months.

I decided to create a more fluent Trigger template to address the following challenges and prevent me from repeatedly making the same mistakes:

  • Bulkification best practices not provisioned by the Trigger creation wizard
  • Use of the 7 boolean context variables in code (isInsert, isBefore, etc...) greatly impairs readability and long-term maintainability
  • Trigger.old and Trigger.new collections are not available in certain contexts
  • Asynchronous trigger support not natively built-in

The solution was to create a mega-Trigger that handles all events and delegates them accordingly to an Apex trigger handler class.

You may want to customize this template to your own style. Here are some design considerations and assumptions in this template:

  • Use of traditional event method names on the handler class (OnBeforeInsert, OnAfterInsert)
  • Maps are used where they are most relevant
  • Objects in map collections cannot be modified, however there is nothing in the compiler to prevent you from trying. Remove them whenever not needed.
  • Maps are most useful when triggers modify other records by IDs, so they're included in update and delete triggers
  • Encourage use of asynchronous trigger processing by providing pre-built @future methods.
  • @future methods only support collections of native types. ID is preferred using this style.
  • Avoid use of before/after if not relevant. Example: OnUndelete is simpler than OnAfterUndelete (before undelete is not supported)
  • Provide boolean properties for determining trigger context (Is it a Trigger or VF/WebService call?)
  • There are no return values. Handler methods are assumed to assert validation rules using addError() to prevent commit.

References:
Apex Developers Guide - Triggers
Steve Anderson - Two interesting ways to architect Apex triggers

AccountTrigger.trigger

trigger AccountTrigger on Account (after delete, after insert, after undelete, 
after update, before delete, before insert, before update) {
	AccountTriggerHandler handler = new AccountTriggerHandler(Trigger.isExecuting, Trigger.size);
	
	if(Trigger.isInsert && Trigger.isBefore){
		handler.OnBeforeInsert(Trigger.new);
	}
	else if(Trigger.isInsert && Trigger.isAfter){
		handler.OnAfterInsert(Trigger.new);
		AccountTriggerHandler.OnAfterInsertAsync(Trigger.newMap.keySet());
	}
	
	else if(Trigger.isUpdate && Trigger.isBefore){
		handler.OnBeforeUpdate(Trigger.old, Trigger.new, Trigger.newMap);
	}
	else if(Trigger.isUpdate && Trigger.isAfter){
		handler.OnAfterUpdate(Trigger.old, Trigger.new, Trigger.newMap);
		AccountTriggerHandler.OnAfterUpdateAsync(Trigger.newMap.keySet());
	}
	
	else if(Trigger.isDelete && Trigger.isBefore){
		handler.OnBeforeDelete(Trigger.old, Trigger.oldMap);
	}
	else if(Trigger.isDelete && Trigger.isAfter){
		handler.OnAfterDelete(Trigger.old, Trigger.oldMap);
		AccountTriggerHandler.OnAfterDeleteAsync(Trigger.oldMap.keySet());
	}
	
	else if(Trigger.isUnDelete){
		handler.OnUndelete(Trigger.new);	
	}
}

AccountTriggerHandler.cls

 
public with sharing class AccountTriggerHandler {
	private boolean m_isExecuting = false;
	private integer BatchSize = 0;
	
	public AccountTriggerHandler(boolean isExecuting, integer size){
		m_isExecuting = isExecuting;
		BatchSize = size;
	}
		
	public void OnBeforeInsert(Account[] newAccounts){
		//Example usage
		for(Account newAccount : newAccounts){
			if(newAccount.AnnualRevenue == null){
				newAccount.AnnualRevenue.addError('Missing annual revenue');
			}
		}
	}
	
	public void OnAfterInsert(Account[] newAccounts){
		
	}
	
	@future public static void OnAfterInsertAsync(Set<ID> newAccountIDs){
		//Example usage
		List<Account> newAccounts = [select Id, Name from Account where Id IN :newAccountIDs];
	}
	
	public void OnBeforeUpdate(Account[] oldAccounts, Account[] updatedAccounts, Map<ID, Account> accountMap){
		//Example Map usage
		Map<ID, Contact> contacts = new Map<ID, Contact>( [select Id, FirstName, LastName, Email from Contact where AccountId IN :accountMap.keySet()] );
	}
	
	public void OnAfterUpdate(Account[] oldAccounts, Account[] updatedAccounts, Map<ID, Account> accountMap){
		
