Build an Excel task pane add-in using Vue

06/20/2019
4 minutes to read
- +1

In this article, you'll walk through the process of building an Excel task pane add-in using Vue and the Excel JavaScript API.

Prerequisites

Node.js (version 8.0.0 or later)
The latest version of Yeoman and the Yeoman generator for Office Add-ins. To install these tools globally, run the following command via the command prompt:
```
npm install -g yo generator-office
```
Note

Even if you've previously installed the Yeoman generator, we recommend you update your package to the latest version from npm.

Install the Vue CLI globally.
```
npm install -g vue-cli
```

Generate a new Vue app

Use the Vue CLI to generate a new Vue app. From the terminal, run the following command and then answer the prompts as described below.

vue init webpack my-add-in

When responding to the prompts that are generated by the previous command, override the default answers for the following 3 prompts. You can accept the default answers for all other prompts.

Install vue-router? No
Set up unit tests: No
Setup e2e tests with Nightwatch? No

Vue CLI prompts

Generate the manifest file

Each add-in requires a manifest file to define its settings and capabilities.

Navigate to your app folder.
```
cd my-add-in
```
Use the Yeoman generator to generate the manifest file for your add-in. Run the following command and then answer the prompts as shown below.
```
yo office
```
- Choose a project type: Office Add-in project containing the manifest only
- What do you want to name your add-in? my-office-add-in
- Which Office client application would you like to support? Excel
After you complete the wizard, the generator creates the manifest file.

Secure the app

While not strictly required in all add-in scenarios, using an HTTPS endpoint for your add-in is strongly recommended. Add-ins that are not SSL-secured (HTTPS) generate unsecure content warnings and errors during use. If you plan to run your add-in in Office on the web or publish your add-in to AppSource, it must be SSL-secured. If your add-in accesses external data and services, it should be SSL-secured to protect data in transit. Self-signed certificates can be used for development and testing, so long as the certificate is trusted on the local machine.

To enable HTTPS for your app, open the file package.json in the root folder of the Vue project, modify the dev script to add the --https flag, and save the file.

"dev": "webpack-dev-server --https --inline --progress --config build/webpack.dev.conf.js"

Update the app

In your code editor, open the folder my-office-add-in that Yo Office created at the root of your Vue project. In that folder, you'll see the manifest file that defines the settings for your add-in: manifest.xml.
Open the manifest file, replace all occurrences of https://localhost:3000 with https://localhost:8080, and save the file.
Open the file index.html (located at the root of your Vue project), add the following <script> tag immediately before the </head> tag, and save the file.
```
<script src="https://appsforoffice.microsoft.com/lib/1/hosted/office.js"></script>
```

Open src/main.js and remove the following block of code:

new Vue({
    el: '#app',
    components: {App},
    template: '<App/>'
})

Then add the following code in that same location, and save the file.

const Office = window.Office
Office.initialize = () => {
  new Vue({
    el: '#app',
    components: {App},
    template: '<App/>'
  })
}

Open src/App.vue, replace file contents with the following code, add a line break at the end of the file (i.e., after the </style> tag), and save the file.

<template>
<div id="app">
    <div id="content">
    <div id="content-header">
        <div class="padding">
        <h1>Welcome</h1>
        </div>
    </div>
    <div id="content-main">
        <div class="padding">
        <p>Choose the button below to set the color of the selected range to green.</p>
        <br/>
        <h3>Try it out</h3>
        <button @click="onSetColor">Set color</button>
        </div>
    </div>
    </div>
</div>
</template>

<script>
export default {
  name: 'App',
  methods: {
    onSetColor () {
      window.Excel.run(async (context) => {
        const range = context.workbook.getSelectedRange()
        range.format.fill.color = 'green'
        await context.sync()
      })
    }
  }
}
</script>

<style>
#content-header {
    background: #2a8dd4;
    color: #fff;
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 80px;
    overflow: hidden;
}

#content-main {
    background: #fff;
    position: fixed;
    top: 80px;
    left: 0;
    right: 0;
    bottom: 0;
    overflow: auto;
}

.padding {
    padding: 15px;
}
</style>

Start the dev server

From the terminal, run the following command to start the dev server.
```
npm start
```
In a web browser, navigate to https://localhost:8080. If your browser indicates that the site's certificate is not trusted, you will need to configure your computer to trust the certificate.
After your browser loads the add-in page without any certificate errors, you're ready test your add-in.

Try it out

Follow the instructions for the platform you'll be using to run your add-in and sideload the add-in within Excel.
- Windows: Sideload Office Add-ins on Windows
- Web browser: Sideload Office Add-ins in Office on the web
- iPad and Mac: Sideload Office Add-ins on iPad and Mac
In Excel, choose the Home tab, and then choose the Show Taskpane button in the ribbon to open the add-in task pane.
Select any range of cells in the worksheet.
In the task pane, choose the Set color button to set the color of the selected range to green.

Next steps

Congratulations, you've successfully created an Excel task pane add-in using Vue! Next, learn more about the capabilities of an Excel add-in and build a more complex add-in by following along with the Excel add-in tutorial.

Excel add-in tutorial