Yesterday on Leon's Blog, secretGeek, I noticed they had released v3.4 of TimeSnapper. One of the features that caught my eye was the ability to develop/add plugins to it.

I love plugins, I've written plugins for Windows Live Writer, Outlook, dasBlog, and more.  Everything should have an SDK or plugin'able architecture. I championed it at work and we were one of the first Archiving Vendors with a 'real' SDK (I've built demo Vista Gadgets, integration scripts, federated search providers and PowerShell commandlets for it).

Anyway, the TimeSnapper plugin model looked really clean and easy to use. Read the one page description and your ready to go (didn't even download the sample code - it was so clear how things worked there was no need).

I wanted a little play around with it, so I though upload a snapshot to TwitPic would be a good idea. Opening a new project in Visual Studio, adding a reference to the ITimeSnapperPlugin.dll, create a new inherited class from ITimeSnapperPlugin and implement the interface :

    #region ITimeSnapperPlugin Members

    bool ITimeSnapperPlugin.Configurable
    {
        get { return true; }
    }

    void ITimeSnapperPlugin.Configure()
    {
        System.Windows.Forms.Form frm = new TwitPicPluginConfig();
        frm.ShowDialog();
    }

    string ITimeSnapperPlugin.Description
    {
        get { return "Uploads snapshots to TwitPic"; }
    }

    string ITimeSnapperPlugin.FriendlyName
    {
        get { return "TwitPic Plugin"; }
    }

    object ITimeSnapperPlugin.HandleEvent(TimeSnapperEvent TimeSnapperEvent, EventArgs args)
    {
        switch (TimeSnapperEvent)
        {
            case TimeSnapperEvent.SnapshotSaved :
                // upload it it to TwitPic
                if (IsTimeToUpload())
                {
                    string fileName = ((TimeSnapperPluginAPI.SnapshotSavedEventArgs)(args)).Activity.Filename;
                    Debug.WriteLine("Uploading " + fileName + " to TwitPic");
                    XmlDocument xmlDoc = UploadToTwitPic(fileName);
                }
                break;

            default :
                Debug.Assert(false, "Should never occur");
                break;
        }
        return null;
    }

    TimeSnapperMenuItem[] ITimeSnapperPlugin.MenuItems()
    {
        return null;
    }

    Guid ITimeSnapperPlugin.PluginID
    {
        get { return new Guid("50744334-C5A0-44f1-BE64-5BBF32FDA79D"); }
    }

    TimeSnapperEvent[] ITimeSnapperPlugin.SubscribesTo()
    {
        return new TimeSnapperEvent[] { TimeSnapperEvent.SnapshotSaved };
    }

All that was required was to give it a new Guid and name/description and then subscribe to the 'SnapShotSaved' event and handle the event when it was triggered.
To get the image uploaded to TwitPic I used some code from the excellent Yedda Twitter C# Library (just the stuff for posting image data to a url).
That all worked a breeze, but it was sending images (and posting to my twitter account) every 10 seconds (and of course it was hard coded to my username/password) - what was needed was a bit of configuration...

Luckily the plugin model provides an excellent and easy way to do this (set the Configurable property to true, and handle the Configure event). A bit more jiggery pokery, one modal dialog and an XML config file later, it was all working (configurable username, password, twitter message and frequency of updates) - although I really should do something better than store the username/password in clear text in an XML file...

If you want the plugin, just drop this dll into your %install%\plugins folder and restart TimeSnapper.

Apparently I am rapidly becoming 'Geo Guy'. I seem to be adding Geo / Gps support and plug-ins to everything I use...

I just finished adding 'Insert GPS Link' support to PockeTwit (a great little Windows Mobile twitter client - really, go and get a copy now...)
Previously I added GeoRSS support to dasBlog for individual blog posts as well as the RSS feed, and I also added geo microformat support to Windows Live Writer with my 'InsertGeoMicroformat' plugin.

So, what's next - have you got an app that needs Geo / GPS support added ?