	}
	
	@future public static void OnAfterUpdateAsync(Set<ID> updatedAccountIDs){
		List<Account> updatedAccounts = [select Id, Name from Account where Id IN :updatedAccountIDs];
	}
	
	public void OnBeforeDelete(Account[] accountsToDelete, Map<ID, Account> accountMap){
		
	}
	
	public void OnAfterDelete(Account[] deletedAccounts, Map<ID, Account> accountMap){
		
	}
	
	@future public static void OnAfterDeleteAsync(Set<ID> deletedAccountIDs){
		
	}
	
	public void OnUndelete(Account[] restoredAccounts){
		
	}
	
	public boolean IsTriggerContext{
		get{ return m_isExecuting;}
	}
	
	public boolean IsVisualforcePageContext{
		get{ return !IsTriggerContext;}
	}
	
	public boolean IsWebServiceContext{
		get{ return !IsTriggerContext;}
	}
	
	public boolean IsExecuteAnonymousContext{
		get{ return !IsTriggerContext;}
	}
}
Thursday, 08 July 2010 14:16:12 (Pacific Daylight Time, UTC-07:00)
# Tuesday, 29 June 2010
There are really only 2 tech blogs that I read; TechCrunch.com and ReadWriteWeb.com (RWW). They both provide balanced coverage of the consumer and enterprise markets while remaining objective. You don't get the sense that site sponsors and advertisers are driving the stories. I admire their integrity.

I've been particularly impressed with RWW's coverage on the cloud and the Internet of Things, so I was absolutely thrilled when Alex Williams ran with a story yesterday about Chatter Bot titled "How to Connect an Office Building to an Activity Stream". Check it out! (A hint on the title of this blog :-) )

Tuesday, 29 June 2010 11:32:15 (Pacific Daylight Time, UTC-07:00)
# Thursday, 24 June 2010

Chatter Developer Challenge / Hackathon 2010 Roundup

The Chatter Developer Challenge sponsored by Salesforce encouraged Developers to create a wide variety of applications that demonstrate the new Salesforce Chatter API.

The challenge culminated in a Hackthon event on June 22nd 2010 at the San Jose Convention Center where prizes were awarded for various applications.

My entry, Chatter Bot, demonstrated the use of Chatter within a Facility Management application that captured physical world events and moved them to the cloud to produce Chatter feed posts.

Chatter Bot is a system comprised of 4 major components:

  • Arduino board with motion and light sensors (C/C++)
  • Proxy Service (Java Processing.org Environment)
  • Salesforce Sites HTTP Listener (Visualforce/Apex)
  • Facility Management App (Force.com database and web forms)
(Source code to all components available at the bottom of this post)

I was elated to learn a few days before the hackathon that Chatter Bot had been selected as a finalist and I was strongly encouraged to attend. So I packed up Chatter Bot to take the 2 hour flight from Portland to San Jose.

It wasn't until I arrived at the airport that it suddenly dawned on me how much Chatter Bot bares a striking resemblance to a poorly assembled explosive device. Apparently the TSA agent handling the X-Ray machine thought so too and I was taken aside for the full bomb sniffing and search routine.

It crossed my mind to add a bit levity to the situation by making some kind of remark, but I quickly assessed that I was probably one misinterpreted comment away from being whisked off in handcuffs to some TSA lockup room. Ironically, I had no problem with security in San Jose coming back. They must be accustomed to these types of devices in Silicon Valley.

Upon arriving in San Jose, I setup Chatter Bot and configured the San Jose Convention Center (SJCC) as a Building Facility (Custom object) to be monitored.

Several assets were created to represent some rooms within the SJCC.

Finally, the Chatter Bot was associated with a particular room (Asset) through an intersection object called AssetSensors that relates a device ID (usually a MAC address) and an Asset.

Within minutes the motion and light sensors were communicating to the cloud via my laptop and reporting on activity in the Hackathon room.

Given the high quality and functionality of fellow competitors apps, such as the very cool Chatter for Android app by Jeff Douglas, and observations from the public voting, I thought Chatter Bot might be a little too "out of the box" to take a prize. It was a genuinely surreal and surprising moment when I learned Chatter Bot received the grand prize.

