Hello.

I am a beginner in developing Tableau Extensions.

I’ve started recently to develop a new extension as per suggestion of Keshia Rose.   

(TABLEAU version 2018.2)

Now I am facing one un-expected behavior that I need some help or guidance.

In the below code (index.html) I am struggling to get the worksheet name available on the dashboard and I don’t know the reason of this strange behavior. As you can see below, I’ve tried 3x different approaches but without success.

My final goal is to draw a chart (for example a Doughnut) with data coming from the Tableau datasource - as per steps within:

https://tableaumagic.com/creating-a-tableau-extension-part-two/

  <script src="js/tableau-extensions-1.latest.min.js"></script>

  <canvas id="doughnut" width="1300" height="900"></canvas>

  <script>

  //initialise the tableau object, wait for the promise to return and grab the name of the dashboard

tableau.extensions.initializeAsync().then(() => {

    drawChartJS();

  });

   // This javascript function gets data from a specific worksheet and draws the Doughnut.

   function drawChartJS() {

   // Gets all the worksheets in a Tableau Dashboard

   // 1st option

   let dashboard = tableau.extensions.dashboardContent.dashboard;

   dashboard.worksheets.forEach(function (worksheet) {

      if (worksheet.name === 'worksheetData')

      {      

        alert('The correct sheet!!!');

      }

    });

   // 2nd option

   tableau.extensions.dashboardContent.dashboard.worksheets.forEach(function (worksheet){window.alert(worksheet.name)});

   // 3rd option

   const worksheets = tableau.extensions.dashboardContent.dashboard.worksheets;

   var worksheet = worksheets.find(function (sheet) {

      return sheet.name === "worksheetData";

   });

  // Call a function on the worksheet Object to get the Summary Data

  // worksheet.getSummaryDataAsync().then(function (sumdata) {

  //window.alert("worksheetData is found!!!");

  //});

   // Dashboard name     

   window.alert("The dashboard name is ? " + dashboard.name );

   // Render the doughnut 

   var options = {

    …

NOTE:

In the 3^rd option if I include the below code then the extension stops.

   // Call a function on the worksheet Object to get the Summary Data.

       worksheet.getSummaryDataAsync().then(function (sumdata) {

               window.alert("worksheetData is found!!!");

     });

I can see in Tableau side that initialization of this extension is working fine (tableau.extensions.initializeAsync()) because I can see the alert popping up with the dashboard name.

However, I don’t get any alert for the existing worksheets (as you can see below we have 3x sheets + 1x dashboard):

Please advise or suggest any options.

Regards

Armando Santos

PS .Attached the trex + index (full code) files for your evaluation.