I wanted to share a small browser extension I have created and published on the Chrome Web Store called Sadhguru Quotes.

My intention is to spread the wisdom shared by Sadhguru every day by bringing it to the browser that we use most of our day.

Since the new Edge Browser is based on Chromium, the same extension can be installed on Edge (Chrome based) and Chrome itself.

Please click on the link above or here and install it on your browser.

Thank you
Vijaya Malla
@vijayamalla

In this article, I am trying to get you started with Azure Maps. How to get it set up and create the necessary resources and make changes to the Maps etc.

In my current job, we work with millions of customers who we help set up their equipment. We have a Mobile application for the field technicians and a web front application for all the other people to monitor the progress and make future planning.

Since the physical location of our customers plays a major role in planning and send out technicians for better productivity, Maps are the best bet for us. That got me started into Maps and specifically Azure Maps.

I am a .NET developer and my sample will be in  
.NET Core, Web App with MVC
and I am using VS for MAC  

Azure Maps 101

1. Create your .NET Project (on VS for MAC)

Open VS of MAC, and

1. Select App from the Web and Console
2. Selected "Web Application (Model-View-Controller)"

3. Click "Next"

   

4. I picked "No Authentication" and clicked "Next"

   

5. Give it a name and click Create

   

6. Now within a couple of seconds, the App is created and do a build on the project, you might see the following window, click "Run"

   

   

   Click on Install and Trust. Now you will the basic staring page open. Now as we have the app up and running, now let's get to Azure and create the necessary resources.

2. Create Azure Maps Resources

Open a browser and go to Azure Portal. If you don't have an account you can go for a Free Trail

1. After you log in to Azure, you will see something like below. And if you are not familiar with Azure we can group the resources on Azure within "Resource Groups". Click on "Resource Groups" on the left side.

2. Create a Resource Group

1. Pick the right Subscription from the dropdown, In Azure Subscription is the high-level container of the resources and within a Subscription, we can have a number of resource groups, which are the containers of the actual Azure Service/Resources we create.
2. Give it a Name, any name. There might be some restrictions and it will be validated as you type.
3. Select the Region where you want the resources to be created, Azure has data centers across the world and you can find more information about the regions here.
4. Click Review + Create
5. Once the Resource Group is created, navigate to that page and click on the '+' sign to add a resource.

6. In the search bar, look for Azure Maps and click Create

   

3. Create Azure Maps resource

1. Pick the Subscription
2. Pick the Resource Group, You can pick we created in the first step. (I have named mine "Learning")
3. Give it a name to your Azure Maps

4. And finally, select a pricing tier.
   There are 2 options available here

   • Standard S0
   • Standard S1

   You can click on the below link to find more information about the pricing details and the tier feature differences. Azure Maps Pricing Tier Details

5. Agree to the conditions

6. Click Create
7. Azure will now start the deployment of the resource requested and once done, You will see a button "Go to Resource", click on that to go to our Azure Maps Resource.
8. You will see something similar to the below. The brain and heart for this resource is in Azure, and the way we communicate to it is using KEYS

Click on the Authentication menu on the left and you will see important information here about how we (client) can communicate with this Azure Maps Resource.

As shown clearly there are 2 ways to Authenticate the client, we are going with the second approach, using Shared Key Authentication

Azure provides us with 2 Keys to work with and also highly recommends that we cycle through them quite often.

Copy the Primary key to clipboard

We are done here for now. Let's get back to VS and make the connection between our .NET Core Project and the Azure Maps Resource (using the Primary Key, Obviously!!)

-- Going to update --

Thank you
Vijaya Malla
@vijayamalla

The configuration I had was

and along with this, I had the 256GB SSD.

I have managed with that configuration for quite some time and now I see need to upgrade my SSD to 1TB.

To continue on my pursue, I have to first check if my current version supports an upgrade of SSD. And found out that newer versions of Macbook's support NVMe SSD's.

PLEASE CHECK THE COMPATIBILITY BEFORE GOING AHEAD WITH THE UPGRADE PROCESS

I have then researched a lot on what SSD to buy and compare speeds and minimum OS versions required etc. And finally made the purchase and started my upgrade process.

