Set world bounding box on GeoServer layer if DB table is empty

Fix #40

Related to #159

doc/rest.md

@@ -70,6 +70,7 @@ Body parameters:
       - ShapeFile files (at least three files: .shp, .shx, .dbf)
       - file names, i.e. array of strings
    - if file names are provided, files must be uploaded subsequently using [POST Layer Chunk](#post-layer-chunk)
+   - if published file has empty bounding box (i.e. no features), its bounding box on WMS/WFS endpoint is set to the whole World
 - *name*, string
    - computer-friendly identifier of the layer
    - must be unique among all layers of one workspace
@@ -178,6 +179,7 @@ Body parameters:
       - ShapeFile files (at least three files: .shp, .shx, .dbf)
       - file names, i.e. array of strings
    - if file names are provided, files must be uploaded subsequently using [POST Layer Chunk](#post-layer-chunk)
+   - if published file has empty bounding box (i.e. no features), its bounding box on WMS/WFS endpoint is set to the whole World
 - *title*
 - *description*
 - *crs*, string `EPSG:3857` or `EPSG:4326`

sample/layman.layer/empty.prj

@@ -0,0 +1 @@
+GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137,298.257223563]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]

sample/layman.layer/empty.qpj

@@ -0,0 +1 @@
+GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]]

sample/layman.layer/single_point.prj

@@ -0,0 +1 @@
+GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137,298.257223563]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]

sample/layman.layer/single_point.qpj

@@ -0,0 +1 @@
+GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]]

src/layman/layer/db/__init__.py

@@ -1,4 +1,5 @@
 from collections import defaultdict
+import json
 import math
 import os
 import psycopg2
@@ -523,3 +524,34 @@ def ensure_attributes(attribute_tuples):
     if missing_attributes:
         create_string_attributes(missing_attributes, conn_cur)
     return missing_attributes
+
+
+def get_bbox(username, layername, conn_cur=None):
+    conn, cur = conn_cur or get_connection_cursor()
+
+    try:
+        cur.execute(f"""
+select ST_AsGeoJSON(ST_Extent(wkb_geometry))
+from {username}.{layername}
+""")
+    except BaseException:
+        raise LaymanError(7)
+    rows = cur.fetchall()
+    result = rows[0][0]
+    if result is not None:
+        result = json.loads(result)
+    if isinstance(result, dict):
+        if result['type'] == 'Point':
+            result = result['coordinates'] + result['coordinates']
+        elif result['type'] == 'Polygon':
+            result = [
+                min([c[0] for c in result['coordinates']]),
+                min([c[1] for c in result['coordinates']]),
+                max([c[0] for c in result['coordinates']]),
+                max([c[1] for c in result['coordinates']]),
+            ]
+        else:
+            raise Exception(f"Unknown BBox type {result['type']}")
+    elif result is not None:
+        raise Exception(f"Unknown BBox result {result}")
+    return result

src/layman/layer/db/db_test.py

@@ -124,6 +124,26 @@ def populated_places_table(testuser1):
     delete_layer(username, layername)
 
 
+@pytest.fixture()
+def empty_table(testuser1):
+    file_path = 'sample/layman.layer/empty.shp'
+    username = testuser1
+    layername = 'empty'
+    db.import_layer_vector_file(username, layername, file_path, None)
+    yield username, layername
+    delete_layer(username, layername)
+
+
+@pytest.fixture()
+def single_point_table(testuser1):
+    file_path = 'sample/layman.layer/single_point.shp'
+    username = testuser1
+    layername = 'single_point'
+    db.import_layer_vector_file(username, layername, file_path, None)
+    yield username, layername
+    delete_layer(username, layername)
+
+
 def test_abort_import_layer_vector_file(client):
     username = 'testuser1'
     layername = 'ne_10m_admin_0_countries'
@@ -269,3 +289,15 @@ def test_get_most_frequent_lower_distance(client, country110m_table, country50m_
     sd_5k = db.guess_scale_denominator(username, layername_5k)
     assert 1000 <= sd_5k <= 25000
     assert sd_5k == 5000
+
+
+def test_empty_table_bbox(client, empty_table):
+    username, layername = empty_table
+    bbox = db.get_bbox(username, layername)
+    assert bbox is None
+
+
+def test_single_point_table_bbox(client, single_point_table):
+    username, layername = single_point_table
+    bbox = db.get_bbox(username, layername)
+    assert bbox[0] == bbox[2] and bbox[1] == bbox[3], bbox

