Burger and Cheese


As a web developer, I don’t have many chances to play with mobile app projects. So rather than limit myself to just one field, I love to explore other technologies, especially mobile app development.

Burger Project: My First Xamarin App

Last month, I attended a Xamarin talk at Microsoft Singapore office with my colleague. The talk was about authentication and authorization with social networks such as Facebook and Twitter via Azure App Service: Mobile App.

Ben Ishiyama-Levy is talking about how Xamarin and Microsoft Azure works together.
Ben Ishiyama-Levy is talking about how Xamarin and Microsoft Azure works together.

The speaker is Ben Ishiyama-Levy, a Xamarin evangelist. His talk inspired me to further explore how I could retrieve user info from social network after authenticating the users.

Because I am geek-first and I really want to find out more, so I continue to read more about this topic. With the help from my colleague, I developed a simple Xamarin.Android app to demonstrate the Authentication and logged-in user’s info retrieval.

The demo app is called Burger and it can be found on my Github repository: https://github.com/goh-chunlin/Burger.

Challenges in Burger Project

Retrieving user's info from social network.
Retrieving user’s info from social network.

In Burger project, the first big challenge is to understand how Azure App Service: Mobile App works in Xamarin. Luckily, with the material and tutorial given in the Xamarin talk from Ben, I was able to get a quick start on this.

My colleague also shared another tutorial which is about getting authenticated user’s personal details on Universal Windows Platform (UWP). It helps me a lot to understand about how mobile app and Azure App Service can work together.

My second challenge in this project is to understand Facebook Graph API. I still remember that I spent quite some time finding out why I could not retrieve the friend list of a logged-in Facebook user. With the introduction of the Facebook Graph API 2.0, access to a user’s friends list via /me/friends is limited to just friends using the same app. Hence after reading a few other online tutorials, I finally somehow able to get another subset of a user’s friends via /me/taggable_friends.

In this project, it’s also the first time I apply Reflection in my personal project. It helps me easily get the according social network login class with a neat and organized code.

Microsoft Developer Day at NUS, Singapore in May 2016

Cheese Project: When Google Speech Meets MS LUIS on Android

Few months ago, I’m fortunate to represent my company to attend Microsoft Developer Day 2016 in National University of Singapore (NUS).

The day is the first time Microsoft CEO Satya Nadella comes to Singapore. It’s also my first time learn about the powerful Cognitive Services and LUIS (Language Understanding Intelligence Service) in Microsoft Azure in Riza’s talk.

Riza’s presentation about Microsoft Cognitive APIs during Microsoft Developer Day.

Challenges in Cheese Project

Everyday, it takes about one hour for me to reach home from office. Hence, I will only have two to three hours every night to work on personal projects and learning. During weekends, when people are having fun out there, I will spend time on researching about some exciting new technologies.

There are many advance topics in LUIS. I still remember that when I was learning how LUIS works, my friend was actually playing the Rise of the Tomb Raider beside me. So while he was there phew-phew-phew, I was doing data training on LUIS web interface.

Microsoft LUIS (Language Understanding Intelligence Service) and Intents

Currently, I only worked on some simple intents, such as returning me current date and time as well as understanding which language I want to translate to.

My first idea in Cheese project is to build an Android app such that if I say “Please translate blah-blah to xxx language”, the app will understand and do the translation accordingly. This can be quite easily done with the help of both LUIS and Google Translate.

After showing this app to my colleagues, we realized one problem in the app. It’s too troublesome for users to keep saying “Please translate blah-blah to xxx language” every time they need to translate something. Hence, recently I have changed it to use GUI to provide language selection. This, however, reduces the role played by LUIS in this project.

VoiceText provides a range of speakers and voices with emotions!

To make the project even more fun, I implemented the VoiceText Web API from Japanese in the Android app. The cool thing about this TTS (Text-To-Speech) API is that it allows developers to specify the mood and characteristic of the voice. The challenge, of course, is to read the API written in Japanese. =P

Oh ya, this is the link to my Cheese repository on Github: https://github.com/goh-chunlin/Cheese. I will continue to work on this project while exploring more about LUIS. Stay tuned.

languagelist    googlespeech    SuccessfullyTranslated.png

After-Work Personal Projects

There are still more things in mobile app development for me to learn. Even though most of the time I feel exhausted after long work day, working on new and exciting technologies helps me getting energized again in the evening.

I’m not as hardworking as my friends who are willing to sacrifice their sleep for their hobby projects and learning, hence the progress of my personal project development is kind of slow. Oh well, at least now I have my little app to help me talking to people when I travel to Hong Kong and Japan next year!