NOTE: I don't know how it works for other models, but if you have what I have then you can follow along and it worked just fine for me

Before you start to get the following ready

1. Check the compatibility of your machine for the Upgrade
2. Your Macbook Pro 15inch Retina Mid 2015
3. NVMe SSD - I got the Samsung 970 EVO Plus 1TB SSD NVMe M.2 Plus
4. Tools - I have purchased iFixit Essentials Electronic Toolkit
5. Most importantly, an adapter that connects to the SSD to the Mac SSD Port (they are not the same). I have bought this and it is good. NVMe Adapter for Macbook Pro

Let's get started.

1. Get your iFixit Toolkit ready and take the P5 pentalobe screw in hand

2. TURN OFF YOUR COMPUTER - NOT OPTIONAL
   

   Green marked screws are different from the Red marked screws. Please make a note of that. They are of different lengths.

3. UNSCREW

   

   GET YOUR SCREWS IN A SAFE PLACE. you can use the top of your toolkit

   

   THIS IS HOW IT LOOKS UNDER THE HOOD

   

   when you pull the back of your machine you will hear two clicks from the clips that the underneath has that holds the back shell.

   

   

4. Unplug your battery, use the blue tool from your toolkit to unplug.
   CANT INSIST MORE, PLEASE BE CAREFUL HERE. VERY VERY IMPORTANT STEP

   

   

5. Find the SSD, located left next to the battery plug. And get the T5 screw in hand to unscrew the SSD off the board.

   

   use your T5 screw

   

   

   

6. Get your New SSD. In my case Samsung 970 EVO Plus 1TB SSD NVMe M.2 Plus

   

7. Check out the pins of your SSD and Add the adapter

   

   

   

8. Now your new SSD pins match well with your Macbook Pro pins.

   CAREFULLY PUSH YOUR SSD INTO THE SSD PORT ON YOUR MACHINE

   

   now pins match too.

   

   screw in the SSD now AGAIN, T5 SCREW

   

9. Connect your battery now

   

   push the plug back in

   

10. Push back in the shell and put the screws back in.
    MAKE SURE OF THE DIFFERENT SIZES THAT ARE MENTIONED EARLIER

11. Turn ON the machine and HOLD the OPTION KEY.
    you will see something like this.

    

    And wait till you see the boot options window

    

    GOTCHA

    I PICKED THE "Reinstall macOS" option and end up at the following screen, unable to pick the disk destination to install the OS on.

    

    Go back to the boot options screen and pick the "Disk Utility" option to format the disk first before you install it.

    

    Give your SSD a name

    

    Format it with default options

    

    After the format is done, if you now go back to the "Reinstall macOS" option, you can see the destination disk, with the name given earlier.

    

12. Go ahead and install the new OS and have you go...

Hope you like this article and if you do please share it with your friends.

NOTE: All my links are Amazon Smile Links to an Organization I support and Volunteer. If you like the article and if you think it helped you upgrade your computer please help us by using this Amazon Smile link.

Thank you
Vijaya Malla
@vijayamalla

There comes Web Scarping.

I have started reading about it and how it can be done with Python. My general understanding is that Web Scraping is - browsing the web with software, parse the pages and get specific information that we might be interested.

How do we do it? The one library that is best out there is "BeautifulSoup".

Books To Scrape is a website that is very scrape friendly.

I have written the following WebScraping code, which can be found at my GitHub.

As any python file, first we import some libraries that are needed including "BeautifulSoup".

Import Packages

import re
import requests
from bs4 import BeautifulSoup
import pandas as pd
from tabulate import tabulate

Download the HTML and Parse

First we the get the URL to scrape, and create a BeautifulSoup object from the parsed HTML text.

start_url = 'http://books.toscrape.com/index.html'
downloaded_html = requests.get(start_url)
soup = BeautifulSoup(downloaded_html.text, "lxml")
full_list = soup.select('.side_categories ul li ul li')
regex = re.compile(r'\n[ ]*')

we now loop through all the elements in the full_list and extract the desired data

book_dict = [{}]
for element in full_list:
    link_text = element.get_text()
    link_text = regex.sub('', link_text)
    anchor_tag = element.select('a')
    fullbooklink = "http://books.toscrape.com/"+anchor_tag[0]['href']

    if (len(link_text) > 0 or len(fullbooklink) > 0):
        book_dict.append({'Category': link_text,
                      'Link': fullbooklink})

we can now save these results to a text file or to a DB. BookCategoryList is the file we open with write permissions and loop though the book dictionary and write each item to the file.

with open('BookCategoryList', 'w') as file:
    for item in book_dict:
        if (len(item) > 0):
            file.write("%s\n" % item)

You can see the sample file here Book Categories

I hope this helps.

