I’ve had a developer account for some time now, and the talk finally got me motivated into messing around with more of the APIs.  So I created a bot.  Then I created another one.  Because the first one didn’t do anything.

1.  Get Eclipse

So far, the choices for creating Google bots are rather limited because there are rules that they must be hosted on AppEngine (for now).   So first off, get Eclipse – because it makes the entire process of doing that incredibly easy.  You can download Eclipse here.

2.  Get the AppEngine SDK.

Once you’ve got Eclipse installed and running, go to Help -> Install New Software.  Enter this URL to get at the Google AppEngine SDK.

http://dl.google.com/eclipse/plugin/3.5

3.  Create your project.

Go to File->New, and select Web Application Project.  If you don’t have that option, something’s gone wrong with your SDK download, so check step 2.

Uncheck the Googe Web Toolkit, we don’t need that.  But otherwise fill out the Project Name and Package as you see fit.

4.  Add the libraries from the Wave extensions SDK

Download wave-robots-api.jar, json.jar, and jsonrpc.jar and drop those into your project under war/WEB-INF/lib/.

Once you’ve done that, select File->Refresh, then Project->Properties from the main menu, and select Java Build Path.  Click Libraries, and Add JARs, to select the three that you’ve just added.

5.  Write your servlet class.

This is where the bulk of your bot logic (or lack of it), goes.

Code block

package helloworld;
import com.google.wave.api.*;
public class HelloWorldServlet extends AbstractRobotServlet {
	public void processEvents(RobotMessageBundle bundle) {
		for (Event e: bundle.getEvents()) {
			if (e.getType() == EventType.BLIP_SUBMITTED) {
			Blip blip = e.getBlip().createChild();
			TextView textView = blip.getDocument();
			textView.append("Hello.  Are you the world?");
			break;
			}
		}
	}
}

6. Add a servlet mapping.

Edit the file, war/WEB-INF/web.xml and add a servet-mapping just below the one you have already.

Code block

<servlet-mapping>
<servlet-name>HelloWorld<servlet-name>
<url-pattern>/_wave/robot/jsonrpc</url-pattern>
</servlet-mapping>

7. Add a capabilities file.

Add a folder under war/_wave. Create a file under that called capabilities.xml. This tells Wave which events your robot is going to respond to. In our case, we’re going to respond whenever a blip is saved (blip_submitted)./ There is a full list of capabilities in the full api docs.

Code block

<?xml version="1.0" encoding="utf-8"?>
<w:robot xmlns:w="http://wave.google.com/extensions/robots/1.0">
<w:capabilities>
<w:capability name="BLIP_SUBMITTED" content="true" />
</w:capabilities>
<w:version>3</w:version>
</w:robot>

8.  Get an AppEngine account.

That kind of finishes off the Wave-bot.  So you’ll need an AppEngine account to continue.  So go ahead and sign up, and create an application.  Incidently, I couldn’t find my created apps since I have a Google Apps / Domain account.  if that’s the case for you as well, you can find your apps list at http://appengine.google.com/a/<domain>.  Not sure why Google don’t detect that, but there we go.

9.  Deploy to AppEngine

Click the friendly little icon from your Eclipse toolbar, and enter your details to deploy you new robot.  Try not to scream “fly my pretties” as you do so.  I dare you.  Make sure you click the App Engine Project Settings button, and provide you Application ID, the same as you created in step 8.

10.  Add your app to a wave

The address of your robot will be applicationid@appspot.com, and you can add it just like any other robot.

You should now be able to interact with your bot.

And if you’d like to see my first bot in action – please drop in and say hello by adding it to your wave: insulteveryone@appspot.com.

Now. World peace.  Where did I leave that file?

Unfortunately, this is one plugin that hasn’t been updated in quite a while (after all, if ain’t broke…), so it broke. Being the sort of developer that’s quite happy to pick up a block of php and hack it until it works, I stumbled across this blog entitled ‘Amazon® AWS HMAC signed request using PHP‘, which has a function to download.

