Hi,
Recently we
implemented some functionality that retrieves the width and height of
images in mmbase. Although other solutions may already exist we
thought this might be interesting to some of you.
In order to retrieve
these properties from an image we've used ImageInfo, a freely available java
class, downloadable at: http://www.geocities.com/marcoschmidt.geo/image-info.html.
Imageinfo is used by the added ImageBuilder class, which introduces to
new virtual fields to an image node, width and height. This class has
to be defined in the image builder configuration file like this:
<classfile>nl.kennisnet.cpb.cloud.builders.ImageBuilder</classfile>
As an example of how
this could be used, consider a neatly fitting image popup without whitespace
around the image. The jsp code looks something like this:
<mm:node
number='<%=imageNumber%>'>
<a href="" target="_blank">
</mm:node>
<a href="" target="_blank">
</mm:node>
Where NewWindow is a
small _javascript_ function that creates the popup with the proper width and
height.
Using these extra
virtual fields one can also size an image using the width and height attributes
within the HTML image tag, provided that no scaling is taking place using a
template attribute. The advantage of this is that
the pagelayout remains fixed when the page is being loaded by a browser
over a slow connection. Now, images only take the correct space after they have
been loaded completely. (Sometimes this is regarded as an undesirable
phenomenon)
Robin van
Meteren
Kennisnet
ImageBuilder.java
Description: ImageBuilder.java