Useful links
BeautifulSoup Documentation

Books To Scrape

Web Scraping Sample Code

Thank you
Vijaya Malla
@vijayamalla

1. To speak/blog more
2. Learn new technology
3. BE STRONG...

Wish you all great Happy New Year.

Thank You
Vijaya Malla
@vijayamalla

I followed these steps :

Step 1 : Logged into Azure Portal to check the valid pricing tier I have created a free website on Azure (TIP : With every Azure subscription we get 10 free websites) as shown below

The URL and the App Service Plan is highlighted.
Because its a free plan we don't have access to set/enable Custom Domains on this App Service. We have to Scale UP this plan to enable Custom Domain Feature

Step 2 : Scale UP Azure App service Plan

Scroll to find the following Scale Up setting under the App Service in Azure. Click on it to see more options on how we can scale up. There is an option for Custom Domains, but if you click on it, we will see message to upgrade our App Service Plan (Since, I am on the free plan)

Clicked on "Scale up (App Service Plan) " option and selected the next UP tier from Free F1 plan, which is D1 (estimated about $10/month, in my range. You can scale up more to B1 for better resource menu but higher price)

Main difference between F1 and D1 is the Custom Domains, which we want right now. I have picked D1 and "Apply" my changes. Azure Portal will show a notification on the upper right corner
and once DONE as below right under the Bell icon

Step 3 : Map Your Domain

This is where the real mapping begins. We have to add CNAME and A record entries in Azure to map the custom Domain name to the Azure website.

Under the website settings in Azure, click on "Custom Domains" and it will show more options than earlier since we have scaled up our pricing tier.

(I have make my website HTTPS Only.)

1. Click on "Add Hostname" and it will show more options to the right. Follow along and provide necessary information.

Add your hostname. In my case its "www.vijayamalla.com" and click on Validate.

2. It will show more information now, with CNAME and A-Record (Click on Hostname record type Drop down)setting that are required to be done on Azure and as well as the Domain hosting provider (in my case its GoDaddy). Below are the CNAME and A Record settings (you might see different information as per your custom domain name and azure website)

scroll down more to reveal the following changes that are required to be done at the domain hosting provider website portal (in my case its GoDaddy)

3. Update the DNS changes as shown above in GoDaddy DNS portal. Go to GoDaddy Domain Names page and click on DNS to show the settings page.

ADD or Updated a CNAME Entry for WWW Key to vijayamalla.azurewebsites.net (it will change in your case)
The Propagation takes about 30-60 min.

Add/Updated A Record and TXT DNS entry as shown earlier in Go Daddy DNS settings Page as below
The black covered part is the IP Address

Propagation might take 30-60 min

Click on "Validate" to see if the changes made in Go Daddy has been Propagated. if not try refreshing the page or try after some time. Validation takes couple more seconds than earlier as shown below.

After successful validation it is shown Green as below, Unlike earlier it was RED.

4. Now click on "Add Hostname" button in the same Validation screen.
This will add "Vijayamalla.com" to the App Service Custom Domains page.

And DONE.

Please now you can navigate to vijayamalla.com and you can see the blog. (FYI : I Used Azure pre-configured ghost blogging website).

* Only Challenge I have is the SSL is gone. Azure provides a free SSL to all the .azurewebsites.net websites. Since we are using our custom Domain, Azure SSL is not valid anymore. *

There are couple of options here.

we can either purchase a SSL cert and add it to the Azure under "Custom Domain" page, click SSL binding.

OR

Scale up Azure App service from D1 to B1 for SSL. The main difference here is that we can purchase SSL cert from Azure portal.