So to fix AMM:

1. Download that file, and copy the contents into the bottom of amm_parser.php.

2. In the same file (amm_parser.php), replace your _setUrl function with this one:

Code block

function &_setUrl() {
	//Build URL from base URL and other required parameters
	switch ($this->_locale) {				
		case 'uk':
			$region = 'co.uk';
			break;
		case 'de':
			$region .= 'de';
			break;
		case 'jp':
			$region .= 'co.jp';
			break;
		case 'fr':
			$region .= 'fr';
			break;
		case 'ca':
			$region .= 'ca';
			break;
		case 'us':
		default:
			$region = 'com';
			break;
	}
	$public_key = "< < Your Access Key ID >>";
	$private_key = "< < Your Secret Access Key >>";
	$url = aws_signed_request($region, array(
			"Operation"=> "ItemSearch",
			"Keywords" => $this->_parameters[Keywords],
			"ResponseGroup"=>$this->_parameters[ResponseGroup],
			"SearchIndex" => $this->_parameters[SearchIndex],
			"AssociateTag" => urlencode($this->_associate_tag)),
			$public_key, $private_key);
	return $url;
}

3. Oddly enough, this new method requires a private secret key which Amazon recommends to not give to anyone. So I’m not going to post mine here, even though it’s required for the plugin to work. So before I ponder that particular nugget of madness, you’ll need to sign up for an AWS developer account, and find your own keys via the Access Identifiers page. These need to be added into the function above.

That should be enough to get you back up and running again, although selfishly I’ve only really tested it for my needs alone. So please let me know if it works, or fails miserably.

For all the legal bits, I’m not at all affiliated with Amazon or Sozu – so please use at your own risk

Query Syntax

Code block

var products = from audio in DbContext.DataContext.ProductAudios
join product in DbContext.DataContext.ProductAudios on audio.ProductId equals product.ProductId
select new { Product = product, Audio = audio };

Lambda Syntax

Code block

var products = DbContext.DataContext.ProductAudios.Join(
                DbContext.DataContext.Products,
                audio => audio.ProductId,
                product => product.ProductId,
                (audio, product) => new { Product = product, Audio = audio });

It might look like more code because of my formatting, but I find the lambda syntax much convenient when chaining queries together with other where’s and groupby’s, especially when that might be split across different methods. It also isolates your join nicely, whereas I find the query syntax will start to get particularly unreadable with more complex queries.

Last but not least, another piece of linq-join-related syntax I’m finding myself always having to look up a lot is for left outer joins. Fortunately I always end up at MSDN for that one, so I’ll just link to it here:
How to: Perform Left Outer Joins

Useful, but still just as simple as the previous examples, that is. Again – you’ll need your references from the downloaded IronRuby bin/ folder. And as you’ve come to expect, a very simple ruby script defining a lambda function.

Code block

$m = lambda {
            a = Array.new
            a.push(2, 3)
            (4..50).each do
               |i|
               (2..(Math.sqrt(i).ceil)).each do
                  |thing|
                  if (i.divmod(thing)[1] == 0)
                     a.push i
                     break
                  end
               end
            end
            return a
         }

From this, we’ll get an array of the prime numbers. The function can then be executed rather nicely from within your .NET code like this:

Code block

var ruby = Ruby.GetEngine(Ruby.CreateRuntime());
ruby.Execute(@"
    $m = lambda {
//.. snip..
            return a
         }
");
var rubyContext = Ruby.GetExecutionContext(ruby);
var m = (Proc)rubyContext.GetGlobalVariable("m");
var rubyArray = (RubyArray) m.Call();
foreach (var o in rubyArray)
{
    Console.Write(string.Format("{0},", o));
}

Now we’re really starting to leverage that syntactical beauty of ruby within .NET and jumping (almost) seamlessly between the two. Now, I really should do some demos on something more useful than prime numbers, and perhaps get into one of the big areas of interest of Ruby – testing frameworks. Not tonight though

Demo project available as usual:

• Download C# IronRuby Method Wrapper

So, this still serves as an example of how simple it can be to run ruby scripts within .NET. We’ll get to making use of some return values, and running individual methods in the next post.