  I've been toying around with creating an Outlook addin recently that adds a new panel to the main Outlook inspector window. Actually it is going to be a 'folding' or 'collapsing' windows similar to the docked ToolWindows in Visual Studio.

Anyway, the stuff around getting the correct window handle for the Outlook inspector window and resizing it to allow some space to insert my new panel was fairly simple, but I also had to hook into the message look of the window so that I could capture any move or resize messages and so resize things again to accommodate my panel.

I had started developing it as an Outlook add-in but to speed things up (and prevent me having to register / unregister the addin between tests etc I decided to develop it as a separate app- I could still hook into Outlook and move things around.

The problem came when I was trying to hook the inspector window message loop - it didn't seem to work. I fired up Spy++ and check that the inspector window was getting the messages - which it was - but they were never getting delivered to my hook code.

I was using System.Windows.Form.NativeWindow and overriding the WndProc function (see my NativeWindowListener class below). To get the hook in place I was creating a new NativeWindowListener class with the inspector window handle as the parameter. Checking the handles and the delegates etc it all seemed to be correct, I just couldn't fathom why it wasn't getting any of the messages.

Then the penny dropped. Outlook is in a separate process... (NativeWindow only works across the current process and window handles that are contained in it). What would be needed in this case is a system wide hook, that requires use of the Win32API and interop. I reckon this is overkill just to save a bit of development pain, so will probably move to something where the Outlook addin dynamically loads the panel in and make something available to have the add-in reload the panel - this should allow me to develop the panel code (the majority of the app) without worrying to much about the Outlook addin side of things.

using System;
using System.Windows.Forms;
using System.Text;

namespace Outlook_Subclasser
{
[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")]
internal class NativeWindowListener : NativeWindow
{

    // Constant value was found in the "windows.h" header file.
    private const int WM_SIZE = 0x0005;

    public NativeWindowListener(IntPtr handle)
    {
        AssignHandle(handle);
    }

    [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")]
    protected override void WndProc(ref Message msg)
    {
        switch (msg.Msg)
        {
            case WM_SIZE:
                // do your processing in here
                break;

            default:
                break;
        }
        base.WndProc(ref msg);
    }
}
}

and then to use the class you would find the handle of the window you want to subclass and create a new NativeWindowsListener passing in that handle to the constructor. Note - this does not cover a number of aspects around releasing handles etc - you will want to make sure these are covered off...

MyForm myForm = new MyForm();
NativeWindowListener nwl = new NativeWindowListener(myForm.Handle);

GEO 51.4043197631836:-1.28760504722595

I've had a lot of interest in my SMS Gateway app since this post. SMS gateway consist of two components :

SMS Gateway Addin
This is an Outlook addin that adds a new toolbar to your Outlook instance. The toolbar allow the user to choose a mobile / cellphone number (from their contacts) and enter a message. When they hit the enter key after the message (or click 'Send') a new Task is created when has a subject of 'SECRETCODE' and the mobile / cellphone number and the details being the text of the message.

At some stage this Outlook Task is synchronized (over ActiveSync / Direct Push) to a Windows mobile device...

SMSGateway
This is a small app running on a Windows Mobile device that every 15 seconds checks through the tasks. If it finds any tasks that have a subject beginning with SECRETCODE then it parses out the mobile / cellphone number and sends the message text (from the Task details) to that mobile / cellphone number via SMS. Note: the SECRETCODE word is configurable.

Why develop this ?
The purpose of this app was really to allow me to send SMS messages easily from Outlook without having to sign up for (and pay for) a web to SMS service (I already get 100's of free SMS messages with my mobile / cellphone package).

The application is free for anyone to use (drop me a line - in the comments - if you do use it...)

Windows Mobile CAB file (copy the file to your Windows Mobile device and click on it) : SMSGatewayMobile.CAB
Setup file for the Outlook 2003 Add-in (Outlook 2007 coming soon) : SMSGatewayAddin2003.msi
Source for both the applications : SMSGateway.zip (includes test Outlook 2007 addin code)

I'd be really interested to hear from anyone using this.... post in the comments...