OR

Follow the steps here by Troy Hunt's Complete Guide To Loading Free SSL

UPDATE: I have successfully configured Cloud Flare shared SSL on my website vijayamalla.com as shown in the above mentioned blog. HUGE THANKS TO TROY HUNT

Thank you
Vijaya Malla
@vijayamalla

Exception

System.Net.Mail.SmtpFailedRecipientException HResult=0x80131500 Message=Mailbox unavailable. The server response was: 5.7.1 Unable to relay Source=System StackTrace: at System.Net.Mail.SmtpTransport.SendMail(MailAddress sender, MailAddressCollection recipients, String deliveryNotify, Boolean allowUnicode, SmtpFailedRecipientException& exception) at System.Net.Mail.SmtpClient.Send(MailMessage message) at <<NameOfMyConsoleApplication>>.Program.Main(String[] args) in C:\<<PathToMySolution>>\Program.cs:line 52

Solution

I just added the following system.net configuration to my App.Config file under the <configuration> tag

<system.net> <mailSettings> <smtp deliveryMethod="Network"> <network host="mail" defaultCredentials="true"/> </smtp> </mailSettings> </system.net>

That resolved the Exception.
Thank you
Vijaya Malla
@vijayamalla

Created a ASP.NET Web Application (.NET Framework) Project

Click "OK", we get an Empty Project

Just run the Application and we get the following, since its an empty project, we will see a 403 Http Error

Lets take a look at the references folder of the project.

Right now we only have System.Web reference and no API related references.
First lets add that (using Nuget Package manager)

Right click on References and click on "Manage Nuget Packages…"
Go to Browse tab if not selected
Search for "web api"

** side note, you can install any updates you see in Nuget Package manager if you want at this time.

Check the list of package its installing and click OK.

You may have to click "Accept" on the next screen if asked.

Nuget Package manager installs the necessary packages related to Web API. You can verify from the References folder

** Sometimes right after installing a version of a package, you may also see more updates in the package manager console. Please install them as well.

Now that we have installed the WEB API related package, we should be able to add other pieces like
1. Route config 2. Global.asax to register the route config 3. the API controller and Actions within

And then Test the API.

First lets add the RouteConfig file, which would have the Route configuration for the API, here you can set the default route settings and also add more route configurations.

To organize the code, first I have created a folder called "Startup" and then a static ".cs" file called RouteConfig.cs

Update the class contents as below.

    public static void Register(HttpConfiguration config)
    {
        config.Routes.MapHttpRoute(
            name: "DefaultApiRoute",
            routeTemplate : "api/{controller}/{id}",
            defaults : new { id = RouteParameter.Optional}
            );
    }

** you may have to add a using statement "using System.Web.Http;"

Basically what we have here is that we are registering a Route by Adding the above route to the Routes collection.

** NOTE: I have also updated the namespace as below From : namespace WebApplication2.Startup
To: namespace WebApplication2

Now that we have a route, lets add another folder for all our API Controllers called "controllers"
And add a webapi2 controller called "ValuesController.cs" as MS default api controller

Two way we can create an API Controller.

1. Creating the default template "ValuesController"

Right click on "Controllers" folder and pick the template as shown below

In the next window you can give the controller a name, make sure your name ends with "Controller". And Click "OK"

Now we have a sample template controller called "ValuesController" with sample HTTP Actions too.

2.Creating a controller and giving it any name we prefer.

Right click on "Controller" and pick as shown below

Now we have created an API SampleController but with no actions defined which we have to.

If you see the difference between the two API controllers created, the first Template one has some template code added for us but the second one is empty.

Now let us run the App and try to hit the APIs
We still get the 403 Forbidden error on the page,

since we have to hit the API endpoints, as mentioned in the RouteConfig.cs file, we have to change our URL to match the Route defined in the config file

But now we see this
404 error image.

The problem here is that, even though we have the necessary package added and the appropriate route setup, we didn’t actually initialize the routes in the application.

To do that we have to add the RouteConfig configuration to the startup of the project.
Lets fix that by adding a "Global.asax" file and add the RouteConfig configuration in there to initialize the route.

Under Application_Start method, we have to Register the Route Configuration defined in RouteConfig.cs file
** We have to add some Using statements as well.

