[Qgis-developer] Cleanly create memory layer in Python?

[Ricardo Filipe Soares Garcia da]

Hi Chris

In the 'Profile from lines' plugin I'm using a similar approach:

# python code
projectionSettingKey = "Projections/defaultBehaviour"
oldProjectionSetting = self.qgisSettings.value(projectionSettingKey)
self.qgisSettings.setValue(projectionSettingKey, "useGlobal")
self.qgisSettings.sync()
pointLayer = QgsVectorLayer("Point", "temporary_points", "memory")
pointLayer.setCrs(linesLayer.crs())
self.qgisSettings.setValue(projectionSettingKey, oldProjectionSetting)

This was discussed a while back at another thread in this mailing-list
(08/09/2010) and this was a suggestion from Martin Dobias. It seems at
the moment it is as clean as it gets (its still a bit unclean though
;))

I'd also be interested in knowing alternative ways to do this.


On Thu, Jan 6, 2011 at 8:16 PM, Chris Crook <ccrook at linz.govt.nz> wrote:
> Hi All
>
> I'm wanting to create a memory provider in Python without invoking the CRS selection dialog (even if the QGIS settings are set to "Prompt for CRS when a new layer is created".
>
> At the moment my code looks like:
>
>        settings = QSettings()
>        prjSetting = settings.value("/Projections/defaultBehaviour")
>        settings.setValue("/Projections/defaultBehaviour", QVariant(""))
>        layer = QgsVectorLayer("point",name,"memory")
>        if prjSetting:
>            settings.setValue("/Projections/defaultBehaviour",prjSetting)
>
> This does work, but it seems a bit cumbersome (at first glance it doesn't even look like creating a vector layer!), so I'm wondering if there is a cleaner approach..
>
> Cheers
> Chris
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-- 
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Ricardo Garcia Silva