Programmatically sending an SMS message from your Windows Mobile is fairly simple these days.

You'll need the WM6 SDK. Start a new Visual Studio 'Smart Device Project', add a reference to Microsoft.Windows.PocketOutlook, then use the following code...

using Microsoft.WindowsMobile.PocketOutlook;

public void Send(string to, string msg)
{
    if ((to != string.Empty) && (msg != string.Empty))
    {
        SmsMessage message = new SmsMessage(to, msg);
        try
        {
            message.Send();
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.ToString());
        }
    }
}

Job done...

Recently I have wanted to be able to send SMS messages to my contacts without having to pick up my phone and mess around with the mini keyboard (I wanted to do it directly from PC, but have the message still send by the phone...

There are solutions around that allow you to send a SMS from a form on a web page, but these are generally paid for services or limited to XX messages per day - I have a mobile contract with unlimited texting, so why would I want to pay for another service, and I didn't want to be limited in the volume of texts I can send per day. there are also solutions around that require the device to be docked / plugged into the PC, I didn't like this either as it's just too much hassle (and therefore I never do it)...

So I came up with a simple but effective solution that makes use of ActiveSync / push email technology that is built into Windows Mobile devices.

Basically I wrote an Outlook Addin that allows me to choose a contact from a drop down list, type in the message and "send" it - when I say "send" it, what I mean is the request is transferred to the WM6 device which then sends the actual SMS message.

So it goes like this :-

• User chooses the contact from a  drop down list of all contacts with mobile numbers.
• User enters the text of the message
• User clicks send
• Outlook Addin creates a new task with a secret keyword followed by the mobile number as the subject and the message in the body of the task.
• (after a few seconds) the new task is synchronized to the WM6 device via push email / ActiveSync
• WM6 device regularly checks the tasks list for a task with a subject that starts with the secret keyword 
• The subject line is parsed to get the mobile number the text is to be sent to
• The body is parsed to get the text of the message
• A SMS message is send from the WM6 device.
• The new task is deleted (or marked as complete)
• The change to the task (delete or marked as complete) is synchronized back to the PC via ActiveSync / push email.

I'll have more details, the installers and all the source code available next week...

UPDATE: See the follow up to this article here which includes binary files and full source code.

Originally I had my website set up to default to my blog (so dasBlog was installed at the website root level instead of in a /blog subfolder).

Recently I have been writing some Web Applications and wanted to restructure my website so that there is a subfolder for each app / main area (blog, projects, etc).

The problem being that all the links out there point to http://www.kapie.com/blog/somefile.aspx and these would all be dead link when moved to http://www.kapie.com/blog/somefile.aspx, so I needed to respond with a HTTP 302 to the original links and tell the client that it should temporarily redirect to the new location (changing to a HTTP 301 when I am happy that it is all working).

This called for a HttpModule...

namespace KSL
{
     public class BlogRedirector : IHttpModule
     {
         private EventHandler onBeginRequest; 

         public BlogRedirector()
         {
             onBeginRequest = new EventHandler(this.HandleBeginRequest);
         }
 
         void IHttpModule.Dispose()
         {
         }
 
         void IHttpModule.Init(HttpApplication context)
         {
             context.BeginRequest += onBeginRequest;
         }

         private void HandleBeginRequest( object sender, EventArgs evargs )
         {
             HttpApplication app = sender as HttpApplication;
 
             if ( app != null )
             {
                 HttpContext context = app.Context;
                 string host = app.Request.Url.Host;
                 string requestUrl = app.Request.Url.PathAndQuery;

                 if (requestUrl.Contains(@"/blog/") 
                     || requestUrl.Contains(@"/foo1/") 
                     || requestUrl.Contains(@"/foo2/") 
                     || requestUrl.Contains(@"/foo3/")
                     || requestUrl.Contains(@"/foo4/")
                     || (requestUrl.ToLower() == app.Request.Url.Scheme + @"://" + host + @"/default.aspx"))
                 {
                     return;
                 }
                 else
                 {
                     Uri newURL = new Uri(app.Request.Url.Scheme + @"://" + host + @"/blog" + requestUrl);
                     context.Response.RedirectLocation = newURL.ToString();
                     context.Response.StatusCode = 302;
                     context.Response.End();
                     return;
                 }
             }
         }
    }
}

