Drawing Object Features Supported on HTML Export

Images

All images are exported as the same format that they were originally loaded as.

Most drawing objects are exported using the img element unless there is native support for the feature. HTML does not have support for a lot of Word graphics options therefore these features are rendered to image before export. There are options to choose a folder or streams to save images during export to HTML. There is also an option to export image data embedded in the HTML as base64. You can export the document as MHTML to automatically embed all image data.

You can control the name of the generated image file by using the ImageSavingCallback in the HtmlSaveOptions class.

Currently, images are only exported as absolute size (points) and not in percent. This means that images will not resize when the “Increase Text/Decrease Text” buttons are pressed. These buttons are common in browsers and eReaders.

This feature will be supported in the future.

See the following links in the documentation for further information:

  • HtmlSaveOptions.ImageFolder
  • HtmlSaveOptions.ImageSavingCallback
  • HtmlSaveOptions.ExportImagesAsBase64
  • HtmlSaveOptions.ImageResolution
Feature Supported Comment See Also
PNG Yes    
JPG Yes    
WMF Yes Metafiles such as WMF, EMF and EMF+ are normally converted to PNG when exporting to HTML. There is an option to export metafiles as vector images.

Note that not all browsers can display metafiles properly.		 - HtmlSaveOptions.ExportMetafileAsRaster
EMF Yes    
EMF+ Yes    
BMP Yes    
GIF Yes    
TIFF Yes    
Borders Yes Some borders can be represented natively by HTML elements and attributes. Others are output in raster form.

Native borders are exported as “border-XXX” on style attribute e.g border-style, border-width.		  
Cropping Yes Rectangular cropping is supported only.

Images are cropped permanently and cropping cannot be removed after export.		  
Alternative text Yes Exported as “alt=xxxx” on img element.  

Image Recoloring

Feature Supported Comment See Also
Brightness Yes    
Contrast Yes    
Recolor Planned Image is currently exported without any recoloring applied.  

Textboxes

Textboxes are converted to raster images on export.

This provides great fidelity however text is not selectable in the output document.

Feature Supported Comment See Also
Text Direction Yes    
Linked Textboxes Planned    
Internal Margins Yes    
Vertical Alignment Yes    
Resize To Fit Text Planned The textbox is currently exported as the size set as Width and Height properties of Shape.l  
Text in Other Shapes Yes    

OLE Objects

OLE Objects represent embedded content in a Microsoft Word document, such as an embedded Excel or Powerpoint document. The OLE object is dynamic and can be edited or updated through Microsoft Word.

OLE objects are fully preserved when converting within different Word document formats.

OLE objects are saved as images.

There are plans to export using the <object> tag and the type of object which is embedded. This will allow the export of embedded objects such as PDF to be exported as working objects.

Feature Supported Comment See Also
Linked N/A    
Embedded N/A    
Draw Aspect N/A    
Auto Update N/A    
Lock N/A    
Ole Object Data N/A    
Ole Object Picture Yes    
Source Range N/A    

ActiveX Controls

Output as an image.

Feature Supported Comment See Also
Persistent Properties Storage N/A    

Shapes

Shapes are converted to raster images on export.

This provides great fidelity however text is not selectable in the output document.

See the following link in the documentation for further information:

  • HtmlSaveOptions.ScaleImageToShapeSize
Feature Supported Comment See Also
Lines Yes Vector shapes (lines, arrows, callouts etc.) are output in rasterized form.  
Basic Shapes Yes    
Block Arrows Yes    
Flowcharts Yes    
Callouts Yes    
Stars and Banners Yes    
Group Shape Yes All grouped shapes are exported as one image.  
Drawing Canvas Yes    
Signature Line N/A HTML does not have any signature line feature. A signature line is exported as a regular image.

Alternative text on the image of the signature line is exported as “alt=xxx” attribute.		  
Ink Annotation Planned Ink Annotations are exported to all formats as regular images.  
Clip Art Yes    
Diagrams (VML) Yes VML graphic format is normally used in pre-OOXML formats such as DOC or RTF.

It is planned to also export the VML code along with the image to allow proper round-trip.		  
SmartArt (VML) Yes    
Charts (VML) Yes    
Shape Customizations Yes Exported as image.  
Hyperlink on Shape Yes Exported as <img> element wrapped in <a> element with appropriate attributes.  
Watermark N/A Watermark shapes will be exported as a regular image to HTML at the same level as normal content. This is because there is no native support for the watermark in HTML. To increase fidelity, set the watermark wrapping to “Behind Text” so the watermark will appear behind the main document content when exported to HTML.

Also, note that the image will not have the same transparency level as what is applied in Microsoft Word.

Watermarks are only exported if the export of headers and footers to HTML is enabled. Since HTML has no “page” concept, the headers and footers only appear once. There is a save option to control how headers and footers are exported to HTML.		  