Export Scheduled Report in an Excel Spreadsheet as an Email Attachment

People love reports. I do not know why but most of the time, the systems that I am working on always have this report module. The requirements of the report are usually given by the administrative staff. So normally the admin will always give me a sample of existing report as a reference during the development of the report module.

Previously, the admin was happy with just one report module giving them the ability to view reports by using their login id and password. After that, they wanted the function to export the report to Excel so that they could immediately work on the data analysis. Soon, they realized that logging in to the system just to view the report was a bit stupid. Thus, they required an email to be sent to them in midnight with the report in Excel format attached in the email.

Admin Loves Reading Reports (Photo Credit: Kono Aozora ni Yakusoku o)
Admin loves reading reports. Image Credits: Kono Aozora ni Yakusoku o

Although there is this cool stuff called Excel Interactive View which can generate Excel table and charts of  an HTML table on the fly, I don’t really like it. The generated Excel table looks very complicated with colourful bar appearing at the background of the cells containing numbers.

Also, as shown in the following screenshot, the Excel Interactive View does not do a good job because contact number and tutorial class number are wrongly taken as numerical data used to generate the charts. Hence, Excel Interactive View is great and convenient but it does not work in all kinds of reports.

The look-and-feel of Excel Interactive View can be simpler.
The four charts shown at the right are meaningless already.

In ASP.NET, I can have my own “Export to Excel” button by adding in the following codes in the Page_Load method of a web page.

Response.ContentType = "application/vnd.ms-excel";
Response.AddHeader("Content-Disposition", "attachment; filename=\"Sales_Report.xls\"");
string excelBody = "";

excelBody +=
 "<head>" +
 "<meta http-equiv=Content-Type content=\"text/html; charset=utf-8\">" +
 "<style>" +
 "<!--table" +
 "br {mso-data-placement:same-cell;}" +
 "tr {vertical-align:top;}" +
 "-->" +
 "</style>" +
excelBody += "<body>" + <The HTML table goes here...> + "</body>";
excelBody += "</html>";

Then, I just need to redirect the user to this page when the “Export to Excel” button is pressed. This is the code used when admin staff was satisfied with just the functionality to export their reports to Excel.

Soon after that, I found another great library to help generating Excel spreadsheet in C#. It is called excellibrary, which is able to be downloaded on Google Code. Thanks to the library, I am able to do a system which will automatically send out an email attached with Excel report.

To do that, firstly, I need to generate the report in Excel format with the help of excellibrary.

Workbook workbook = new Workbook();
Worksheet wsReport = new Worksheet("Sales Report");
int startingRow = 0;
wsReport.Cells[startingRow, 0] = new Cell("Column 1 Row 1");
wsReport.Cells[startingRow, 1] = new Cell("Column 2 Row 2");
for (int i = startingRow + 1; i < 200; i++)
    wsReport.Cells[i, 0] = new Cell(" "); // Some dummy empty cells

The reason for adding some dummy empty cells in the end is because Excel will complain that it found unreadable content in Sales_Report.xls when the number of cells containing real data is too small. This is a reported issue in the excellibrary project and one workaround suggested by the users is to increase the file size by adding more rows and columns with a space.

Secondly, I send out the email by using the following code.

string sSmtpServer = "smtp.gmail.com";
MailMessage myMessage = new MailMessage();
myMessage.Body = "The report in Excel format is attached in this email.";
myMessage.Subject = "Sales Report in Excel!";
myMessage.To = "...";
// Add the file attachment to this e-mail message.
myMessage.Attachments.Add(new MailAttachment("C:\\ExcelOutputs\\Sales_Report.xls"));
myMessage.Fields["http://schemas.microsoft.com/cdo/configuration/smtpauthenticate"] = 1;
myMessage.Fields["http://schemas.microsoft.com/cdo/configuration/sendusing"] = 2;
myMessage.Fields["http://schemas.microsoft.com/cdo/configuration/sendusername"] = "...";
myMessage.Fields["http://schemas.microsoft.com/cdo/configuration/sendpassword"] = "...";
myMessage.Fields["http://schemas.microsoft.com/cdo/configuration/smtpserverport"] = "465";
myMessage.Fields["http://schemas.microsoft.com/cdo/configuration/smtpusessl"] = "true";
myMessage.From = "...";
myMessage.BodyFormat = MailFormat.Html;
SmtpMail.SmtpServer = sSmtpServer;

Finally, I just need to create a scheduled task to run this little program daily.

Yup, this is how my automatic report exporting and emailing system is done in C#.