This basically allows me to redirect any url that does not contain /blog/ or /foo*/ or is not /default.aspx by sending a 302 status code and adding /blog/ to the url to generate the redirect url. The compiled DLLs were stored in the bin folder off the root and the web.config in the root needed the following adding...

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
  <system.web>
    <httpModules>
      <add type="KSL.BlogRedirector,BlogRedirector" name="BlogRedirector" />
    </httpModules>
  </system.web>
</configuration>

This seemed to work fine some of the time, but was a bit hit and miss.... Further investigation pointed me at the web.config files in the subfolders and that they would inherit the sections from the root web.config. So all the subfolder web.config files got the following added.

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
  <system.web>
    <httpModules>
      <remove name="BlogRedirector" />
    </httpModules>
  </system.web>
</configuration>

I have just completed a new Windows Live Writer plugin. This extension allows ease insertion of geo microformat information.

It allows the user to easily choose the location they want to insert (in microformat) from a Virtual Earth map and also configure how it is displayed (if at all on the post.

Recently I (with considerable help from Alexander Groß) added GeoRss support for dasBlog. The co-ordinates can be specified when adding a post via the web interface. This plugin is stage two of this support, stage three will be parsing the geo microformat when a post is added and using that to populate the GeoRss info.

The end goal being to allow the geo info to be entered when creating a post in Writer and having that info available in GeoRss format in the feed.

I started this plugin with the view to using Google Maps, however they require that you get an API key and that key is only valid for a particular web site / URL path. This foiled my plans to embed the map in a Windows Forms WebBrowser control (I did look at producing an html page that was served from my web site, and using it embedded in the WebBrowser - not scaleable and too much configuration for a normal user to do.

I hadn't looked in depth at Virtual Earth, but recently went to MixUK:07 and saw a couple of demos / presentations on it - a quick look found that it didn't need a API and was not tied to a particular URL / path - the JavaScript for it is pretty similar to the one for Google Maps so learning curve was pretty short. The only issue I have with http://local.live.com is that there is no (currently) facility to enter a GeoRss feed in the search query and just display the data (the current method of displaying this kind of data is to embed a map in your own pages and use their API to display the items as a 'collection').

You can get the installer for it here InsertGeoFormatSetup.msi (325Kb).

Some of the code I have for importing data (from ACT! 2000) to MS CRM creates new 'PhoneCall' activities / objects. The problem is, that it seems MSCRM does not allow you to programmatically modify the 'create date'.

Here is the code I use...

phonecall pc

            CrmDateTime start = new CrmDateTime();

            start.Value = DateTime.Parse("10/08/2005 12:30");

            pc.actualstart = start;

            pc.scheduledstart = start;

            CrmDateTime end = new CrmDateTime();

            end.Value = DateTime.Parse("10/08/2005 14:30");

            pc.actualend = end;

            pc.scheduledend = end;

            pc.subject = "Phone call regarding sales of Widgets Q2/2005");
***

            string desc =  "Start    : " + pc.actualstart.Value + "\n";

            desc += "End       : " + pc.actualstart.Value + "\n\n";
***

            desc += "The details of the phone call go in here");

            pc.description = desc;

            pc.regardingobjectid = new Lookup();

            pc.regardingobjectid.type = EntityName.contact.ToString();

            Guid contactGuid = new Guid(guidOfContactWeTelephoned);

            pc.regardingobjectid.Value = contactGuid;

The actualstart and scheduledstart (and ends) get populated with the current datetime (this seems to happen if the time they are set to is in the past).

