Loading dynamic data from a text file.
The vector layer shown uses the BBOX strategy, the HTTP protocol,
and the Text format.
This setup appends "?bbox=west,south,east,north" to every
request. This allows you to configure the location as something
like 'textfile.php', and take the '?bbox=' parameter to select
data from a database or the like.
There is nothing about this example that limits it to text files;
you can do the same thing with KML, GeoJSON, etc.
This is an alternative to something like the
OpenStreetMap "Dynamic POI" example. The Layer is a standard vector layer, and interaction can be
configured via the SelectFeature control, as you can see in the
latter half of the code, which allows you to open a popup when
a feature is selected.