Thank you Salesforce for hosting such a great event and thank you to the coop-etition for the encouraging exchange of ideas and feedback during the challenge!

Arduino Sensor

/////////////////////////////
//VARS
//the time when the sensor outputs a low impulse
long unsigned int lowIn;

//the amount of milliseconds the sensor has to be low 
//before we assume all motion has stopped
long unsigned int pause = 5000;

boolean lockLow = true;
boolean takeLowTime;  

int LDR_PIN = 2;    // the analog pin for reading the LDR (Light Dependent Resistor)
int PIR_PIN = 3;    // the digital pin connected to the PIR sensor's output
int LED_PIN = 13;

byte LIGHT_ON    = 1;
byte LIGHT_OFF   = 0;
byte previousLightState  = LIGHT_ON;
int lightLastChangeTimestamp = 0;
unsigned int LIGHT_ON_MINIMUM_THRESHOLD = 1015;
unsigned long lastListStateChange = 0; //Used to de-bounce borderline transitions.

// Messages
int SENSOR_MOTION = 1;
int SENSOR_LIGHT  = 2;

/////////////////////////////
//SETUP
void setup(){  
  //PIR initialization
  pinMode(PIR_PIN, INPUT);
  pinMode(LED_PIN, OUTPUT);
  digitalWrite(PIR_PIN, LOW);
  
  Serial.begin(9600);
  
  InitializeLED();
  InitializeLightSensor();
  InitializeMotionSensor();
}

////////////////////////////
//LOOP
void loop(){
  
  if(digitalRead(PIR_PIN) == HIGH){
    digitalWrite(LED_PIN, HIGH);   //the led visualizes the sensors output pin state
    if(lockLow){
      //makes sure we wait for a transition to LOW before any further output is made:
      lockLow = false;
      writeMeasure(SENSOR_MOTION, HIGH);
      delay(50);
      digitalWrite(LED_PIN, LOW);   //the led visualizes the sensors output pin state
    }
    takeLowTime = true;
  }

  if(digitalRead(PIR_PIN) == LOW){
    digitalWrite(LED_PIN, LOW);  //the led visualizes the sensors output pin state
    if(takeLowTime){
      lowIn = millis();          //save the time of the transition from high to LOW
      takeLowTime = false;       //make sure this is only done at the start of a LOW phase
    }
    
    //if the sensor is low for more than the given pause, 
    //we assume that no more motion is going to happen
    if(!lockLow && millis() - lowIn > pause){
      //makes sure this block of code is only executed again after 
      //a new motion sequence has been detected
      lockLow = true;
      writeMeasure(SENSOR_MOTION, LOW);
      delay(50);
    }
  }
  
  ProcessLightSensor();
}

boolean InitializeLED(){
  Serial.println("INIT: Initializing LED (should see 3 blinks)... ");
  for(int i=0; i < 3; i++){
    digitalWrite(LED_PIN, HIGH);
    delay(500);
    digitalWrite(LED_PIN, LOW);
    delay(500);
  }
}

//the time we give the motion sensor to calibrate (10-60 secs according to the datasheet)
int calibrationTime = 10;

boolean InitializeMotionSensor(){
  //give the sensor some time to calibrate
  Serial.print("INIT: Calibrating motion sensor (this takes about ");
  Serial.print(calibrationTime);
  Serial.print(" seconds) ");
  for(int i = 0; i < calibrationTime; i++){
    Serial.print(".");
    delay(1000);
  }
  Serial.println(" done");
  Serial.println("INIT: SENSOR ACTIVE");
  delay(50);
}

boolean InitializeLightSensor(){
  Serial.print("INIT: Initializing light sensor. Light on threashold set to ");
  Serial.println(LIGHT_ON_MINIMUM_THRESHOLD);
  Serial.println("INIT: 20 samples follow...");
  for(int i = 0; i < 20; i++){
    int lightLevelValue = analogRead(LDR_PIN);
    Serial.print("INIT: ");
    Serial.println(lightLevelValue);
  }
}

boolean ProcessLightSensor(){
  byte currentState = previousLightState;
  int lightLevelValue = analogRead(LDR_PIN);  // returns value 0-1023. 0=max light. 1,023 means no light detected.
  