Note the two lines between the ***'s - this is my solution / workaround and simply include the start/end times as text in the body/description of the phone call object.

A few months ago I added a 'Daily Report Email' feature to dasBlog, so I could have the activity reports (referrers, searches etc) delivered to my mailbox at the end of every day.
I wanted to take this one step further and deliver it via RSS (and dasBlog is a RSS engine after all).

There were a couple of suggested methods raised on the dasBlog developers mailing list; one was using HTTP authentication - I was reluctant to use this as Outlook 2007 does not support authorized feeds. The other suggestion was to obfuscate the URL with a Guid or the like - this was my preferred option.

So, I have been working on it over the past few evenings, got it rolled out to this blog and it seems to be working pretty well.

I added a checkbox to the site configuration page, that when checked generates a Guid that is used as part of the path. The 'activityrss.ashx' page doesn't exist at that path (in fact it doesn't exist at all!), instead there is a HttpHandler for the file 'activityrss.ashx' that intercepts any requests for that file and does some processing.

In this processing I check that the requested URL contains the Guid and if so, generate the Activity RSS feed. The content of each feed item is the activity report (similar format to the daily report email).

NOTE: This is not in a release yet, if you want it you'll have to check out the source, patch it with this patch file and compile, deploy it manually.

So after some poor experiences with the MSCRM Data Migration framework I decided to get pragmatic and write a C# app to do the migration.

The CDF is poorly documented at best, it seems they (Microsoft) give you a bunch of database tables, an Excel spreadsheet outlining the schema and a 'Good Luck'. There is little 'googleable' (is that a word) knowledge about it either.

The good news was that the MSCRM SDK is much better documented (on MSDN). There is not a lot of googleable info around but there is enough (Stunnware proved pretty helpful for me).

There were other challenges also - the software we purchased for exporting the ACT! 2000 data to Access (Exporter Pro) did a good job of getting the data out of ACT but the Unique ID left a bit to be desired, they are basically a munge of punctuation characters and alphanumerics - what's wrong with a GUID or a int ??

So, anyway, I got there in the end...

The connecting to the CrmService was pretty easy, as was the population and addition of an account.

I'm in Western Mass (Westboro, MA) again this week and while that normally means 16 hour days (there is nothing much else to do but sit around a hotel room so why not...), this week I decided to work on a personal project for a bit.

Part of it was some code to check a machines public IP address and update it to DynDNS. Luckily they have an excellent developers / API section that explains everything you need to do this. There are two sections to it, detecting the machines public IP address and updating the hostnames associated with your account, both of which they provide a service for.

It's pretty easy to follow and within an hour or so I had come up with a class to do both tasks. Here is a snippet for the 'CheckIP' function:

Just call a URL (http://checkip.dyndns.com) and it returns your public IP address, there was some parsing of the return text but it is pretty simple. Click the link and see for yourself.

Next was the 'UpdateIP' function, here's the snippet:

It is basically just a case of passing a querystring with all the details to http://members.dyndns.org/nic/update , ensuring you set the credentials to your DynDNS account username and password and specifying a unique User-Agent.

The complete project files (including a small 'user' application to test it) can be found here (61K).

Just didn't work for me.

I had it all set up as per the docs, imported the data into the CDF database, tried to 'Migrate' and it completed but migrated no records (even though I had 8000+ in the CDF tables).

I tried both the snippets I gleaned from googling :

• Make user the user does not have 'Restricted Access'
• Turn off 'Fast Load' mode.

Still no joy. All the 'required' fields are populated, the mapping wizard works correctly, but no 'migration'. It is a real pain as there is nowhere to go next, the documentation about CDF is really poor as is the logging/trace/error output from the Migration Wizard.

Ever the pragmatist, I cracked open VS and and have started on an app which uses the CrmService webservice to import the data. Watch this space for the source when I'm done...

