This sample shows how to register a workbook activated event handler.

Workbook activated event.EXCEL.yaml

name: Workbook activated event
description: This sample shows how to register a workbook activated event handler.
host: EXCEL
api_set: {}
script:
  content: |
    $("#register-event-handler").click(() => tryCatch(registerEventHandler));

    async function workbookActivated(event: Excel.WorkbookActivatedEventArgs) {
      await Excel.run(async (context) => {
        // Callback function for when the workbook is activated.
        console.log("The workbook was activated.");
      });
    }

    async function registerEventHandler() {
      await Excel.run(async (context) => {
        const workbook = context.workbook;

        // Register the workbook activated event handler.
        workbook.onActivated.add(workbookActivated);

        await context.sync();
        console.log("Added event handler for workbook activated.");
      });
    }

    /** Default helper for invoking an action and handling errors. */
    async function tryCatch(callback) {
      try {
        await callback();
      } catch (error) {
        // Note: In a production add-in, you'd want to notify the user through your add-in's UI.
        console.error(error);
      }
    }
  language: typescript
template:
  content: "<section class=\"ms-font-m\">\n\t<p>This sample shows how to register a workbook activated event handler.</p>\n\t<p>Once the event handler is registered, a notification prints to the console when the workbook is activated. Try\n\t\tswitching to another application and then switching back to Excel to see the console notification.</p>\n</section>\n\n<section class=\"setup ms-font-m\">\n\t<h3>Try it out</h3>\n\t<button id=\"register-event-handler\" class=\"ms-Button\">\n      <span class=\"ms-Button-label\">Register the event handler</span>\n  </button>\n</section>"
  language: html
style:
  content: |-
    section.samples {
        margin-top: 20px;
    }

    section.samples .ms-Button, section.setup .ms-Button {
        display: block;
        margin-bottom: 5px;
        margin-left: 20px;
        min-width: 80px;
    }
  language: css
libraries: |
  https://appsforoffice.microsoft.com/lib/1/hosted/office.js
  @types/office-js

  [email protected]/dist/css/fabric.min.css
  [email protected]/dist/css/fabric.components.min.css

  [email protected]/client/core.min.js
  @types/core-js

  [email protected]
  @types/[email protected]