add ability to filter by start_date

setup.py

@@ -2,7 +2,7 @@
 from setuptools import setup, find_packages
 
 setup(name="tap-xero",
-      version="2.2.11",
+      version="2.2.12",
       description="Singer.io tap for extracting data from the Xero API",
       author="Stitch",
       url="http://singer.io",

tap_xero/client.py

@@ -246,6 +246,8 @@ def filter(self, tap_stream_id, since=None, **params):
         headers = {"Accept": "application/json",
                    "Authorization": "Bearer " + self.access_token,
                    "Xero-tenant-id": self.tenant_id}
+        if params.get("headers"):
+            headers.update(params.pop("headers"))
         if self.user_agent:
             headers["User-Agent"] = self.user_agent
         if since:

tap_xero/streams.py

@@ -184,6 +184,10 @@ def sync(self, ctx):
         journal_number = ctx.get_bookmark(bookmark) or 0
         while True:
             filter_options = {"offset": journal_number}
+            if ctx.config.get("start_date"):
+                start_date = parse(ctx.config.get("start_date"))
+                filter_options['headers'] = {"If-Modified-Since": start_date.strftime("%Y-%m-%dT%H:%M:%SZ")}
+
             records = _make_request(ctx, self.tap_stream_id, filter_options)
             logging.info("Got {} records: {}".format(
                 len(records), records