htp on-line reference : ALTTEXT

syntax

<imageurl url="imageurl" [ path="path/in/local/filesystem" ]>



synopsis

When an IMG tag with a matching source is encountered, htp will add an ALT attribute only if one is not already present. This allows for ALT text to be overridden on specific images and default text on all others.

For example:

  <imageurl url="http://my.domain.org/" path="/var/www/my.domain/">
  <imageurl url="other.domain.org/" path="/var/www/other.domain/">

  For this line: <img src="logo.gif">
  the local filename "logo.gif" will be used to determine image dimensions
  (no URL replacement).

  For this line: <img src="http://my.domain.org/logo.gif">
  the local filename "/var/www/my.domain/logo.gif" will be used.

  But for this line: <img src="http://other.domain.org/logo.gif">
  the local file cannot be found (no prefix match), so the image dimensions
  will not be added.

  Order is important; last IMAGEURL tag takes precedence:
  <imageurl url="/" path="/var/www/htdocs/">
  <imageurl url="/test/" path="/var/www/test/">

  <img src="/image.gif"> and <img src="/test/image.gif"> are mapped to
  /var/www/htdocs/image.gif and /var/www/test/image.gif, resp.
  If the order of the imageurl lines would be swapped, the second
  image would be mapped to /var/www/htdocs/test/image.gif.


An ALTTEXT tag with a name but no text attribute removes any ALT mapping for this image. Successing IMG tags with a matching SRC name are not changed.

Since this is useful for an image used throughout a set of documents, ALTTEXT is most appropriate in an include file or a default file.

In addition to ALTTEXT, htp can also automatically add WIDTH and HEIGHT attributes to IMG tags.