One of the projects I am involved with at work was evaluating Microsoft CRM (MSCRM).

Out of the box, it comes as a pretty well fully featured CRM application, but it is also hugely customizable. I downloaded the SDK from here and had a quick play.
Within 20 – 30 minutes I had a quick extension / customisation working – it is a simple webpage allowing customers to register their own details and when submitted, that customer is automatically added to MSCRM.

It was incredibly simple to get working, just :-

• Create a new web project
• Add a web reference to MsCrmSdk
• Add some textboxes and a submit button and on the 'submit click' event just :-
  • Create a new CrmService object
  • Set the URL for it and provide credentials if necessary
  • Create a new contact object
  • Populate it with the data from the textboxes
  • Call 'Create' on the CrmService object passing the contact object as a parameter

You're done...

Below is some sample code – it only picks up a few details about the contact, but should be fairly easy to enhance ... Enjoy

 I use dasBlog as the vehicle/technology for this site and currently have it configured at the root of the website (so you go to http://www.kapie.com/blog and you get directly into this blog). This is kind of an unusual setup as most people put it in a /blog subdirectory or virtual directory.

I have plans to put a fair bit more static content up so I wanted to change to the standard of /blog subfolder - the problem is that all my current links will fail when I move the content along with all the content google has cached / indexed about the site - Not Good.

Scott Hanselman suggested in response to a question I posed on the dasBlog mailing list that writing a HttpModule with a HTTP temporary redirect (HTTP response code 302) might be the way to go and reckoned it might only be a handful of lines of code....

 I was pleasantly surprised at how easy it was...

I have included the code below in case anyone else might find it useful. It is pretty specific at the moment (takes the requested URL and if it does not include /blog/ then it insert it) but it could easily by made generic (RegEx or the like).

Happy to share the actual source files if anyone wants them - drop me a mail/comment. 

In the first version of my GPS Library software (written in VB6) I had a 'Protocol' property that indicated which protocol we were using (for example Garmin, Magellan, NMEA etc). Then, every time we needed to do something at the protocol layer (Sending or Receiving data) we had an if statement :

If gps.Protocol = GpsProtocol.Garmin Then
     ' Do it this way
EsleIf gps.Protocol = GpsProtocol.Magellan Then
     ' Do it that way
Else
     ' Do it the other way

Horrible and messy !! Adding a new protocol meant going back to every function and amending it.

In the new .NET version, it's much more object oriented and I've used a number of software design patterns.

To solve the above problem I used a Factory pattern. The Factory pattern allows you to create objects but let the client decide what type those objects should be. So, I can basically let the client set the Protocol property and then, depending on that setting create a different object for each protocol.

I start with a base class that all the 'codec' classes inherit from, then in the 'creation' (when the client creates the object) I look at the Protocol property and choose which concrete class to return:

GpsCodec is the base class and the concrete classes are GarminCodec, MagellanCodec etc. I have a static method in the base class called 'CreateCodec' that takes a 'Protocol' parameter. So it looks like this

public static GpsCodec CreateCodec(GpsProtocol protocol)
{
     switch (protocol)
     {
          case GpsProtocol.Garmin:
               return new GarminCodec();
               break;
          case GpsProtocol.Magellan:
               return new MagellanCodec();
               break;
          default:
               return null; // error
               break;
     }
}

So now I can simply create a codec class based on the Protocol property and use that for all the communication to / from the device. Adding a new protocol is simply a case of creating the new class and modifying the CreateCodec method - much simpler.

Watch this space for the free .NET GPS Library (including source).

About 4 or 5 years ago I wrote a GPS ActiveX control in VB6.0.
Although it work really well (and fast), it was difficult to maintain - to be honest it was pretty messy, a large monolith with some real horrible 283654276354 line functions.
I sold it as Kapie Systems for a while and had some good success with it, it was mentioned at a couple of GIS conferences etc...

