[QGIS-Developer] Export layer with measures

[Radim Blazek]

On Mon, May 29, 2017 at 1:56 PM, Nyall Dawson <nyall.dawson at gmail.com> wrote:
> On 29 May 2017 at 21:35, Radim Blazek <radim.blazek at gmail.com> wrote:
>> Hi,
>>
>> I need to export a vector layer with measures (LineStringM) to
>> Shapefile and PostGIS in QGIS3, neither works.
>>
>> Shapefile: there is only 'include z dimension' but no 'include m
>> dimension' and no PolylineM in SHPT options in save as dialog. The
>> layer is exported without M.
>
> What GDAL version? You need GDAL >= 2.1 for M values in shapefiles to
> work. I think if you've got a source layer with m values and save to
> shp with GDAL 2.1 it should just work.

GDAL 2.1.3.

I have created a memory layer with type LineStringM, which has correct
wkbType, QgsWkbTypes.hasM(layer.wkbType()) is true. M is correct in
identify - derived attributes.

BTW: wkbType in layer properties would be useful.

Radim

> That checkbox for "include z
> dimension" will add z dimension to an existing 2d layer, but it
> shouldn't be required if your layer already has a z dimension.
>
> We probably should add a "include m values" option as well (if
> supported gdal version is present) for consistency.
>
> Nyall