WordArt

WordArt is exported as an image. You can also set the AltText property so the plain text content of the WordArt can be found in the output HTML.

Feature Supported Comment See Also
Styles Yes    
Outline Yes    
Fill Yes    
3D Properties Planned    
Text Spacing Planned    
Vertical Text Planned Exported as rotated text.  
Even Height Planned    
Align and Justify Text Planned    
WordArt Shape Planned    

Horizontal Line Object

Exported as <hr> tag.

Feature Supported Comment See Also
Width Yes Exported as width:XXX% on style attribute.  
Height Yes Exported as height:XXpt on style attribute.  
Color Yes Exported as color:XXX along with border:none on style attribute.

Note that some browsers cannot display this properly (Chrome seems to ignore this).

We will consider using a different attribute in a future version.		  
Alignment Yes Exported as “text-align:XXX” on style attribute.  
Hyperlink Planned <hr> tag can be wrapped in an <a> element.  
Image Yes Exported as a regular <img> element instead of <hr>.

There are plans to export a horizontal line with an image as <hr> element with style=“background: url(xxx.png)”.		  

Position

Feature Supported Comment See Also
Inline Yes Exported as child element child of <p>.  
Floating Yes Aspose.Words attempts to export floating content to HTML. Note that the output produced may differ greatly from the Word document source as a Word document is a vastly different format. We are actively improving the export of floating content in our HTML engine.

Floating content is made possible by exporting elements with margin-top and margin-left style and position:absolute style.

In the future, we will provide tips on how to design Word documents with floating content that are exported to HTML based formats well.		  
Wrap Type Yes

Text wrapping around images and shapes is supported in all formats.

Wrap type is emulated through the use of “float” on style attribute.

- Square, Tight and Through are exported as “float:left”.

- Top and Bottom can be emulated by adding <br style=“clear:both”> around image but is currently exported as “float:left”.

- Behind-Text can be emulated using z-index:-1 but is currently such content is exported on top of the text.

- In front of Text content is exported with a z-index greater than 0.

  
Wrap Sides Yes

Wrap sides are exported through the use of the float style attribute.

- Both sides and largest only wrap have no suitable analog in HTML and are exported as float:left.

- Right side wrap is exported as float:left.

- Left side wrap is exported as float:right.

  
Distance from Text Yes Exported as margin style on the exported object.  
Z-Order Yes Exported as “z-index:X” on style attribute.  
Polygon Wrap Points N/A    
Rotation Yes Image is rotated when rendering shape to a raster image.  
Flip Yes Image is flipped when rendering shape to a raster image.  
Horizontal Alignment Planned Currently exported as an absolute position. This will be supported in a future version.

An alternative to achieve the same effect is to make the image inline in a paragraph and set the paragraph alignment to centre.		  
Horizontal Position Relative To Yes Always exported as the distance from the anchor (paragraph or character).  
Vertical Alignment Planned Currently exported as an absolute position. This will be supported in a future version.  
Vertical Position Relative To Yes Always exported as the distance from the anchor (paragraph or character).  
Anchor Lock N/A    
Allow Overlap Yes Floating content can overlap when “Allow Overlap” is enabled.

When disabled the HTML engine will export these as separate content that does not overlap.		  
Layout in Table Cell N/A Floating content is always exported as the distance from the anchor (paragraph or character) regardless of whether the paragraph is in a table or not.  

Size

Feature Supported Comment See Also
Width and Height Yes Exported as height and width attributes in pixels (no units specified).  
Scale Yes A scaled object is normally exported with scaling applied to the Shape size and the Scale property reset to 100%.

Exported as explicit size as height and width attributes in pixels (no units specified).		  
Relative Size Yes Exported as explicit size as height and width attributes in pixels (no units specified).  
Lock Aspect Ratio N/A    

Fill

Feature Supported Comment See Also
No Fill Yes Shape with no fill is rendered to image as transparency enabled to achieve this effect.  
Solid Fill Yes All shapes are raster to image in HTML output.  
Gradient Fill Yes The gradient is rendered to a raster image.  
Pattern Fill Yes Rendered to a raster image.  
Picture or Texture Fill Yes Rendered to a raster image.  

Line Style

Line shapes are rendered to image and embedded in the output HTML.

Feature Supported Comment See Also
Line Color Yes    
Line Fill Yes    
Line Width Yes    
Compound Type Yes    
Dash Type Yes    
Cap Type Yes    
Join Type Yes    
Arrow Settings Yes    

Shadow

Shadow is currently lost on shapes on export to HTML.

There are plans to rasterize the shadow properties on the image during export to HTML.

Feature Supported Comment See Also
Shadow Planned    

3D Properties

3D effects on shape are lost upon conversion to HTML.

There are plans to rasterize the 3D properties on the image during export to HTML.

Feature Supported Comment See Also
3D Properties Planned    
HTML Export - Document Features HTML Export - Field Features