Anyway, I had been meaning to update it (to .NET) for sometime, but I wanted to do it right, make it easy to extend (to plug-in other GPS protocols) and easy to maintain.

I just got a basic .NET implementation of it working last night (at last !!). It's Garmin propriety protocol only at the moment, but the whole framework is there for extending to other protocols (which I'll be adding shortly).
I also added import and export to GPX format, which is a great portable standard - the GIS / Mapping community has been crying out for this for ages.

I expect to have something releasable in a few weeks (it will be open source) but if anyone wants an early view or wants to discuss my plans ideas then let me know.

One of my gripes with dasBlog is the reporting. To get to reports I have to browse to my blog, login and then view the reports online - bit of a pain doing this every day (yes I am so vain that I like to see my stats on a daily basis).

So I spent a few hours recently adding an 'Daily Activity Report' feature.  It was surprising easy - checkout (get a working copy) of the source from sourceforge (browse it here https://svn.sourceforge.net:443/svnroot/dasblogce/trunk), familiarize yourself with it, add your changes and create a patch. Send the patch to someone with admin rights (so it can be checked in) and that's it... I'd recommend to anyone to try it out...

Anyway the 'Daily Activity Report' feature - basically starts a background thread which caches the current date and then ticks every hour. Each tick it will check the current date against the cached date and if they do not match then it will send an email to either the Notification list or the Site Owner / Administrator. It is configured by simply checking a box in the configuration page (in the SMTP Server section)

The email contains similar detail to that of the 'Activity... Referrers' page.

I also made the method / class that implements the creating / sending the report public so that it can be extended - I was thinking along the lines of a 'Send Daily Activity Report Now' button or enhancing the Mail-To-Weblog to monitor for a specific phrase in the subject and if found to send the report (maybe also specify the date)...

Watch this space for updates...

Singleton Design Pattern, is a solution to a common problem in the software domain where you want to create ONE AND ONLY ONE instance of an object/class.

Put simply, it stops client applications creating their own instances of an object and routes all creation of the object through one method. If an instance of the class already exists then that instance is returned, if an instance of the class does not exist then a new instance is created.

So, no matter how many clients access the class there is only ever one instance (that all clients access)

Here's some sample code of how to achieve a Singleton class :

So to clients would simply use it like this

Any subsequent clients who make the same call get a reference to the already created instance of the class.

Here's the code for the macros I created - feel free to copy / compile it yourself. I also included a compiled DLL here - BUT it is compiled against .NET2.0 so will only work if your hosting Dasblog in a ASP.NET2.0 virtual directory.

• Copy the compiled DLL into your /bin folder
• Edit your Web.config file, locate the <newtelligence.DasBlog.Macros> node
• Add the following element <add macro="khmacros" type="KensDasblogMacros.KensMacros, KensMacros"/>
• Edit your template pages to include <%TrackbackCount()|khmacros%> or <%TrackbackountAll()|khmacros%> or <%KensBlogStats()|khmacros%>

So, having recently updated this website to Dasblog 1.9, I decided it was time to check out the source and have a play around.

The initial easy step to get involved seemed to be writing some Macros (I wanted to extend the default blogStats() macro to include Total Trackbacks and also add a Trackback Count to each post item in the footer.

There is a great intro to Creating Dasblog Macros on their Documentation Site, also googling for Dasblog macros uncovered a few good sites

Anyway, I cracked open VS and spent a couple of hours writing some new macros, compiled them, made the requisite changes to my homeTemplate and itemTemplate but they just seemed to be return null strings. Checking the (Dasblog) event log showed that it was failing the find the Type for my Macros.

I checked and rechecked everything and was convinced that everything was as it should be. Stumped!!
Viewed my DLL in reflector, typenames were all correct - what was I doing wrong ??

A quick post to the Dasblog developers mailing list resulted in someone suggesting that I check if I was running a .NET2 compiled DLL in a .Net1.1 IIS virtual directory - Doh !!