  if(lightLevelValue < LIGHT_ON_MINIMUM_THRESHOLD){
     currentState = LIGHT_ON;
  }
  else{
     currentState = LIGHT_OFF;
  }
  
  if(LightStateHasChanged(currentState) && !LightStateIsBouncing() ){
    previousLightState = currentState; 
    
    if(currentState == LIGHT_ON){
      writeMeasure(SENSOR_LIGHT, HIGH);
    }
    else{
      writeMeasure(SENSOR_LIGHT, LOW);
    }
    
    delay(2000);
    lightLastChangeTimestamp = millis();
    
    return true;
  }
  else{
    return false; 
  }
}

boolean LightStateHasChanged(byte currentState){
   return currentState != previousLightState; 
}

//De-bounce LDR readings in case light switch is being quickly turned on/off
unsigned int MIN_TIME_BETWEEN_LIGHT_CHANGES = 5000;
boolean LightStateIsBouncing(){
   if(millis() - lightLastChangeTimestamp < MIN_TIME_BETWEEN_LIGHT_CHANGES){
      return true; 
   }
   else{
      return false; 
   }
}

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; 
char deviceID[ ] = "007DEADBEEF0";
//Format MEASURE|version|DeviceID|Sensor Type|State (on/off)
void writeMeasure(int sensorType, int state){
  Serial.print("MEASURE|v1|");
  
  Serial.print(deviceID);
  Serial.print("|");
  
  if(sensorType == SENSOR_MOTION)
    Serial.print("motion|");
  else if(sensorType == SENSOR_LIGHT)
    Serial.print("light|");
  else
    Serial.print("unknown|");
  
  if(state == HIGH)
    Serial.print("on");
  else if(state == LOW)
    Serial.print("off");
  else
    Serial.print("unknown");
  
  Serial.println("");
}

Chatter Bot Proxy (Processing.org Environment)

import processing.serial.*;

Serial port;
String buffer = "";

void setup()
{
    size(255,255);
    println(Serial.list());
    port = new Serial(this, "COM7", 9600);
}

void draw()
{
  if(port.available() > 0){
    int inByte = port.read();
    print( char(inByte) );
    if(inByte != 10){ //check newline
      buffer = buffer + char(inByte);
    }
    else{
       if(buffer.length() > 1){
          if(IsMeasurement(buffer)){
              postToForce(buffer);
          }
          buffer = "";
          port.clear();
       }
    }
  }
}

boolean IsMeasurement(String message){
  return message.indexOf("MEASURE") > -1;
}

void postToForce(String message){
  String[] results = null;
  try
  {
    URL url= new URL("http://listener-developer-edition.na7.force.com/api/measure?data=" + message);
    URLConnection connection = url.openConnection();

    connection.setRequestProperty("User-Agent",  "Mozilla/5.0 (Processing)" );
    connection.setRequestProperty("Accept",  "text/plain,text/html,application/xhtml+xml,application/xml" );
    connection.setRequestProperty("Accept-Language",  "en-us,en" );
    connection.setRequestProperty("Accept-Charset",  "utf-8" );
    connection.setRequestProperty("Keep-Alive",  "300" );
    connection.setRequestProperty("Connection",  "keep-alive" );
    
    results = loadStrings(connection.getInputStream());  
  }
  catch (Exception e) // MalformedURL, IO
  {
    e.printStackTrace();
  }

  if (results != null)
  {
    for(int i=0; i < results.length; i++){
      println( results[i] );
    }
  }
}

Visualforce Site Chatter Listener

<apex:page controller="measureController" action="{!processRequest}" 
contentType="text/plain; charset=utf-8" showHeader="false" 
standardStylesheets="false" sidebar="false">
{!Result}
</apex:page>

Controller

public with sharing class measureController {
	public void processRequest(){
    	if(Data != null){
    		system.debug('data= ' + Data);
    	}
    	
