Some Examples


Queryable Layer

Here we want to query a layer, based on the state of another one. The queried layer has points (displayed as red crosses), representing random Montreal addresses:

LAYER
    TEMPLATE tmpl
    NAME "random_montreal_addresses"
    TYPE point
    DATA "random_montreal_addresses.shp"
    FILTERITEM "id"
    CLASS STYLE COLOR 255 0 0  SYMBOL "cross" SIZE 5 WIDTH 1 END END
END

The presence of a FILTERITEM attribute informs Dracones that this layer is to be queryable, meaning that nothing will be displayed on it until a filter allowing some values is set. The creation of this particular query involves the definition of a customized Python function, using services from the Dracones Core API. Other types of queries and customized behaviors can be easily designed, in a similar way.

Hover Items

One other feature is at work here: when hovering with the mouse over the query results, an information tooltip is displayed. The HTML format and content of this tooltip is easily configurable.

This map works as the previous ones: pan it by dragging with the left mouse button, zoom in/out as before, by using the mouse wheel, or by double-clicking (in), or SHIFT + double-clicking (out). After having selected one or more regions, by holding the CTRL button (while clicking or dragging), you can launch the query by pressing the button below:


Go to another example.