initial geojson provider

pygeoapi/provider/__init__.py

@@ -30,7 +30,8 @@
 import importlib
 
 PROVIDERS = {
-    'Elasticsearch': 'pygeoapi.provider.elasticsearch.ElasticsearchProvider'
+    'Elasticsearch': 'pygeoapi.provider.elasticsearch.ElasticsearchProvider',
+    'GeoJSON': 'pygeoapi.provider.geojson.GeoJSONProvider'
 }
 
 

pygeoapi/provider/geojson.py

@@ -0,0 +1,105 @@
+# =================================================================
+#
+# Authors: Tom Kralidis <tomkralidis@gmail.com>
+#
+# Copyright (c) 2018 Tom Kralidis
+#
+# Permission is hereby granted, free of charge, to any person
+# obtaining a copy of this software and associated documentation
+# files (the "Software"), to deal in the Software without
+# restriction, including without limitation the rights to use,
+# copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the
+# Software is furnished to do so, subject to the following
+# conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+# OTHER DEALINGS IN THE SOFTWARE.
+#
+# =================================================================
+
+import os
+import json
+
+from pygeoapi.provider.base import BaseProvider
+
+
+EMPTY_COLLECTION = {
+    'type': 'FeatureCollection',
+    'features': []
+}
+
+
+class GeoJSONProvider(BaseProvider):
+    """Provider class backed by local GeoJSON files
+
+    This is meant to be simple
+    (no external services, no schema)
+
+    at the expense of performance
+    (no indexing, full serialization roundtrip on each request)
+    """
+
+    def __init__(self, definition):
+        """initializer"""
+
+        BaseProvider.__init__(self, definition)
+
+        # url is a file path, TODO use urlparse or support local paths
+        self.path = self.url.replace("file://", '')
+        self._validate_or_create(self.path)
+
+    @classmethod
+    def _validate_or_create(self, path):
+        """Validate that the path exists and that
+        it is a geojson feature collection
+        """
+        if os.path.exists(path):
+            with open(path) as src:
+                data = json.loads(src.read())
+                assert data['type'] == 'FeatureCollection'
+        else:
+            with open(path, 'w') as dst:
+                dst.write(json.dumps(EMPTY_COLLECTION))
+
+    def _load(self):
+        with open(self.path) as src:
+            data = json.loads(src.read())
+        return data
+
+    def query(self):
+        """
+        query the provider
+
+        :returns: FeatureCollection dict of 0..n GeoJSON features
+        TODO yield GeoJSON features
+        """
+        return self._load()
+
+    def get(self, identifier):
+        """
+        query the provider by id
+
+        :param identifier: feature id
+        :returns: dict of single GeoJSON feature
+        """
+        collection = EMPTY_COLLECTION.copy()
+
+        all_data = self._load()
+        for feature in all_data['features']:
+            if feature[self.id_field]:
+                collection['features'].append(feature)
+
+        return collection
+
+    def __repr__(self):
+        return '<GeoJSONProvider> {}'.format(self.url)