activerecord_postgis_adapter: undefined method `point' for nil:NilClass

问题

Problem

90% sure it's a setup error on my end, but I can't do self.factory and trying to access lonlat gives me an exception "undefined method `point' for nil:NilClass"

I can

Set lonlat using:

mfactory = RGeo::ActiveRecord::SpatialFactoryStore.instance.factory(:geo_type => 'point')
self.lonlat = mfactory.point(long, lat)
self.save

This gives me values like 0101000020E610000061C3D32B65965DC03657CD7344F64040 in the db.

I can't use:

self.lonlat = "POINT(#{long},#{lat})"
self.save

Questions

Do I need to setup something specific in the model?

回答1:

I created a github issue with a less consise but more detailed explaination.

RGeos depends on GEOS. This error is a result of RGeos not being able to load GEOS.

To check if this is the issue:

$ rails c
> RGeo::Geos.supported?
=> false

To check if you have GEOS installed:

geos-config --version

If GEOS isn't installed:

brew install geos

If GEOS is installed, fix your installed RGeo:

$ geos-config --prefix
/usr/local/Cellar/geos/3.5.0
$ gem install rgeo -- --with-geos-dir=/usr/local/Cellar/geos/3.5.0

Should now be installed correctly and your errors fixed. You can check as we did above:

$ rails c
> RGeo::Geos.supported?
=> true

If this doesn't work uninstall ALL versions of geos and rgeo:

$ brew uninstall geos
$ gem uninstall rgeo

Re-install geos and rgeo as instructed above. You should have gem 'rgeo' in your Gemfile and after you bundle, you should see this as one of the outputs: "Installing rgeo 0.4.0 with native extensions"

来源：https://stackoverflow.com/questions/31170055/activerecord-postgis-adapter-undefined-method-point-for-nilnilclass