Application_Start code as below.

    protected void Application_Start(object sender, EventArgs e)
    {
        GlobalConfiguration.Configure(RouteConfig.Register);
    }

NOTE: Add this using "using System.Web.Http;"

Now run the application and go to the API URL route and try to hit the Values Controller endpoint

** we can change the format of data the API can return and set default formats or restrict the data format etc.

DONE… That is all, only 3 steps

1. Add the WEB API Nuget Packages
2. Add the RouteConfig.cs, to define the Map Route Collection
3. Add Global.asax and Configure the Route Registration in Application_Start

Here is the GitHub Link - completed project. Not sure why you would need this, but I am just putting it out there.

Please let me know your thoughts.

Thank you
Vijaya Malla
@vijayamalla

Please check out my @VijayaMalla Gist

Thank you
Vijaya Malla
@vijayamalla

ONLY ON DEV MACHINE - DO NOT CHECK IN OR COMMIT CODE TO SERVER

ONLY FOR DEBUGGING PURPOSES

I was trying to connect to a WCF Service and got the SecurityNegotiationException and the following Exception Message

An unhandled exception of type 'System.ServiceModel.Security.SecurityNegotiationException' occurred in mscorlib.dll

Additional information: Could not establish trust relationship for the SSL/TLS secure channel with authority 'Service Name'.

Inner Exception : {"The remote certificate is invalid according to the validation procedure."}

Since I am on my local machine I didn’t have the updated Https Cert. And because of that the Negotiation between my local machine and the service is failing.

In order to resolve this issue TEMPORARILY, I have added the following code before I initialize the service, which would ignore/skip the security validation.

ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(
delegate 
{
    return true;
});

OR

ServicePointManager.ServerCertificateValidationCallback = delegate 
{
    return true;
};

I was able to successfully debug my service.

Thank You
Vijaya Malla.
@vijayamalla

To Disable this Lint Check (for CSS files), you can do the following.

Initial State TO Final Solution

Solution:

• Go to Tools Menu and then Options
• Under Text Editor (left side options), click on the black arrow next to CSS
• It should then expand to revel more options like below
• Click on CssLint, and update the "Enable CSS Lint" option to "False"
• Click on OK.
• You may have to close and re-open VS to see your changes.

Thank you
Vijaya Malla
@vijayamalla

Following the steps in the Preparation Section, Installed Docker (Community Edition) on my MAC at the Link provided. It was smooth.

Copied the dmg file to my Applications folder as asked and now I can see it running in my APP Bar on the top as below

Now I am trying to get Jenkins setup and used the command provided as below
docker run -d -p 49001:8080 -v $PWD/jenkins:/var/jenkins_home:z -t jenkins

It failed I got the following error.

docker run -d -p 49001:8080 -v $PWD/jenkins:/var/jenkins_home:z -t jenkins
Unable to find image 'jenkins:latest' locally
docker: Error response from daemon: Get https://registry-1.docker.io/v2/library/jenkins/manifests/latest: unauthorized: incorrect username or password.
See 'docker run --help'.

I thought since I don't have the Jenkins package it failed, so i ran the following command to pull Jenkins from Docker Store. (infact the previous command should pull Jenkins if docker couldn't find it; but it failed.)

docker pull jenkins
Using default tag: latest
Error response from daemon: Get https://registry-1.docker.io/v2/library/jenkins/manifests/latest: unauthorized: incorrect username or password

Still ERROR.

So finally the FIX for this is, for some reason when i login to my Docker instance on my MAC, with my EMAIL and PASSWORD it didn't work. I have to sign out and then login with my USERNAME and PASSWORD. Then it worked like a charm.

I have created a template Xamarin Forms Project (PCL) with Android and iOS projects.

Building the iOS project gave me the following error (obv: my visual studio instance is connected to my mac using the mac agent)

The root assembly /Users/vijayamalla/Library/Caches/Xamarin/mtbs/builds/iOSProjectName.iOS/ac16c487311abbbeafd486f50700030e/bin/iPhoneSimulator/Debug/iOSProjectName.exe conflicts with another assembly (/Users/vijayamalla/Library/Caches/Xamarin/mtbs/builds/iOSProjectName.iOS/ac16c487311abbbeafd486f50700030e/bin/iPhoneSimulator/Debug/iOSProjectName.exe).

