Lessons learned in sending emails to users in a complex Asp.Net MVC application using MvcMailer

There are multiple ways to handle mailing in a .net application.  System.Net.Mail is a well known assembly we often use for sending simple email messages.  I am building a fairly complex website with couple of different workflows [nothing to do with Windows Workflow] into it.  In each workflow, the website could be sending multiple emails with different text.  I wanted something maintainable and flexible.  MvcMailer is a very good open source library by SM Sohan to send mails using Razor views.  Razor Views!! yes, I am already sold on this.  It also supports other view engines btw. There is a good documentation on the gitHub and it details all the scenarios.  It is so cool and has already been on Scott Hansleman’s blog.  If you want to pass in strongly typed view then you can check this stackoverflow answer by Darin Dimitrov. Again very cool.  I like the idea of strongly typing and I have no other choice due to sheer complexity of the web application.

I wanted to share some of the lessons I learned in sending multiple emails with different content to different types of users.  Some of the things here is not related to coding but is very important in keeping yourself organized.  I tend to work backwards focusing on what the user will see.  So I first start documenting an Email Template in word document and keep adding them as new ones pop-up.  And I follow most of the steps shown below.

1. Maintain a word document with Email Templates.

This is applicable only if you are building a fairly complex MVC application with different stake holders.  It is very important to get it reviewed by different people involved in the project.  Sometimes you might get the text wrong and may be the intent is not conveyed properly to the end user.  I am not perfect at English and I like to get it reviewed by someone.  I am going to share some tidbits of such a word document. 

Template Name – Send Email to Vendors for product pickup

TemplateId – ET0001

Description

The following email will be sent to all the recipients listed below after all the products requested ready for shipping. After all the requested products are packaged, an order is considered as ready for shipping.

Recipients

1. To the shipping vendor to notify about product pickup for shipping.

Subject

Order ready for pickup

Email Body

[Shipping Vendor’s Full Name],

Your next products order has been ready for pickup and you can come on and no later than [pickup date]

Products Ordered [List Dynamically Populated]

1. Gel

2. Shaving Cream

3. Toothbrush

If you have, any questions or concerns related to your order pickup please contact [contact email address].

[Signature]

 

The purpose of this type of word document is to make sure that all the content you put in front of the user is appropriate for its intended audience. Is the wording right? Is there any misleading information? Are we conveying our intent to the user in a clear and concise manner? All these and more questions need to be ironed out before you ship this feature.  Because later down the road it will be difficult when you have say 25 or 50 different Razor Views, ViewModels sending emails. Right now my application has not reached to that level of complexity but I do see it reaching it. All the text that is underlined in the Email Body will be replaced by strongly typed ViewModel.  The Email Body will closely resemble the Razor Views in the Web Application.  Once you know the structure of all the emails you can start coding Razor Views.  So again it reviewed or proof checked by Project manager or immediate supervisor.

2. Use Strongly Typed Views

After I have my text templates ready, I can directly copy them into the web application.  I scaffold my views as necessary using the Scaffold command.  From point 1 we can create our Strongly Typed View named ET001 [TemplateId].

@using WebsiteName.ViewModels

@model OrderPickupEmailViewModel

@Model.VendorFullName,

Your next products order has been ready for pickup and you can come on and no later than @Model.PickupDeadline

Products Ordered

<ul>

@foreach (var item in @Model.Products)
{
<li>@item</li> 
}
</ul>

If you have, any questions or concerns related to your order pickup please contact @Model.ContactInfo

@Model.Signature

3. Use ViewModels to pass information to Razor Views.

After I construct my Razor Views I know what Properties I should be adding to my ViewModel.  I then create my ViewModel named OrderPickupEmailViewModel see point 2.

public class OrderPickupEmailViewModel

{

public string ToAddress {get;set;}

public string Subject {get;set;}

public string VendorFullName{get;set;}

public DateTime PickupDeadline {get;set;}

public List<string> Products {get;set;}

public string ContactInfo {get;set;}

public string Signature {get;set;}

}

4.  Modify the Interface and Class to accept your custom ViewModels

After the ViewModels are ready I go and modify the interface IUserMailer.cs methods to use my CustomViewModels. 

public interface IUserMailer
{
    MvcMailMessage OrderPickupConfirmation(OrderPickupViewModel ordp);
}

After that I modify the method inside UserMailer.cs created as a part of scaffolding.

public virtual MvcMailMessage OrderPickupConfirmation(OrderPickupViewModel ordp)
{

       ViewData = new ViewDataDictionary(ordp);
	return Populate(x =>
	{
        	x.Subject = ordp.Subject;
	     	x.ViewName = "RequestSubmissionConfirmation";
		x.To.Add(ordp.ToAddress);                });
}

Finally send the email in the respective controller.