src/layman/layer/empty_bbox_test.py

@@ -0,0 +1,79 @@
+import os
+import pytest
+import requests
+from owslib.wms import WebMapService
+from layman import settings
+from layman.layer.geoserver import wms as gs_wms
+from test import process, process_client
+from test.data import wfs as wfs_data_util
+
+
+def get_shp_file_paths(shp_file_path):
+    extensions = ['dbf', 'prj', 'qpj', 'shx']
+    root, shp_ext = os.path.splitext(shp_file_path)
+    result = [f"{root}.{ext}" for ext in extensions]
+    result.append(shp_file_path)
+    return result
+
+
+def assert_non_empty_bbox(bbox):
+    assert bbox[0] < bbox[2] and bbox[1] < bbox[3]
+
+
+def assert_wms_layer(workspace, layername, exp_title):
+    wms = WebMapService(gs_wms.get_wms_url(workspace), gs_wms.VERSION)
+    assert layername in wms.contents
+    wms_layer = wms[layername]
+    assert wms_layer.title == exp_title
+    assert_non_empty_bbox(wms_layer.boundingBox)
+    assert_non_empty_bbox(wms_layer.boundingBoxWGS84)
+    return wms_layer
+
+
+def wfs_t_insert_point(workspace, layername):
+    wfs_t_data = wfs_data_util.get_wfs20_insert_points(workspace, layername)
+    wfs_t_url = f"http://{settings.LAYMAN_SERVER_NAME}/geoserver/{workspace}/wfs?request=Transaction"
+    wfs_t_headers = {
+        'Accept': 'text/xml',
+        'Content-type': 'text/xml',
+    }
+    r = requests.post(wfs_t_url,
+                      data=wfs_t_data,
+                      headers=wfs_t_headers)
+    assert r.status_code == 200
+
+
+@pytest.fixture(scope="module")
+def ensure_layman():
+    layman_process = process.start_layman()
+    yield
+    process.stop_process(layman_process)
+
+
+@pytest.mark.parametrize('layername, file_paths', [
+    ('empty', get_shp_file_paths('sample/layman.layer/empty.shp')),
+    ('single_point', get_shp_file_paths('sample/layman.layer/single_point.shp')),
+])
+@pytest.mark.usefixtures('ensure_layman')
+def test_empty_shapefile(layername, file_paths):
+    workspace = 'test_empty_bbox_workspace'
+    title = layername
+
+    process_client.publish_layer(workspace, layername, file_paths=file_paths)
+
+    wms_layer = assert_wms_layer(workspace, layername, title)
+    native_bbox = wms_layer.boundingBox
+    wgs_bbox = wms_layer.boundingBoxWGS84
+
+    title = 'new title'
+    process_client.patch_layer(workspace, layername, title=title)
+    wms_layer = assert_wms_layer(workspace, layername, title)
+    assert wms_layer.boundingBox == native_bbox
+    assert wms_layer.boundingBoxWGS84 == wgs_bbox
+
+    wfs_t_insert_point(workspace, layername)
+    wms_layer = assert_wms_layer(workspace, layername, title)
+    assert wms_layer.boundingBox == native_bbox
+    assert wms_layer.boundingBoxWGS84 == wgs_bbox
+
+    process_client.delete_layer(workspace, layername)

src/layman/layer/geoserver/__init__.py

@@ -8,6 +8,7 @@
 from layman.http import LaymanError
 from layman import settings
 from layman.common import geoserver as common
+from layman.layer import db as db_source
 
 FLASK_WORKSPACES_KEY = f"{__name__}:WORKSPACES"
 FLASK_RULES_KEY = f"{__name__}:RULES"
@@ -64,28 +65,38 @@ def publish_layer_from_db(username, layername, description, title):
         title
     ]
     keywords = list(set(keywords))
+    feature_type_def = {
+        "name": layername,
+        "title": title,
+        "abstract": description,
+        "keywords": {
+            "string": keywords
+        },
+        "srs": "EPSG:3857",
+        "projectionPolicy": "FORCE_DECLARED",
+        "enabled": True,
+        "store": {
+            "@class": "dataStore",
+            "name": username + ":postgresql",
+        },
+    }
+    db_bbox = db_source.get_bbox(username, layername)
+    if db_bbox is None:
+        # world
+        native_bbox = {
+            "minx": -20026376.39,
+            "miny": -20048966.10,
+            "maxx": 20026376.39,
+            "maxy": 20048966.10,
+            "crs": "EPSG:3857",
+        }
+        feature_type_def['nativeBoundingBox'] = native_bbox
     r = requests.post(
         urljoin(settings.LAYMAN_GS_REST_WORKSPACES,
                 username + '/datastores/postgresql/featuretypes/'),
-        data=json.dumps(
-            {
-                "featureType": {
-                    "name": layername,
-                    "title": title,
-                    "abstract": description,
-                    "keywords": {
-                        "string": keywords
-                    },
-                    "srs": "EPSG:3857",
-                    "projectionPolicy": "FORCE_DECLARED",
-                    "enabled": True,
-                    "store": {
-                        "@class": "dataStore",
-                        "name": username + ":postgresql",
-                    },
-                }
-            }
-        ),
+        data=json.dumps({
+            "featureType": feature_type_def
+        }),
         headers=headers_json,
         auth=settings.LAYMAN_GS_AUTH
     )