Following on from the last example, the following ruby script prints all the prime numbers between 1 and 50.

Code block

state = Numeric.new
print "2,3,"
(4..50).each do
   |i|
   (2..(Math.sqrt(i).ceil)).each do
      |thing|
      state = 1
      if (i.divmod(thing)[1] == 0)
         state = 0
         break
      end
   end
   print "#{i}\," unless (state == 0)
end

With the ruby script complete (you can also run this with the ir.exe that ships with IronRuby if you like)… Next start up a new project within Visual Studio, and add some references from your downloaded IronRuby bin folder (IronRuby.dll, IronRuby.Libraries.dll etc…).

You only need a few lines of code to execute your ruby script.

Code block

using IronRuby;
// ..
var runtime = Ruby.CreateRuntime();
runtime.ExecuteFile(@"ruby/run.rb");

As before, you can download the full example to check it and run for yourself. And also as before, you will also need IronRuby.

• Download C# IronRuby Wrapper

Whilst my example below is extremely trivial, it shows how you might make use of any existing libraries within your Ruby scripts. This same technique applies to any .NET libraries, whether they’re custom, part of the framework, or created by your gran. I don’t think I really need to sell it in – but I love the flexibility that this provides.

So to get to the example, this simple piece of C# displays all the prime numbers between 0 and maxNumber:

Code block

public int[] DisplayPrimeNumbers(int maxNumber)
{
    int max = maxNumber;
    List previousPrimes = new List();
    previousPrimes.Add(2);
    if (max < 2) return null; // none
    for (int i = 3; i  maxDivisor) break;
            if ((i % previousPrimes[j]) == 0)
            {
                foundDivisor = true;
            }
        }
        if (!foundDivisor)
        {
            previousPrimes.Add(i);
        }
    }
    return previousPrimes.ToArray();
}

We can build that up into a class library and using IronRuby, manipulate the return of the method the same as though we had been running native ruby.

Code block

require 'mscorlib'
require 'CSharpLib, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null';
prime_numbers = CSharpLib::PrimeNumbers.new
(prime_numbers.DisplayPrimeNumbers 20).each do |num|
	puts num
end

You can download the full sample below, a C# console app is also included for completeness (although isn’t a part of the IronRuby process). You will of course, need to download IronRuby first, and add the installed bin/ folder to your path. Then just change to the <sample>/ruby/ directory, and run it with:

ir run.rb

• Download IronRuby / C# prime number sample

It’s probably worth noting that IronRuby is still a way off from a 1.0 release, but it’s already very usable and looking rather cool. Since it’s on my recent //TODO list, I’ll be doing a few more examples here – next time turning this one its head and executing your ruby scripts from within C#. In the meantime, you can check out Ben’s set of slides from Wednesday on Slideshare.

So all of these are technologies, packages, or platforms I want to be checking out in the not-to-distant future.  In no particular order, they’re bound to be added to as I go and quite possibly ignored as well.

• .NET
  • ASP.NET MVC
  • ADO.NET Data Services
  • F#
  • IronRuby
  • Open-sourcing a simple XML resource provider (CodePlex)
  • .NET 4
    • Windows Communication Foundation
    • Entity Framework
    • Parallel Extensions
• Gallery3
  • Module development
    • Migrate Twitter module
    • Migrate auto-GPS-tagging module
  • Theme development
• Google Wave

The API wraps up a lot of the Gallery2 remote services into some easy to use C# functions.

Code block

Actions a = new SADev.Gallery2.Protocol.Actions("http://www.blakepics.com");
string authToken = a.Login("*************", "*************").AuthToken;
a.FetchAlbums(authToken).Albums.ForEach(
    album =>
    {
        Console.WriteLine(album.Title);
        a.FetchImages(authToken, album.Name).Images.ForEach(image =>
            Console.WriteLine("\t" + image.Url)
        );
    }
    );
Console.ReadKey();

Hopefully I’ll find an excuse to use this one day.