[HttpPost]

public ActionResult SendEmail(OrderPickupViewModel model)

{

UserMailer.OrderPickupConfirmation(model).Send();

}

5. Keep common settings inside your web.config file just like MvcMailer stores smtp settings inside web.config file.  You can use web.config transforms to send emails to a redirectfolder and to end users when in production.  

If you are following any techniques or best practices to keep your self then please share in the comments below. I would like to know and get better.

How to render grouped entities using strongly typed View in Asp.NET MVC?

In this post, we are going to learn how to show grouped entities using strongly typed Asp.net MVC View, for example, show all the products by subcategories as shown in the figure below. The first column shows the SubCategories and other columns show products. Another thing to notice is SubCategory’s Name property isn't populated more than once.  The style for just that row is colored and all other rows have background color as white.

I am using AdventureWorks2012 sample database for this example. I assume you know certain basics of Asp.Net MVC applications, little bit of LINQ and EntityFramework.  I am using database first approach with EntityFramework. 

1. Create a basic Asp.net MVC4 Application. I am naming it as AspNetAjaxSamples101.  
2. Add new empty Controller named HomeController
3. Add a new ADO.NET Entity Data Model to your application.
4. Open your HomeController and add following lines to your Index method.

We are passing the View an Object of type IEnumerable<IGrouping<string,AspNetAjaxSamples101.Models.Product>>. Add a new empty view to by right clicking on the View(ProductsBySubCategories.ToList()).
Copy the following code into your Index.cshtml page. Something about the code. Our view is a strongly typed view of type IEnumerable<IGrouping<string,AspNetAjaxSamples101.Models.Product>> that you can see on the top. Next piece of the puzzle is inside the tbody tag of table. First we do a foreach loop and get the group item then we iterate through each group item i.e. Product and show product details using for loop not foreach. The reason we use for loop is we want to know which row we are rendering. If it is the first row which we determine using the if statement then render SubCategory name using item.Key.ToString(). And if it is not the first row then skip the first td cell of the row and don’t show anything. Final piece in this project is styling. In the Site.css file add following style. In Index.cshtml page, inside second for loop if the i==0 then we assign class trsubheader to the row element of the table. So there you have it.

Use Processmonitor to debug command line syntax passed through PowerShell

If you are trying to find out why a certain formatted command within PowerShell is not working then I strongly recommend using ProcessMonitor tool from SysInternals suite of tools.  When you initially fire up the ProcessMonitor then it will show you lots of information and it can be overwhelming. 

So there is a powerful filtering functionality built into the utility.  Click on the filter tab and click on filter.

Then on the filter section add two filters as shown in the figure below.

The first filter is Path is “C:\Program Files\7-zip\7z.exe” and second one is Operation is “Load Image”.  After applying the filter and running my PowerShell script I can narrow down my desired line.

So if next time any command line utility is behaving weird then debug using ProcessMonitor.

Use PowerShell variables after escaping parsing in PowerShell v3.0

Recently I answered a question on StackOverflow related to passing parameters inside a PowerShell script to command line utility 7z.exe for unzipping zip files.  In the process of debugging the issue, I tried different options and learned few tricks in working with PowerShell and debugging issues. In this post, I am going to talk about how to pass powershell variables after you use the stop parsing --% trick.

Did you knew that you can tell PowerShell to stop parsing command?
In PowerShell V3, there is a neat trick you can use to tell it to stop parsing anything after typing --%. All you have to do is use --% after your command say & 7z.exe and PowerShell will directly pass the string after the --% to the command line utility. Check out below help snippet about parsing easily found by typing PS>C:\help about_parsing

STOP PARSING:  --%
    The stop-parsing symbol (--%), introduced in Windows PowerShell 3.0,
    directs Windows PowerShell to refrain from interpreting input as
    Windows PowerShell commands or expressions. 

    When calling an executable program in Windows PowerShell, place the
    stop-parsing symbol before the program arguments. This technique is
    much easier than using escape characters to prevent misinterpretation.

So in the following example you don't have to include those parameters after --% in double or single quotes and do voodoo magic to figure out which one works.


But there is one problem with this approach, if you want to use PowerShell variables after the --% it won’t work. To solve this issue, you have to create a variable and initialize its value to --% and pass everything after it in variable(s). In the example below, I am using $stopparser variable with value --%. Finally I am passing everything using variables so PowerShell first evaluates the variables and then ignores parsing while executing the actual command. Isn't it magic.  I love PowerShell. If you know some neat trick about PowerShell then share in the comments section.

