The Autofields plugin for QGis allows filling
the attribute fields of a layer
creating or publishing entities.
You can, for example, fill a
field with the value of x or y of the point, or the beginning point of a
segment, the segment length, etc. You can use this plugin from version
2.12 of QGis and only from version 2.14 if you
the calculations based on the geometry requiring coordinate system
If you find this
plugin useful, I suggest you visiting the page of its creator http://geotux.tuxfamily.org/index.php/en/component/k2/item/333-autofields-plugin-for-qgis
, German Carrillo, and make a small donation to ensure the sustainability of
the development and the portage on future versions of QGis.