Office.js Excel Online > chart.getImage() errors

Question

Summary: Some charts (when not the first chart), cause errors in Excel Online with chart.getImage().

Usage scenario: I use chart.getImage() to get the base64 encoded image so charts can be programmatically inserted into Word/PowerPoint documents. It is used in the Excel-to-Word Document Automation Add-In.

• There is never an issue with Excel for Windows or Mac. Issue only occurs with Excel Online.
• Error only occurs with some chart types, such as Pareto, Funnel, and common charts with some customization
• Error is not consistent: cannot always predict it, same chart, same code sometimes works fine.
• Position of chart seems to matter. First chart added never seems to produce errors.
• Type of error is not consistent. Is either: UnsupportedOperation, GeneralException, or ValueNotLoaded.
• Method details are here: https://dev.office.com/reference/add-ins/excel/chart

Is this a bug that can be fixed? Is there a known workaround?

Simplified Code that can reproduce error (in Script Lab):

function run() {
  Excel.run(function(ctx) {
    var chart = ctx.workbook.worksheets
      .getItem("Sheet1")
      .charts.getItem("Chart3");
    var image = chart.getImage();
    return ctx.sync().then(function() {
      var data = image.value;
      console.log("Success: " + data.substr(0, 100));
    });
  }).catch(function(error) {
    console.log("Error: " + error);
    if (error instanceof OfficeExtension.Error) {
      console.log("Debug info: " + JSON.stringify(error.debugInfo));
    }
  });
}

Sample Error Returns (I've encountered 3 types from this getImage() issue):

{
  "code": "UnsupportedOperation",
  "message": "This operation is not implemented.",
  "errorLocation": "Chart.getImage",
  "statement": "item.getImage(undefined, undefined, undefined);",
  "surroundingStatements": [
    "var workbook=context.workbook;",
    "var worksheets=workbook.worksheets;",
    "var worksheet=worksheets.getItem(\"Sheet1\");",
    "var charts=worksheet.charts;",
    "var item=charts.getItem(\"rpt_Chart3\");",
    "// >>>>>",
    "item.getImage(undefined, undefined, undefined);",
    "// <<<<<"
  ]
}

{
  "name": "OfficeExtension.Error",
  "code": "GeneralException",
  "message": "An internal error has occurred.",
  "traceMessages": [],
  "innerError": null,
  "debugInfo": {
    "code": "GeneralException",
    "message": "An internal error has occurred."
  }
}

{
  "name": "OfficeExtension.Error",
  "code": "ValueNotLoaded",
  "message":
    "The value of the result object has not been loaded yet. Before reading the value property, call \"context.sync()\" on the associated request context.",
  "traceMessages": [],
  "innerError": null,
  "debugInfo": {
    "code": "ValueNotLoaded",
    "message":
      "The value of the result object has not been loaded yet. Before reading the value property, call \"context.sync()\" on the associated request context.",
    "errorLocation": "clientResult.value"
  }
}

Answer 1

this is potentially a bug and the team is working on fixing it. Will update this answer as the fix becomes available. thanks! Juan.