I have looked around to resolve this error, trying to get my head around since I have all the latest versions of softwares installed.

I have stumbled upon this link
https://forums.xamarin.com/discussion/92773/the-root-assembly-conflicts-with-another-assembly

I have tried the solution suggested above, to make it easy I did the following steps

1. Open Xamarin.iOS.Common.After.targets file here; C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\Xamarin\iOS

2. Made a backup of this file and updated one of the files with Notepad ++ (as an administrator)

3. Made the following changes
   line 73:
   remove: <ReferencedDlls Include="@(AllBuiltProjectOutputs);" />
   remove: <Assemblies Include="@(MainAssembly);@(ReferencedDlls)" />
   add: <Assemblies Include="@(AllBuiltProjectOutputs)" />
   line 85:
   remove: < MTouchReferencePath Include="@(Assemblies)" />
   add: < !-- Don't append as an MTouchReferencePath the primary assembly itself since that's already passed as MainAssembly="$(TargetPath)" -->
   add: < MTouchReferencePath Include="@(Assemblies)"
   Condition="'%(_Assemblies.IsKeyOutput)' != 'true'" />

4. Save and now Rebuild

5. DONE

and now with the wonderful iOS Simulator on Windows from Microsoft, we can see it work just fine.

Thank you
Vijaya Malla
@vijayamalla

• Updating the Content-Type
• Changing the file extension from .xls to .xlsx

and nothing worked. I was either able to successfully export the file but with no data in it or was able to export the file with data, but when opened it would show a warning message which might upset or confuse or scare the users.
I have finally decided to use a 3rd party library and when searching for one I have found EPPLUS a codeplex link for my rescue.

You can follow the links at the Codeplex site and update your code to work for you. Following is how I used this library to resolve the problems I had with the export to excel (.xlsx) format.

Challenges:
Change the export format from .xls to .xlsx
Resolve the below warning message on open.

Export to Excel message: The file you are trying to open, ExportData.xls, is in a different format than specified by the file extension. Verify that the file is not corrupted and is from a trusted source before opening. This message should not be displayed when exporting to Excel.

Sample Data that is being sent from the JqGrid on button event (Button Click event).

"First Name\tLast Name\tTitle\tAddress\tPhone\tEmail\t\n\"Vijaya\"\t\"Malla\"\t\"Sr. Developer\"\t\"Washington DC \"\t\"(111)-222-2222\"\t\t\"sampleemail@doamin.com\"\t\n\"FirstName1\"\t\"LastName1\"\t\"Jr. Developer\"\t\"Fairfax, VA \"\t\"(222)-333-3333\"\t\t\"sampleemail1@doamin.com\"\t\n\"FirstName2\"\t\"LastName2\"\t\"Developer\"\t\"One Loudoun, VA \"\t\"(222)-333-3333\"\t\t\"sampleemail12@doamin.com\"\t\n\"FirstName3\"\t\"LastName3\"\t\"Rookie Developer\"\t\"Arlington, VA \"\t\"(222)-333-3333\"\t\t\"sampleemail13@doamin.com\"\t\n\"FirstName4\"\t\"LastName4\"\t\"CEO\"\t\"Alexandria, VA \"\t\"(222)-333-3333\"\t\t\"sampleemail14@doamin.com\"\t\n\"FirstName5\"\t\"LastName5\"\t\"CTO\"\t\"Ashburn, VA \"\t\"(222)-333-3333\"\t\t\"sampleemail15@doamin.com\"\t\n\

This is a "\t" delimited text with "\n" to separate a new line. The first set of strings are going to be the columns headings and the rest is the data for the respective columns.

One of the datatypes that the library takes is a DataTable. So it takes DataTable data and creates an Excel out of it. I have done the following to parse and convert the above data to create a DataTable.

