On 10/25/2011 2:37 PM, Dave Potts wrote:
Is there any way of controling drawfeature such that is only possible to
insert one point and that a 2nd attempt insertation generates an error?
Sure. You're already handling the "featureadded" event to save your
point or do something with it, right?
Make a similar handler, for the "beforefeatureadded" event. Like the
"featureadded" it takes a feature as its argument. Check
feature.layer.features.length and you'll know that a point has already
been added. Return false to cancel the addition of the new feature.
layer.events.register('beforefeatureadded', layer, function (feature) {
if (layer.features.length > 0) {
alert('One at a time please');
return false;
}
return true;
});
An additional thought:
* You can have your "featureadded" event handler deactivate the
drawFeature control. This would prevent someone from drawing more than
one feature per activation.
* You could then add a onactivate event handler to your drawFeature
control, which calls layer.removeAllFeatures() to remove any previous
drawing.
Between these two, you would be assured they could never insert a second
feature accidentally: only one shape is drawn at a time, and opening the
drawing tool again erases the previous one.
--
Greg Allensworth, Web GIS Developer
BS A+ Network+ Security+ Linux+ Server+
GreenInfo Network - Information and Mapping in the Public Interest
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