    	CreateFeedPosts();
    }
    
    private void CreateFeedPosts(){
    	if(AssetDeviceBindings.size() == 0)
    		return;
    	
    	for(AssetSensor__c binding : AssetDeviceBindings){
	    	FeedPost newFeedPost = new FeedPost();
	    	newFeedPost.parentId = binding.Asset__c;
			newFeedPost.Type = 'TextPost';
	        newFeedPost.Body = FeedPostMessage();
	        insert newFeedPost;
    	}
    }
    
    private string FeedPostMessage(){
    	if(AssetDeviceBindings.size() == 0)
    		return '';
    	
    	if(SensorType == 'motion'){
    		if(State == 'on')
    			return 'Motion detected';
    		else
    			return 'Motion stopped';
    	}
    	else if(SensorType == 'light'){
    		return 'Lights turned ' + State;
    	}
    	else
    		return 'Unknown sensor event';
    }
    
    private List<AssetSensor__c> m_assetSensor = null;
    public List<AssetSensor__c> AssetDeviceBindings{
    	get{
    		if(m_assetSensor == null){
    			m_assetSensor = new List<AssetSensor__c>();
    			if(DeviceID != null){
    				m_assetSensor = [select Id, Name, Asset__c, DeviceID__c from AssetSensor__c where DeviceID__c=:DeviceID limit 500];
    			}
    		}
    		return m_assetSensor;
    	}
    }
    
    private integer EXPECTED_MESSAGE_PARTS = 5;
    private integer DATA_MESSAGE_TYPE = 0;
    private integer DATA_VERSION	= 1;
    private integer DATA_DEVICEID	= 2;
    private integer DATA_SENSOR_TYPE= 3;
    private integer DATA_STATE		= 4;
    
    private List<string> m_dataParts = null;
    public List<string> DataParts{
    	get{
    		if(m_dataParts == null && Data != null){
    			m_dataParts = Data.split('\\|');
    		}
    		return m_dataParts;
    	}
    }
    
    public string Version{
    	get{
    		if(Data != null && DataParts.size() >= EXPECTED_MESSAGE_PARTS){
    			return DataParts[DATA_VERSION];
    		}
    		else
    			return null;
    	}
    }
    
    public string DeviceID{
    	get{
    		if(Data != null && DataParts.size() >= EXPECTED_MESSAGE_PARTS){
    			return DataParts[DATA_DEVICEID];
    		}
    		else
    			return null;
    	}
    }
    
    public string SensorType{
    	get{
    		if(Data != null && DataParts.size() >= EXPECTED_MESSAGE_PARTS){
    			return DataParts[DATA_SENSOR_TYPE];
    		}
    		else
    			return null;
    	}
    }
    
    public string State{
    	get{
    		if(Data != null && DataParts.size() >= EXPECTED_MESSAGE_PARTS){
    			return DataParts[DATA_STATE];
    		}
    		else
    			return null;
    	}
    } 
    
    private string m_data = null;
    public string Data{
    	get{
    		if(m_data == null && ApexPages.currentPage().getParameters().get('data') != null){
    			m_data = ApexPages.currentPage().getParameters().get('data');
    		}
    		return m_data;
    	}
    }
    
    private string m_result = '';
    public String Result{
    	get{
    		return 'ok';
    	}
    }
    
    public static testMethod void tests(){
    	Asset testAsset = new Asset();
    	testAsset.Name = 'Test Asset';
    	testAsset.AccountID = [select Id from Account order by CreatedDate desc limit 1].Id;
    	insert testAsset;
    	
    	AssetSensor__c binding = new AssetSensor__c();
    	binding.Name = 'Test Binding';
    	binding.DeviceID__c = '007DEADBEEF9';
    	binding.Asset__c = testAsset.Id;
    	insert binding;
    	
    	measureController controller = new measureController();
    	controller.processRequest();
    	system.assert(controller.Data == null);
    	system.assert(controller.DataParts == null);
    	system.assert(controller.Version == null);
    	system.assert(controller.DeviceID == null);
    	system.assert(controller.SensorType == null);
    	system.assert(controller.State == null);
    	
    	string TEST_MEASURE = 'MEASURE|v1|007DEADBEEF9|motion|on';
    	ApexPages.currentPage().getParameters().put('data', TEST_MEASURE);
    	controller = new measureController();
    	controller.processRequest();
    	system.assert(controller.Data == TEST_MEASURE);
    	system.assert(controller.DataParts != null);
    	system.assert(controller.DataParts.size() == 5);
    	system.assert(controller.Version == 'v1');
    	system.assert(controller.DeviceID == '007DEADBEEF9');
    	system.assert(controller.SensorType == 'motion');
    	system.assert(controller.State == 'on');
    	