Updated the virtual directory to ASP.NET 2.0 (easier than reverting to VS2003 from VS2005), 'touched' the web.config, refreshed the page and 'ta da...'

Changes and source code to be rolled out to this web site in the next day or so (more testing to do on how ASP.NET 2.0 works out),

Quick update on the TaHoGen open source project...

I just tidied up the whole source tree, added all the projects in a logical layout to one solution. I also sorted out the Visual Studio addin with better error handling and added a Setup project so that it can be easily installed by an end user.

Murad's excellent SchemaBrowser was added added and checked in, now allowing us to glean data from databases to use in the code generation. We're closing in on CodeSmith...

Next step is to demonstrate use by including a number of templates.

The problem with the addin (that was so difficult to remedy) was MDA's - difficult to troubleshoot and even more difficult to fix.

When the addin is called by VS it tries to save a reference to the instance of VS that is creating it - this is so we can get a handle on the OutputWindow and add some new panes to it.

These sometimes (intermittently) get blocked by MDA's and the panes do not get created - the panes only show build output text so I added some error handling to continue processing even if we cannot write to the pane.

Anyway, if you want to take it for a test run, you can get it here.

So I tidied it up a bit, added error handling and added a deployment project. Zip files are here :-

Windows Installer (msi) in a zip file

C# Source Code

Enjoy...

Having raved about WindowsLive Writer recently,  I've been using it extensively over the past few days.

I'm using Dasblog 1.8 for this site and apparently it doesn't support the API required to automatically upload images etc (Writer recognizes this and offers me FTP instead - which works well). That's all fine and good for images, but sometimes I want to give links to files...

Writer provides a pretty easy API and plug in architecture so I thought I'd write my own Plugin which allows the user to browse for a file, upload it and insert a link to the file into the post content.

This was a really exercise, taking only about 2 hours total for coding and testing. You can get the binary files here and the source code here. This was really for my own use (and doesn't do any error handling), but feel free to use it...

Basically, copy the binary files to the Plugins sub folder of your Writer folder and restart Writer, it should be automatically recognized and you'll get a new item in the 'Insert' tab of the sidebar

Click on the item and you get a dialog allowing you to specify the file to upload, which site to upload it to and the text to display as the link in the post.

The XML file allows you to specify what sites you want to upload to. Specify the correct settings for your FTP server / path.
Only one item should have 'default' set to true (this makes it the default selected item in the ComboBox) and if you have 'debug' set to true then you will get a messagebox indicating the Uri it is trying to send the file to.

So I've spent a lot of time (seems like a huge amount) trying to get to grips with the XMLSerializer in .NET. I think I have pretty much come to the conclusion that what I'm trying to achieve is not possible (even though it seems like a logical thing)...

I'm trying to serialize a bunch of class data into XML format. The actual objects seem to Serialize correctly (if I set the ArrayList, al, to public in the collection) and I can modify the element names in the XML that is produced by using the [XmlElement("new_name")] attribute.

However, trying to set the ArrayList to non public and have the XMLSerializer use the C# indexer to get the objects gives me no end of hassle.

1. If I set the indexer to return objects of the interface type it will always fail
2. If I change the indexer to return objects of the concrete class then I cannot seem to modify the element name of the concrete class in the XML - it always comes out as 'MyClass'

Looks like it's going to have to be implementing IXMLSerializer instead...

Here's a snippet of the code that I can't get working...

I got hold of Philip Laureano and we've been discussing the best way to make this available publically (we'll probably lump for Sourceforge).

Interestingly he also mentioned that someone else has written a 'SchemaBrowser' style extension for it - giving the whole application much more power (on a par with Codesmith).

I rewrote the VS2005 addin so that instead of the UI being a 'non integrated' Windows Form, it is now embedded in a VS IDE ToolWindow. Some screenshots below...

	Expect to see details of the sourceforge project name and possibly a CodeProject article from Philip soon...

Blank entry, simply to list out the categories.