Quickly explore 159 samples of windows 8 SDK using PowerShell and touch on Surface Pro

I was looking sample source code on windows 8 and I found this collection of 159 windows 8 app samples in C#. You can also find windows 8 and 8.1 app samples in c#, vb.net, C++ and Javascript. Many windows 8 developers might be aware of it already but it becomes painful after some time to go and open each solution. However, I think most people only open a particular solution when the need arises. However, I wanted to explore all of them (159 of them), run, and see what all the different features Windows 8.1 and 8 SDK has. That way I am at least aware of the features and use them in my application whenever needed. The only problem is opening each of them through the explorer window and locate .sln file three layers deep. One more thing I am doing this all on a surface pro sitting while on a couch.

Part of my frustration with these samples was, first you have to download them samples (that’s ok), unblock them since they are downloaded from internet (fine by me), then navigate to the solution folder and open the .sln file (not good for 159 of them). There is a lot of context switching when I launch the application from Visual Studio and then the modern interface opens up another context switch. Now try to do this on a Windows 8 pro tables like the Surface Pro while sitting on your couch or lying in the bed. Too much hassle right, but I have figured out an easy way to overcome this problem.  My Answer to the problem is Powershell. I have attempted to solve this problem before(link) but it was not as elegant as this one is.
Check this powershell one-liner


I extracted windows8 samples to the folder C:\windows8samples. This one-liner first finds all the .sln files in the samples folders, then selects just the name and fullname property of the the .sln file, and then sorts them by name, and then shows you list of .sln files in a gridview window. If you are running windows 8 for viewing all the windows 8 samples, you have powershell v3. In PS v3, you can pass the object(s) you select from the gridview down to the on going pipeline. You can select a single object which what I have done here because I do not want to open multiple solutions. This is done by the –Outputmode single property. After selecting the object in the gridview interface you click ok and then I use invoke item command to open the file in the default program configured for the file.

Ok so what's simple in this as you might ask right. Copy this one-liner, create a powershell script named OpenVSSolutions.ps1, and create a shortcut on the desktop. Open the properties of the shortcut file and change the target field in the property window to this

C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe -WindowStyle Hidden -NonInteractive C:\Scripts\OpenVSSolutions.ps1



This will hide powershell window and present you gridview with all solutions and then you can select one solution and hit ok. It will open visual studio. Done. Then just run the application and explore. To ease surfing source code inside visual studio 2012 or 2013 is switch scroll to use map mode scrolling (now supported in VS2013 and productivity power tool for VS2012).

You can change icon of your script too to reflect something else than powershell icon. Mine looks like the following.

You can place the shortcut on the toolbar or pin it to start page.

Now that is simple and easy solution to browse all samples quickly using touch on a Surface Pro lying in the bed when you don’t want to sit at your desk.

This solution works for other purposes too. I have folder named C:\BadSourceCodes\ which contains ad-hoc solutions I create to quickly test a concept. Over a time the folder contains lots of solutions and finding them is also pain.  Instead I use above technique to open solutions.  I have couple of such folders with lots of Visual Studio solutions some contains samples from various books I have purchased over the years, my production source code library, badsourcecode library and others.  To make our experiment more generic lets change our one line of powershell to replace the hardcoded path with a $path variable.   Save the script file.

Now you can create multiple shortcuts for your folders and edit target property of each shortcut.
C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe -WindowStyle Hidden -NonInteractive C:\Scripts\OpenVSSolutions.ps1 “C:\BadSourceCode"

C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe -WindowStyle Hidden -NonInteractive C:\Scripts\OpenVSSolutions.ps1 “C:\Windows8Samples"

Pin different shortcuts to your taskbar and now you easily open any solution without having to navigate different folders, switch context and later forget what you were trying to do.

Bonus. Download samples of C#, Linq101 samples, windows 8 and others to create a shortcut menu like this.

This is my first attempt at creating gifs but if I click or double tap on any of the above shortcuts on my desktop then it displays a list of visual studio solutions and I can open any one of it.

Low cost method for organizing electronics components

So there is one problem you will have to deal with when you are beginning to work with electronics projects and that is organizing these tiny components like resistors, capacitors, diodes, transistors, etc.  There are different suggestions as this stackexchange question highlights. I ended by putting all these small components into tiny zip lock bags. The ones available in the grocery section of a super store will not work because they are little bit big.  I bought those pill bags found in the pharmacy section.  They look like this.

 You can put a strip of resistances say 1M ohms in one bag and use permanent marker to label it.

 Then I arranged ones with values like 10ohms, 100ohms, 150 ohms, 1k and so on in one big zip lock bag.

Yeah it is little bit hassle taking them out and putting back in.  In that case you might want to try those compartment boxes that you take along with you for fishing. They have adjustable dividers and you can put them in those.  In fact in the future that is way I am going to organize them.  I have one carry-on box with three decks in which I just dump all these zip lock bags and if I needed to carry entire box then I can do it.

