Build your first OneNote task pane add-in
In this article, you'll walk through the process of building a OneNote task pane add-in.
Prerequisites
Node.js (the latest LTS version). Visit the Node.js site to download and install the right version for your operating system.
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.
Office connected to a Microsoft 365 subscription (including Office on the web).
Note
If you don't already have Office, you might qualify for a Microsoft 365 E5 developer subscription through the Microsoft 365 Developer Program; for details, see the FAQ. Alternatively, you can sign up for a 1-month free trial or purchase a Microsoft 365 plan.
Create the add-in project
Run the following command to create an add-in project using the Yeoman generator. A folder that contains the project will be added to the current directory.
yo office
Note
When you run the yo office
command, you may receive prompts about the data collection policies of Yeoman and the Office Add-in CLI tools. Use the information that's provided to respond to the prompts as you see fit.
When prompted, provide the following information to create your add-in project.
- Choose a project type:
Office Add-in Task Pane project
- Choose a script type:
Javascript
- What do you want to name your add-in?
My Office Add-in
- Which Office client application would you like to support?
OneNote
After you complete the wizard, the generator creates the project and installs supporting Node components.
Explore the project
The add-in project that you've created with the Yeoman generator contains sample code for a very basic task pane add-in.
- The ./manifest.xml file in the root directory of the project defines the settings and capabilities of the add-in.
- The ./src/taskpane/taskpane.html file contains the HTML markup for the task pane.
- The ./src/taskpane/taskpane.css file contains the CSS that's applied to content in the task pane.
- The ./src/taskpane/taskpane.js file contains the Office JavaScript API code that facilitates interaction between the task pane and the Office client application.
Update the code
In your code editor, open the file ./src/taskpane/taskpane.js and add the following code within the run
function. This code uses the OneNote JavaScript API to set the page title and add an outline to the body of the page.
try {
await OneNote.run(async (context) => {
// Get the current page.
const page = context.application.getActivePage();
// Queue a command to set the page title.
page.title = "Hello World";
// Queue a command to add an outline to the page.
const html = "<p><ol><li>Item #1</li><li>Item #2</li></ol></p>";
page.addOutline(40, 90, html);
// Run the queued commands.
await context.sync();
});
} catch (error) {
console.log("Error: " + error);
}
Try it out
Navigate to the root folder of the project.
cd "My Office Add-in"
Start the local web server. Run the following command in the root directory of your project.
npm run dev-server
Note
Office Add-ins should use HTTPS, not HTTP, even while you're developing. If you're prompted to install a certificate after you run one of the following commands, accept the prompt to install the certificate that the Yeoman generator provides. You may also have to run your command prompt or terminal as an administrator for the changes to be made.
If this is your first time developing an Office Add-in on your machine, you may be prompted in the command line to grant Microsoft Edge WebView a loopback exemption ("Allow localhost loopback for Microsoft Edge WebView?"). When prompted, enter
Y
to allow the exemption. Note that you'll need administrator privileges to allow the exemption. Once allowed, you shouldn't be prompted for an exemption when you sideload Office Add-ins in the future (unless you remove the exemption from your machine). To learn more, see "We can't open this add-in from localhost" when loading an Office Add-in or using Fiddler.
In OneNote on the web, open a notebook and create a new page.
Choose Insert > Office Add-ins to open the Office Add-ins dialog.
If you're signed in with your consumer account, select the MY ADD-INS tab, and then choose Upload My Add-in.
If you're signed in with your work or education account, select the MY ORGANIZATION tab, and then select Upload My Add-in.
The following image shows the MY ADD-INS tab for consumer notebooks.
In the Upload Add-in dialog, browse to manifest.xml in your project folder, and then choose Upload.
From the Home tab, choose the Show Taskpane button on the ribbon. The add-in task pane opens in an iFrame next to the OneNote page.
At the bottom of the task pane, choose the Run link to set the page title and add an outline to the body of the page.
When you want to stop the local web server and uninstall the add-in, follow these instructions:
To stop the server, run the following command.
npm stop
To uninstall the sideloaded add-in, see Remove a sideloaded add-in.
Next steps
Congratulations, you've successfully created a OneNote task pane add-in! Next, learn more about the core concepts of building OneNote add-ins.
Troubleshooting
Ensure your environment is ready for Office development by following the instructions in Set up your development environment.
Some of the sample code uses ES6 JavaScript. This isn't compatible with older versions of Office that use the Trident (Internet Explorer 11) browser engine. For information on how to support those platforms in your add-in, see Support older Microsoft webviews and Office versions. If you don't already have a Microsoft 365 subscription to use for development, you might qualify for a Microsoft 365 E5 developer subscription through the Microsoft 365 Developer Program; for details, see the FAQ. Alternatively, you can sign up for a 1-month free trial or purchase a Microsoft 365 plan.
- The automatic
npm install
step Yo Office performs may fail. If you see errors when trying to runnpm start
, navigate to the newly created project folder in a command prompt and manually runnpm install
. For more information about Yo Office, see Create Office Add-in projects using the Yeoman Generator.
See also
Office Add-ins