    	system.assert(controller.AssetDeviceBindings != null);
    	system.assert(controller.AssetDeviceBindings.size() == 1);
    	system.assertEquals('007DEADBEEF9', controller.AssetDeviceBindings[0].DeviceID__c);
    	system.assertEquals(testAsset.Id, controller.AssetDeviceBindings[0].Asset__c);
    	
    	system.assert(controller.Result == 'ok');
    }
}
Thursday, 24 June 2010 18:03:10 (Pacific Daylight Time, UTC-07:00)
# Monday, 21 June 2010
I'm very happy to announce that Cool Sites was released this weekend. Cool Sites provides a gallery of pre-built page templates, plugins, and sites built on Salesforce Sites.

Basic web content management tools and workflows for creating navigation menus and web pages are included. Check it out! http://www.getcoolsites.com


Monday, 21 June 2010 15:43:39 (Pacific Daylight Time, UTC-07:00)
# Sunday, 13 June 2010

Jazz - A Software Development Methodology


What
Jazz is a software development methodology for the ongoing creation and improvisation around several small apps distributed on open Internet platforms (the "cloud").


Why
Contemporary tools, languages, and distribution platforms of the 21st century make it feasible for software to be created, delivered, and performed similarly to Jazz music of the 20th century.

Software, like music, may be consumed repeatedly throughout the day by audiences.

Software has become ubiquitous and essential to people's everyday lives.

Audiences increasingly are demanding to know more about the personalities and teams behind their favorite software applications.


What (Apps)
Jazz combos seek to build a repertoire of several small apps, as opposed to developing and supporting one large app. Jazz is most suitable for Developers distributing applications through online stores (such as the Apple App Store, Google Marketplace, or Salesforce AppExchange).

The repertoire should consist of at least 10 apps.

Not all apps are for commercial distribution (such as contributions to open source frameworks and proof of concept apps used for marketing purposes).

Only 1 in 10 apps within the repertoire will achieve any significant amount of notoriety or market adoption.


Who (The Combo)
Apps are initially composed by a single person, which are then rehearsed and performed by combos of up to 5-7 people. Apps are occasionally composed by 2 collaborators.

Apps are consumed by audiences (customers).


Where (Spaces)
Jazz is composed, rehearsed, and performed in 3 distinct "spaces".

Composition and practice are done in solitude (home, coffee shop, the beach) but always connected (anywhere with Internet access)

Rehearsals are done with a group about once per week in public meeting places

Performances are ongoing. They occur both virtually and physically. All audience interactions are performances (this includes app store listings, webinars, support, and customizations)


When
Jazz is not a 9 to 5 job. However, ongoing performances are typically supported by someone during working hours.

Jazz Developers dedicate at least 3 days per week to uninterrupted work (composition and improvisation) and at least 1 day for group rehearsals (meetings) and audience interactions (support and review of customer feedback).

Compositions may take 1 day or 1 year to write. It should take no more than 2 years to accumulate a repertoire of 10 apps.

Team members are often given "the floor" during performances to lead and improvise within a composition. Improvisations are short creative cycles within the overall structure of a composition.


How
Each member of a Jazz combo owns and maintains their own instruments (tools) that best support their function within the combo.

Academic mastery of instrument and language are assumed before confidence in composition and improvisation can be achieved.

Jazz combos are unified in language presented to audiences, but individually use languages specific to their instrument or function.

Jazz encourages the sharing, remixing, and reuse of ideas through use of creative commons licenses.

All individuals are given public recognition for their contribution to an app.

Performers may practice up to 10 hours for a 1 hour performance (10:1 ratio of effort, unit tests behind released products).

The best performances are achieved through mastery of instrument, confidence in skills, and relaxation of mind.

The result is more important than the means. Don't over think the process to achieving a good performance.

Improvisations often rely on audience feedback to determine the path of a performance.

The Jazz combo may dynamically adjust composition structure during a performance through subtle communication to support an improvisation that may lead to new discoveries or increased levels of audience feedback and participation.
Sunday, 13 June 2010 13:04:29 (Pacific Daylight Time, UTC-07:00)
# Monday, 07 June 2010

Here's a fun video put together for my Salesforce Chatter Developer Challenge entry.

Monday, 07 June 2010 09:57:05 (Pacific Daylight Time, UTC-07:00)