Getting at your reports consists of two parts, firstly – use the Document ID (long) you got from posting the XML in the first place.

Code block

public DocumentProcessingInfo DocumentStatus(long DocumentID)
    {
        //Setup the service interface, set the URL of the service
        //and add our credentials.
        merchantinterfacedime myAmazon =
            new merchantinterfacedime();
        myAmazon.Url = ConfigurationManager.AppSettings["URL"];
        myAmazon.Credentials =
            new NetworkCredential(
                ConfigurationManager.AppSettings["UserName"],
                ConfigurationManager.AppSettings["Password"]);
        //Setup our merchant details.
        Merchant myMerchant = new Merchant();
        myMerchant.merchantIdentifier =
            ConfigurationManager.AppSettings["MerchantIdentifier"];
        myMerchant.merchantName =
            ConfigurationManager.AppSettings["MerchantName"];
        //Send it all off to Amazon.
        DocumentProcessingInfo myStatus =
            myAmazon.getDocumentProcessingStatus(
            myMerchant, DocumentID);
        //Return the status of the document.
        return myStatus;
    }

This will give you the status of your upload, as well as whether it’s complete or not. It also gives you another document ID, which you can use to get at your much-needed reports.

Code block

public string GetDocument(string id) {
        StringBuilder report = new StringBuilder();
        merchantinterfacedime myAmazon =
            new merchantinterfacedime();
        myAmazon.Url = ConfigurationManager.AppSettings["URL"];
        myAmazon.Credentials =
            new NetworkCredential(
                ConfigurationManager.AppSettings["UserName"],
                ConfigurationManager.AppSettings["Password"]);
        //Setup our merchant details.
        Merchant myMerchant = new Merchant();
        myMerchant.merchantIdentifier =
            ConfigurationManager.AppSettings["MerchantIdentifier"];
        myMerchant.merchantName =
            ConfigurationManager.AppSettings["MerchantName"];
        ReferencedBinary incomingDoc = new ReferencedBinary();
        // the seven-digit string is the document ID number
        myAmazon.getDocument(myMerchant, id, out incomingDoc);
        IEnumerator enumer = myAmazon.ResponseSoapContext.Attachments.GetEnumerator();
        while (enumer.MoveNext())
        {
            // Print the document to standard out
            Attachment downloadedDoc = enumer.Current as Attachment;
            StreamReader r = new StreamReader(downloadedDoc.Stream);
            report.Append(r.ReadToEnd());
        }
        return report.ToString();
}

And tying it all together:

Code block

long amazonId = #######
string report = GetDocument(DocumentStatus(amazonId).processingReport.documentID);

Your report will be in XML, and give you any validation errors that might be preventing your feed from working properly, as well as some very helpful status on the number of items processed. How did you ever live without it?

No it’s not.

It’s a micro-blogging tool which performs about the same function as your Facebook status, with a bit more history and more conversation potential than real speaking. It also falls into the category of “shiny web things” that the magpie’s of the Internet world run bounding towards with wings flapping, declaring their undying allegiance and overwhelming excitement about the grand new era of technology, society and communication.

I am said magpie. I just haven’t had much use for it, so whilst most people are bounding towards Pownce with their wings wide open, I’m still trying to find an excuse.

My Twitter feed is decidedly empty, having originally opened it as a way only of updating my Facebook status before I realised that was syndication for the sake of it (See integrations with BrightKite, Loopt, and Flickr integration for reference). But I do get a kick out of things like the Tower Bridge Tweets. The wonderful thing about this Web 2.0 stuff is that you don’t have to use any of it for what it was intended for (which is usually so vague and fluffy, it only really starts to take shape after the rules have been broken).

So I grabbed a copy of the Net::Twitter module for Perl and before you know it, my script that monitors if the Wifi connection on the Blakepics server had gone down was happily tweeting away with only three more lines of (my) code.

use Net::Twitter;
my $twit = Net::Twitter->new(username=>"username", password=>"password", source => "DowntimeMonitor" );
$twit->update("Internet connection ".($state ? "is now up" : "has been restarted"));