Add CONTRIBUTING.md

CONTRIBUTING.md

@@ -0,0 +1,51 @@
Contributing guidelines
=======================

Guidelines:

1. Approximately adhere to [Orange's contributing guidelines].

[Orange's contributing guidelines]: https://github.com/biolab/orange3/blob/master/CONTRIBUTING.md


Building missing GeoJSON files
------------------------------

Due to its size, GeoJSON files aren't tracked in the same repository branch.
Built JSONs can be found in _json_ branch. You can merge the files into your
current development branch with:

    git checkout topic-branch
    git checkout json orangecontrib/geo/geojson/*.json
    git reset HEAD orangecontrib/geo/geojson/*.json

When re-building the JSON files due to upstream region shape changes, the 
following should work:

    git checkout master
    git branch -D json
    git checkout --orphan json
    git reset HEAD .

    cd orangecontrib/geo/geojson
    ./make-geojson.sh

    git add admin*.json
    git commit -m "Add binary GeoJSON files"

    # force-push to overwrite remote binary json branch
    git push --force

When building the source distribution package, the following workflow 
works for me:

    git checkout master
    git checkout -b build
    git checkout json orangecontrib/geo/geojson/*.json
    git reset HEAD .

    python setup.py sdist
    # ... upload built tgz

    git checkout --force master
    git branch -D build

README.md

@@ -4,3 +4,11 @@ Orange3-Geo
[Orange] add-on for dealing with geography and geo-location.

[Orange]: http://orange.biolab.si


Installing
----------
Installing from source requires merging GeoJSON files from _json_ branch.
See [CONTRIBUTING] for more info.

[CONTRIBUTING]: ./CONTRIBUTING.md

orangecontrib/geo/mapper.py

@@ -37,7 +37,14 @@ def _admin_cc(filename):
    cc_shapes = {}
    id_regions = {}
    us_states = {}
    for filename in glob(path.join(GEOJSON_DIR, 'admin*.json')):

    files = glob(path.join(GEOJSON_DIR, 'admin*.json'))
    if not files:
        raise RuntimeError('Missing GeoJSON files. '
                           'In development environments, merge in the "json" '
                           'branch. See CONTRIBUTING.md')

    for filename in files:
        admin, cc = _admin_cc(filename)

        with open(filename) as f: