Support ingesting zipped shapefile, geojson

If the payload's shape is a zipped shapefile or a geojson,
they will be parsed as shapes and added to the database. In
the case of geojson, the file is parsed and ingested directly.
In the case of zipped shapefiles, we save them to a temporary
directory, then load them via fiona and extract the shape from
within. fiona cannot read files from memory, and the uploaded
files could potentially be really heavy, so doing so helps
manage the load.

These are the only two formats we are supporting at the
moment, more may be added in the future.

This assumes a single Polygon input. Support for MultiPolygons
will be added in #127.

src/app/src/components/ModalSections/FileUpload.js

@@ -135,7 +135,7 @@ function UploadBox({ addFiles }) {
                     <Bold>ACCEPTED FILES</Bold>
                 </Text>
                 <Text color='gray.400'>
-                    <Bold>Shapefiles:</Bold> .SHP, .SHX and .DBF
+                    <Bold>Shapes:</Bold> Shapefile ZIP, GEOJSON
                     <br />
                     <Bold>Reference Images:</Bold> JPEG, PNG
                 </Text>

src/app/src/constants.js

@@ -86,7 +86,7 @@ export const ROLES = {
 
 export const REFERENCE_IMAGE_MIME_TYPES = ['image/png', 'image/jpeg'];
 export const REFERENCE_IMAGE_FILE_EXTENSIONS = ['.png', '.jpg', '.jpeg'];
-export const SHAPE_FILE_EXTENSIONS = ['.shp'];
+export const SHAPE_FILE_EXTENSIONS = ['.zip', '.geojson'];
 
 export const FILE_UPLOAD_ACCEPT_STRING = [
     ...REFERENCE_IMAGE_MIME_TYPES,

src/django/api/fields.py

@@ -1,9 +1,44 @@
-from rest_framework.fields import FileField
+import os
+import fiona
+import json
+import tempfile
 
-from django.contrib.gis.geos import Polygon
+from pathlib import Path
+from django.contrib.gis.geos import GEOSGeometry
+from rest_framework.fields import FileField
+from rest_framework.serializers import ValidationError
 
 
 class ShapefileField(FileField):
     def to_internal_value(self, data):
-        # shapefile = super().to_internal_value(data)
-        return Polygon()
+        if data.name.endswith(".zip"):
+            # Treat like a zipped shapefile
+            try:
+                tmpdir = tempfile.mkdtemp()
+                tmpfile = Path(f"{tmpdir}/{data.name}")
+                with open(tmpfile, "wb+") as f:
+                    for chunk in data.chunks():
+                        f.write(chunk)
+
+                with fiona.open(f"zip://{tmpfile}") as f:
+                    # TODO Capture all features in the shapefile, not just first
+                    geojson = json.dumps(f[0]["geometry"])
+                    return GEOSGeometry(geojson)
+
+            except Exception:
+                raise ValidationError(
+                    f"Could not parse {data.name} as a zipped shapefile."
+                )
+
+            finally:
+                os.remove(tmpfile)
+                os.rmdir(tmpdir)
+
+        if data.name.endswith(".geojson"):
+            geojson = data.read()
+            return GEOSGeometry(geojson)
+
+        raise ValidationError(
+            f"Incompatible file: {data.name}."
+            " Must be either a zipped shapefile, or a geojson."
+        )