        DataTable dt = new DataTable();
        var rows = FileData.Replace("\"", "").Split('\n');
        var columns = rows[0].Split('\t');
        for (int i = 0; i < columns.Length - 1; i++)
        {
            dt.Columns.Add(columns[i]);
        }
        for (int i = 1; i < rows.Length - 1; i++)
        {
            var dr = dt.NewRow();
            var rowData = rows[i].Split('\t');
            dr.ItemArray = rowData.Take(rowData.Length - 1).ToArray();
            dt.Rows.Add(dr);
        }

Very simple parsing, breaking the text into rows and columns. First created the columns part and then parsed each row to get the data array and created a DataRow from it and added each row to the DataTable.

Now that I have the DataTable as input to the library to create my Excel,
I have called the library specific functions to create my xlsx file.

1) I have created variables for the fileName

        var fileName = "SampleExportExcel";
        var exportfileName = HttpUtility.HtmlEncode( fileName +DateTime.Today.ToShortDateString() + ".xlsx");

2) Now that we have file name, let create the excel file.

        if (dataTable != null)
        {
            using (var excelPackage = new ExcelPackage(new MemoryStream()))
            {
                excelPackage.Workbook.Properties.Author = "Vijaya Malla";
                excelPackage.Workbook.Properties.Title = fileName;
                excelPackage.Workbook.Properties.Comments = "Export using EPPLUS library";
                excelPackage.Workbook.Worksheets.Add(fileName);

                workSheet.Cells["A1"].LoadFromDataTable(dataTable, true);

                excelPackage.Save();

                var stream = excelPackage.Stream as MemoryStream;
                Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
                Response.BinaryWrite(stream.ToArray());

                return File(stream, "application/vnd.ms-excel", exportfileName);
            }
        }
        return File(new MemoryStream(), "application/vnd.ms-excel", exportfileName);

If the dataTable is null, then it returns an empty file. Which could be corrupt (I havent tested this part)

If there is data in the dataTable, then we create the Excel file
First of all we need to create an instance of ExcelPackage, which I think is an instance of excel in memory.
Now we have to add a Workbook to the package which will contain WorkSheets.
The first 4 lines within the using is to set properties to the Excel file so that it looks complete when we have a Detail view in Windows Explorer window.

Then we need a Worksheet to host the data, so we create an instance of that within the Workbook and assign the dataTable data to it starting at the first Cell [A1].

That’s all, now we Save() the Excel Package and change the package to a MemoryStream and return it to the browser which will save it to the local machine.

This is how it looks in Windows Explorer

And on open, it doesn’t show the warning dialog window and the data is rendered as below. Success.

And this is the Worksheet name.

Now that we have this, I thought it will be good to add a header above the Columns and also BOLD the column headings as below

First I thought I have to add the header as a column to the Datatable, but that was stupid. Did some research and also added some common sense. I have move the code to add the header from DataTable creation to Excel creation part.

Added this right after the workbook properties set

                var workSheet = excelPackage.Workbook.Worksheets[1];
                var title = workSheet.Cells[1, 1, 1, dataTable.Columns.Count];
                title.Merge = true;
                title.Style.HorizontalAlignment = ExcelHorizontalAlignment.Center;
                title.Value = "Personal Information DataTable";

So basically we are just creating "title" cell, at location: Cell[1,1,1,dataTable.Columns.Count] which in English is A1:F1
And added properties to this Cell like Merge and center the text and finally the cell value.

Since we added the header and it shows up above the column header we also have to update the dataTable render to second row.

From:
workSheet.Cells["A1"].LoadFromDataTable(dataTable, true);
To:
workSheet.Cells["A2"].LoadFromDataTable(dataTable, true);

And also update the cell location

And add the following to bold the header row as below

                workSheet.Cells["A2"].LoadFromDataTable(dataTable, true);
                var columnHeaderRow = workSheet.Cells[2, 1, 2, dataTable.Columns.Count];
                columnHeaderRow.Style.Font.Bold = true;
                columnHeaderRow.Style.HorizontalAlignment = ExcelHorizontalAlignment.Center;

This would export the data as below

There are other features that EPPLUS library can do, please explore.
Happy Coding..

Thank You
Vijaya Malla.
@vijayamalla

• It can store petabytes of structured data
• supports flexible data schema
• Made for enterprise

The fact that we can store Structured data and not relational got me interested. I started reading about it online at Azure website and also several posts from Julie Lerman. One of the posts that I found interesting and informative was by Julie Lerman. And I started writing down notes, following is what I have observed from it.

Relational databases have various tables, each containing a predefined set of columns, one or more of which are typically designated as identity keys. Tables use these keys to define relationships among one another.

Azure Table storage, on the other hand, seems a bit mysterious to those of us who are so used to working with relational databases

Storing Data for Efficient Retrieval and Persistence

• By design, Azure Table services provides the potential to store enormous amounts of data, while enabling efficient access and persistence
• We just have to deal with the data and not to worry about - constraints, view, indices, relationships and stored procedures.
• Table Storage uses keys that enable efficient querying - "Partition Key"
• This key is also used for load balancing if table storage service decides to spread the data over multiple servers.
• This doesn't have a specified schema.
• It is a structured container of rows, which doesn’t care what a row actually looks like.
• We (It) can store rows with varying structures in a single table.

It All Begins with Your Domain Classes

• Traditionaly with databases we define a table, and particular structure, and specific columns and data type for each column and relationships with other tables.
• With Azure table services, we don’t design a database, but just design our classes. We define the classes and a Container (TABLE) that one or more classes belong to.Then we save those instantiated objects to store as rows.
• Imp: each class must have 3 properties that are critical in how Table service do the job.
  • PartitionKey - string
  • RowKey - string
  • TimeStamp
• Defining PartitionKey and RowKey is a challenge, to get the best balance of query and transaction efficiency. For more information you can refer to PDC09 session “Azure Tables and Queues Deep Dive”

PartitionKeys and RowKeys Drive Performance and Scalability

• The strings partitionKey and RowKey properties work as an index for the table.
• Together these properties also provide uniqueness. Act as a primary key for a row. And hence the challenge of getting the combination right.
• Each table in the entity mush have a unique PartitionKey/RowKey combination
• More than querying, ParitionKey is also used to Partition tables. Provides load balancing and scalability.

Digging Deeper into Partition Keys and Querying

• Queries to azure tables from .NET framework uses LINQ to REST.
• The context is derived from WCF Data Service (System.Data.Services.DataServiceContext).
• The BIG difference between querying ODATA (returned by WCF data services) and querying Azure table storage is that string functions are not supported.
• String.CompareTo can be used to search part of a string.

Parallel Querying for Full Table Scans

• If we were to scan through the entire table, and if it’s a large table azure can only return 1000 rows or process for 5 seconds.
• Azure returns those rows with a "continuation key" and go back to get more rows. This can be a tedious synchronous process.
• Instead : we can build the query first, by iterating through the known list of categories and build a query and then send off those queries to run in parallel.
• More design considerations for querying
  • In addition to Partition Key, Row key property defines uniqueness within a table for each row.
  • A GUID would serve the purpose but cannot help us in performing a search or sorting etc.
  • In this case we can use a combination of values. This combination of values can also help us in sorting the data, but if the application is not completely searching or sorting on those values, we can always go ahead and use a GUID in the combination.

Rethinking Relationships

• Since there is no relationships within the database tables (containers), the code is responsible, which can impact on how the queries or updates are done.
• If we were to store data across multiple tables we cannot have transacted commands, we use the Azure Table store unique capability of storing multiple rows with varying schema in a single table.
• We can use the PartitionKey to link those two or more tables within one row and use the RowKey to separate within.
  • Ex: saving contact and address info in one table, partitionKey can be common between these two but RowKey can separate those two entities within one table row.
  • This common PartitionKey ensures that the row will always stay together to take advantage of a feature called "Entity Group Transactions (EGT)".
  • This allows a single operation to carry out a transaction between multiple entities with same PartitionKey.
  • One other feature is that we can perform an update on all entities within EGT with one transaction query.

References

• Article by Julie Lerman Data Points - Microsoft Azure Table Storage – Not Your Father’s Database
• Julie's blog about all data The Data Farm
• Windows Azure Table Storage

A Big THANK YOU to Julie Lerman for all her work on all DATA. Please check out her blog mentioned above and also please follow her on Twitter.

Thank You
Vijaya Malla.
@vijayamalla