New toy in the house: BealgeBone Black

Recently I purchased a new toy known as BeagleBone Black, a tiny computer worth only $45 which has Linux operating system on it just like Raspberry Pi.  This one has Linux Angstrom distribution on it but you can load Ubuntu on it if you want. BeagleBone was around for a long time and its earlier version BealgeBoard was little bit expensive but $45 is just the right price for me.

And by tiny I mean it is really very small just check out in this image in perspective below.

I also have an Arduino UNO R3 but I haven’t played with it much.  Arduino doesn’t have an operating system on it.  It is just a microcontroller but that is not the reason I haven’t played with it much.

Raspberry Pi is really very popular because of its low cost $25 and some of the cool things people are able to do with it.  For starters Raspberry Pi is really very good and for a lot of reasons. Few things I liked about Raspberry Pi compared to BeagleBone Black are: one you have two usb ports which you can use to connect a keyboard and a mouse, second to connect to an external monitor like your TV you have HDMI output and so you can directly plug into your TV without requiring any external adapter (assuming you have an HDMI cable) and third some of the boards that are available for Raspberry PI. In BeagleBone Black you only have one USB port so you will need a USB hub to plug in a keyboard and a mouse, plus it uses a micro HDMI port so you use some kind of adapter again to hook up to your TV or just buy one of these.  For a full comparison you look this post and this comparing Raspberry Pi, BealgeBone Black and Arduino.

BeagleBone is rock solid in terms of no of I/Os (65) you have available. So if you are interested in robotics applications which require lots of I/O pins then BeagleBone Black is the board you want. And that was my primary motivation to buy BeagleBone Black. Check out expansion connectors section in the image below.

It has Arduino style programming library, and by that I mean you can turn a particular pin High and Low just like you would do in Arduino but in JavaScript.  Did I just said JavaScript?  Yes you heard it right, it does all this magic using JavaScript.  So BeagleBone Black has python, node.js (Ah! I like it) and Cloud9 IDE along with Angstrom Linux distribution.  You can program using either python, node.js or plain C. I chose node.js.  There is BoneScript, a JavaScript file which does all the magic to turn a pin High or Low on BeagleBone Black. I will go into basics of programming BealgeBone in next couple of blog posts where I show you my little experiment with BealgeBone Black.  BBB uses 5V power supply and you can use USB cable to power it.  If you are interfacing multiple sensors then I recommend using an external power supply.  Typical voltage on the I/O pins of BealgeBone has 3.3 volts.  Once you plug BBB into your computer then getting started is really easy.  This link has all the details but just visit http://192.168.7.2 and you are in business in your browser (don’t use IE).

I had a spare old Sony Vaio sitting around which I wasn't using anymore so I loaded Ubuntu on it to play with BBB.  It is really very cool once you figure out the basics.   Below are few things I learned on the way to playing with Linux and electronics.

1. Electronics: Research first about what you are buying.  There are components that you will end up buying that you might not need or they might not be of different specifications. Ask somebody on the forums and there are really awesome people hanging out in these forums who will help you with it.

2. Don't update operating system on BeagleBone Black before checking what it does for you.  I tried updating OS and it blew up on me and I had to reload using a 4GB microSD card.  So another tip is keep one microSD card handy.  You will need it.

3. Learn some quick Linux OS commands to work in the terminal.  Being able to navigate into the OS will help you are lot.

4. Create a plan, sketch it out and make a list of components you will be needing to complete a project.  So this one I learned it the hard way. If you don't make a list of components and you start playing around and when you think you will need something then you will end up making multiple trips to RadioShack paying more or end up waiting for components to arrive in the mail.  And waiting for stuff is really annoying because you are so excited to hack into different project but you can't until it comes.

5. Buying the board is not the only thing you will do in an electronics project.  You will need a soldering iron, wires, resistors, transistors, de-soldering wire, multimeter, capacitors, leds, batteries, breadboard, boards and sensors.  So have some budget and buy everything at once so you don't end up wasting time and money buying them separately.

6. Safety: This has to be number one thing but please be careful with electronics and understand what you are doing. If you are young then have your parents by your side or someone who knows what you are doing.     Be safe and if you aren't not sure then please ask.

Electronics is a lot fun and don't get intimidated by it.  I have a bachelors degree in electronics and communication but trust me I am just like any new person trying to learn it first time.  I didn't liked electronics initially and was turned away by it because the way I was introduced to some of the concepts in electronics by the education system.  However, six years later I am digging deeper into the open web and YouTube to discover my lost passion into electronics once again. So don't give up.  Play with it.  If you get stuck then just ask somebody in person or on online forums, read online, watch YouTube videos and play again.