[Qgis-developer] Adding features to empty layer

[Barry Rowlingson]

[oops, meant to Reply to the list but didn't! Sorry if you get this twice!]

2009/3/26 Голубев Анатолий <golubev at nordcomp.ru>:
> Hi, list! Can someone write a simple example or algorithm to
> programmatically add features to empty vector layer?

 Python or C++?

 Here's some python code from one of my plugins:

http://code.google.com/p/bsrplugins/source/browse/trunk/topocolour/adjlayer.py

 The 'make' function creates a new vector layer called 'vl' using the
'memory' provider. The layer has 'LineString' features (line 8). Each
feature has three attributes (lines 11-13).

 Then a loop adds some features using information from the 'ig' object
passed in.
  * construct a QgsGeometry object from some QPoint() objects
(QgsgeometryFromPolyline)
  * set the geometry of the feature (fet.setGeometry) and add the
attributes (fet.setAttributes).
  * add the feature to the layer provider (pr.addFeatures).

 Once that's done you may want to add the layer to the Qgis map registry.

 Translating this to C++ should be fairly simple. Hope this helps.

Barry