Office 365 Development With Visual Studio 2017 - Part Two

When Visual Studio 2017 was launched earlier this year, I wrote an article to provide a glimpse of how to get started with Office 365 development with VS 2017 and different project templates available in VS 2017. You can read it here.

Let’s continue our journey of Office 365 development with VS 2017 in this article.

Objectives

In this article, we will walk through creating and running Office 365 projects in VS 2017. Along with that, I will explain Office 365 Add-in concepts side by side.

We will learn the following in this article.

  • Creation of Excel add-in projects
  • Brief intro of Office 365 Add-in
  • When you should choose which type of project

Prerequisite

This article assumes that you already have installed Visual Studio 2017 with Office 365 development option on your PC. If not, then please read part-1 and follow the installation steps. You will not see the project templates mentioned in this article if you don’t have the correct version of Visual Studio with Office 365 development option.

To make sure which version of Visual Studio you are using, go to “Help” menu and select “About Microsoft Visual Studio” submenu in Visual Studio.

Make sure you are using Visual Studio 2017.

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I’m using Community edition of VS 2017 which is “Free, fully-featured IDE for students, open-source and individual developers”.

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Image credit: Microsoft

You can download VS 2017 Community edition here.

The Office 365 development options are same in all editions of VS 2017, namely Community, Professional, and Enterprise. So, it will not matter whichever edition of VS 2017 you have for following the steps of this article.

Getting Started

Let’s start with creating a new Office 365 project for the add-in.

Either click on the menu “File” -> “New” -> “Project” or on the “Start Page” under “New Project” section, click on “Create new project…”:

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In the "New Project" popup, expand “Office/SharePoint” category under Visual C# and click on “Add-ins”.

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You will see project templates for Word, Excel, PowerPoint, Outlook, and SharePoint add-in.

Let’s briefly understand about Office 365 add-ins.

What is Office 365 add-in?

With Office 365 add-in or Office add-in, you can build program/solution that extends Office applications and interacts with the content in Office documents. You can add new functionality to Microsoft Office clients or create new rich, interactive objects that can be embedded in Microsoft Office documents. Office add-in runs in Microsoft Office across multiple platforms, including Office for Windows, Office Online, Office for the Mac, and Office for the iPad.

For more information on Office 365 add-ins, read on Microsoft website here. I will cover more on Office 365 add-ins in a separate article later.

In the New Project popup, select “Excel Web Add-in”, then click OK.

You will see a “Create Office Add-in” dialog with following two options:

  • Add new functionalities to Excel.
  • Insert content into Excel spreadsheets.

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Let’s quickly see what this means. We will understand by inserting some add-in in Excel.

Open Excel and create a new workbook. Go to “Insert” -> “My Add-ins” -> “See All…”:

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“Office Add-ins” dialog will open. Click on “STORE”, enter “Wikipedia” in search, once Wikipedia add-in appears, click on “Add” button next to it.

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The dialog box will close and you will see now that the “Wikipedia” add-in is added under “Add-ins” ribbon.

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Click on it and on the right side, you will see a new section.

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Anything you can do on Wikipedia website, now you can do from inside Excel only using this add-in.

This is an example of “Extend functionality” type of add-in. These types of add-ins let you do some work right from Office applications without opening any other application. If you want to create this type of add-in, you should select “Add new functionalities to Excel” option in “Create Office add-in” dialog.

Now, let’s see some other add-in examples. Once again in Excel, go to “Insert” -> “My Add-ins” -> “See All…”. In the “Office Add-ins” popup, click on “STORE” tab and search on “bubbles”,

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Click on the first row “Add” button. You will see in the top right under “Insert” ribbon, a new “Excel Bubbles” add-in is available now.

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Click on it and a section with bubbles is added into current worksheet.

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Click on the “Sample Table” bubble in this section. It will add some sample data in worksheet and populate bubbles as per data,

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This is an example of “Content” type of add-in which adds some content inside an Office application. If you want to create this type of add-in then you should select “Insert content into Excel spreadsheets” option in “Create Office add-in” dialog.

Let’s go back to Visual Studio now. We were on this popup,

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Let the selection be “Add new functionalities to Excel”. Click “Finish”.

VS will create a new Excel add-in solution with 2 projects,

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Before understanding “what” these projects are and “why” they are created, let’s first understand the composition of an Office 365 add-in.

An Office 365 add-in consists of two components,

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Image credit: Microsoft

  • XML manifest file
    specifies settings and capabilities of the add-in
  • Web application
    interacts with Office clients and documents
    In VS 2017 Solution Explorer, you will see these two projects,
  • ExcelWebAddIn1
    This is the manifest project containing the XML add-in configuration/settings
  • ExcelWebAddIn1Web
    This is the project which has all code defining the add-in & its interaction with Office document. It has JavaScript and HTML files which define the UI of the add-in.

    To provide same look and feel in the add-in as Office 365 clients, it uses Office UI Fabric JavaScript. I will cover more on Office UI Fabric JS in separate article later.

Let’s now run the project to see it working. Press F5, VS will build the solution and launch Excel to make your add-in available inside it.

In Excel, “Show Taskpane” button will be focused with a tool tip message,

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Click on the “Show Taskpane” button. The task pane area will be loaded on the right side of Excel worksheet.

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Please note that when you created a new Excel add-in project, VS 2017 has included some sample code in it. That’s why you see the text and button here. Also, if you note the worksheet has been loaded with some sample data,

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This sample add-in is for finding and highlighting highest value cell among the selected ones. To see it in action, select the sample data and click on “Highlight” button,

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The JS code will get executed and highest value cell among the selected cells will be highlighted.

Stop the running project from Visual Studio and let’s now see the code which made it work.

In the Solution Explorer, double click the “Home.html” file.

This is the file which contains all UI elements. The texts and button you saw in Excel add-in are defined here,

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In the Solution Explorer, double click on home.js file.

This is the file which contains all code to interact with Excel.

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It sets the button text to “Highlight” and also sets the JS function which should be executed when someone clicks on it, among other things.

The load sample data JS function which populates the worksheet with some random numbers,

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The code for finding the highest value cell and highlighting it,

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See how simple it is to get started with Office 365 add-in development? You must give it a try yourself using VS 2017.

The purpose of this article was to make developers aware of Office 365 add-in development using VS 2017 which I have done above. You have to come up with the idea of your add-in to create a real-life Office 365 add-in which adds some value to the Office clients.

That’s it for this article. I will cover more add-in options in next article.