EPPlus 6 introduces the ability to export a table or a range to HTML/CSS. The best way to get started with this functionality is to have a look at the examples in our web samples project

This feature supports integration of spreadsheet data and styling into web applications - and it is not an implementation of Excel's "Save the workbook as html" feature. Our intention is to make EPPlus a useful tool for bringing the spreadsheet model to web applications rather than providing a pixel-perfect html-representation of an existing workbook.

The spreadsheet data is always exported as a html table. The html has support for accessibility (aria-*) attributes that can be configured when exporting the data. You can also get the raw cell data and javascript compatible datatypes included via data-* attributes in order to use the exported table not only as a UI element but also as a data carrier.

EPPlus separates styling from html and creates a separate stylesheet (css) for the exported data. The classes in this stylesheet are created based on the internal Excel styles. This is per default based on the built in Office theme, but you can easily switch to another theme as demonstrated our html sample 1. EPPlus will export css for table styles when exporting a table. NOTE: Exporting a range that contains a table will not include the table styles in the css.

Images in the cells will be included by default as base64 encoded strings in the stylesheet. Images are per default not included in the export, for more details see this chapter.

We will add new features to this export over time, but please note that some Excel features such as charts, shapes, pivot tables, sparklines and threaded comments are included in the export. Full support for conditional formatting was added in version 7.2.

You can export html/css either from a range or from a a table in your workbook. This is done via the CreateHtmlExporter() function, see below:
Please note that table styles are not included in the css, if you export a range that contains a table via the ExcelRangeBase.CreateHtmlExporter().

var exporter = sheet.Cells["B5:M19"].CreateHtmlExporter();
var html = exporter.GetHtmlString();
var css = exporter.GetCssString();

This export will contain the css for the table style as well as any cell style css.

var exporter = sheet.Tables[0].CreateHtmlExporter();
var html = exporter.GetHtmlString();
var css = exporter.GetCssString();

You can also create an exporter for several ranges at once to get a shared css for multiple ranges over multiple worksheets. Our web sample 6 shows how to do this in detail.

var exporter = package.Workbook.CreateHtmlExporter(
                 package.Workbook.Worksheet[0].Cells["B5:M19"],
                 package.Workbook.Worksheet[1].Cells["A1:D35"]
);

//This will get the html for the first range, B5:M19  in the first sheet
var html1 = exporter.GetHtmlString(0);
//This will get the html for the first range, A1:D35 in the second sheet
var html2 = exporter.GetHtmlString(1);
//This gets the combined css for both ranges.
var css = exporter.GetCssString();

There are async versions of GetHtmlString() and GetCssString(), suffixed with "Async". Other methods renders html and css on a System.IO.Stream, see RenderHtml(stream), RenderHtmlAsync(stream), RenderCss(stream) and RenderCssAsync(stream).

Use the properties below to set the id attribute and add additional css classes on the exported html table.

var settings = exporter.Settings;
settings.TableId = "currency-table";
settings.AdditionalTableClassNames.Add("table");
settings.AdditionalTableClassNames.Add("table-sm");
settings.AdditionalTableClassNames.Add("table-borderless");

Via the Settings property on the exporter you can control how the html is exported. This class has the following properties:

Settings controling the css output.

Pictures/images are not exported per default, but this can be enabled like this:

exporter.Settings.Pictures.Include = ePictureInclude.Include;

The ePictureInclude enum has three members: Exclude (pictures will not be included), IncludeInCssOnly (pictures will be included in css only, so they can be added manually) and Include.

Here are the parameters you can set via the Exporter.Settings.Picture property.

In html you can add custom attributes that is prefixed with "data-". In EPPlus we have added two attributes to the exported table elements: data-value and data-datatype.

Our web sample 4 demonstrates how these attributes can be used.

This attribute is added either on the table.thead.tr.th element or on the table.tbody.tr.td element. See the table below for how the .NET datatypes from EPPlus are mapped to the exported html.

See below how the data-datatype attribute is included in the html of an exported table.

<thead role="rowgroup">
    <tr role="row">
      <th data-datatype="string" class="epp-al" role="columnheader" scope="col">Country</th>
      <th data-datatype="string" class="epp-al" role="columnheader" scope="col">FirstName</th>
      <th data-datatype="string" class="epp-al" role="columnheader" scope="col">LastName</th>
      <th data-datatype="datetime" class="epp-al" role="columnheader" scope="col">BirthDate</th>
      <th data-datatype="string" class="epp-al" role="columnheader" scope="col">City</th>
    </tr>
  </thead>

This attribute will contain the raw value of the cell, see the datatypes table above. Here is an example:

<tr role="row" scope="row">
  <td role="cell">Scotland</td>
  <td role="cell">Autumn</td>
  <td role="cell">Toy</td>
  <td data-value="-1485302400000" role="cell" class="epp-ar">1922-12-08</td>
  <td role="cell">New Andrewhaven</td>
</tr>

Note that this attribute is only present if the raw value differs from the formatted value (the content of the td element).

Accessibility attributes are included by default. Here is an example on how to set the aria-label attribute on the exported table:

var exporter = sheet.Cells["B5:M19"].CreateHtmlExporter();
exporter.Settings.Accessibility.TableSettings.AriaLabel = "This html-table is exported from EPPlus";

results in:

<table class="epplus-table" role="table" aria-label="This html-table is exported from EPPlus">

If you don't want to include accessibility attributes in the html set the below property to false:

exporter.Settings.Accessibility.TableSettings.AddAccessibilityAttributes = false;

Via the exporter's Settings.Accessibility.TableSettings property you can set the following attributes:

• Sample 2.5 (C#) and Sample 2.5 (VB.NET)
• EPPlus Web samples
• Export data