Adding pre/post handler support

core/registrar/config-schema.yaml

@@ -62,6 +62,35 @@ properties:
         kwargs:
           description: Constructor keyword arguments
           type: object
-
-  # TODO: describe type specific args/kwargs
-
+    pre_handlers:
+      description: List of handlers to be run prior the registration of an item.
+      type: array
+      items:
+        description: A single pre-registration handler
+        type: object
+        properties:
+          path:
+            description: Python module path to the registration handler
+            type: string
+          args:
+            description: arguments for the initialization of the handler
+            type: array
+          kwargs:
+            description: keyword arguments for the initialization of the handler
+            type: object
+    post_handlers:
+      description: List of handlers to be run prior the registration of an item.
+      type: array
+      items:
+        description: A single pre-registration handler
+        type: object
+        properties:
+          path:
+            description: Python module path to the registration handler
+            type: string
+          args:
+            description: arguments for the initialization of the handler
+            type: array
+          kwargs:
+            description: keyword arguments for the initialization of the handler
+            type: object

core/registrar/post_handlers.py

+import os.path
+import textwrap
+from datetime import datetime
+
+from .context import Context
+from .utils import isoformat
+from .xml import escape
+
+
+class ReportingPostHandler:
+    def __init__(self, service_url: str, reporting_dir: str):
+        self.service_url = service_url
+        self.reporting_dir = reporting_dir
+
+    def __call__(self, config: dict, path: str, context: Context):
+        inserted = datetime.now()
+        timestamp = inserted.strftime("%Y%m%dT%H%M%S")
+        with open(os.path.join(self.reporting_dir, 'item_%s_%s.xml' % (timestamp, context.identifier)), 'w') as f:
+            f.write(textwrap.dedent("""
+                <?xml version="1.0" encoding="UTF-8"?>
+                <DataAccessItemt
+                    xsi:schemaLocation="http://www.telespazio.com/CSCDA/CDD/PDAS PDAS_interfaces%2020190924_1916.xsd"
+                    xmlns="http://www.telespazio.com/CSCDA/CDD/PDAS"
+                    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+                  <identifier>{identifier}</identifier>
+                  <BROWSE_AVAILABILITY_DATETIME>{availability_time}</BROWSE_AVAILABILITY_DATETIME>
+                  <URL>
+                      <Service>WCS</Service>
+                      <URL>{wms_capabilities_url}</URL>
+                  </URL>
+                  <URL>
+                      <Service>WMS</Service>
+                      <URL>{wcs_capabilities_url}</URL>
+                  </URL>
+                </DataAccessItem>
+            """.format(
+                identifier=escape(context.identifier),
+                availability_time=escape(isoformat(inserted)),
+                wcs_capabilities_url=escape(
+                    '%s/ows?service=wcs&request=GetCapabilities&cql=identifier="%s"'
+                    % (self.service_url, context.identifier)
+                ),
+                wms_capabilities_url=escape(
+                    '%s/ows?service=wms&request=GetCapabilities&cql=identifier="%s"'
+                    % (self.service_url, context.identifier)
+                ),
+            )))

core/registrar/registrar.py

 import re
 import logging
+import importlib
 
 from .source import get_source
 from .scheme import get_scheme
@@ -39,8 +40,24 @@ def register_file(config: dict, path: str, replace: bool=False):
     return context
 
 
+def _get_handlers(config, name):
+    handlers = []
+    for handler_def in config.get(name, []):
+        module_path, handler_name = handler_def['path'].rpartition('.')
+        handler_cls = getattr(importlib.import_module(module_path), handler_name)
+        handlers.append(
+            handler_cls(
+                *handler_def.get('args', []),
+                **handler_def.get('kwargs', []),
+            )
+        )
+
+    return handlers
+
+
 def get_pre_handlers(config):
-    return []
+    return _get_handlers(config, 'pre_handlers')
+
 
 def get_post_handlers(config):
-    return []
+    return _get_handlers(config, 'post_handlers')

core/registrar/utils.py

+def isoformat(dt):
+    """ Formats a datetime object to an ISO string. Timezone naive datetimes are
+        are treated as UTC Zulu. UTC Zulu is expressed with the proper "Z"
+        ending and not with the "+00:00" offset declaration.
+
+        :param dt: the :class:`datetime.datetime` to encode
+        :returns: an encoded string
+    """
+    if not dt.utcoffset():
+        dt = dt.replace(tzinfo=None)
+        return dt.isoformat("T") + "Z"
+    return dt.isoformat("T")

core/registrar/xml.py

@@ -4,6 +4,7 @@ from tempfile import gettempdir, gettempprefix
 from dataclasses import dataclass, field
 from typing import Union, Type, Optional, List, Callable, Any
 import logging
+from xml.sax.saxutils import escape
 
 import lxml.etree