Let config override the CORE API client factory

rattail_corepos/app.py

@@ -104,3 +104,23 @@ class CoreHandler(GenericHandler):
             office_url = self.get_office_url(require=require)
         if office_url:
             return f'{office_url}/item/vendors/VendorIndexPage.php?vid={id}'
+
+    def make_webapi(self):
+        """
+        Make and return a new CORE-POS API client object.
+        """
+
+        spec = self.config.get('corepos.api', 'factory',
+                               default='corepos.api:CoreWebAPI')
+        factory = self.app.load_object(spec)
+
+        url = self.config.require('corepos.api', 'url')
+
+        kwargs = {}
+        username = self.config.get('corepos.api', 'htdigest.username')
+        password = self.config.get('corepos.api', 'htdigest.password')
+        if username and password:
+            kwargs['htdigest_username'] = username
+            kwargs['htdigest_password'] = password
+
+        return factory(url, **kwargs)

rattail_corepos/corepos/api.py

@@ -24,22 +24,14 @@
 CORE-POS API
 """
 
-from requests.auth import HTTPDigestAuth
+import warnings
-
-from corepos.api import CoreWebAPI
 
 
 def make_corepos_api(config):
-    """
+    """ DEPRECATED """
-    Make and return a new CORE-POS API client object.
+    warnings.warn("make_corepos_api() function is deprecated; please use "
-    """
+                  "app.get_corepos_handler().make_webapi() instead",
-    url = config.require('corepos.api', 'url')
+                  DeprecationWarning, stacklevel=2)
 
-    kwargs = {}
+    app = config.get_app()
-    username = config.get('corepos.api', 'htdigest.username')
+    return app.get_corepos_handler().make_webapi()
-    password = config.get('corepos.api', 'htdigest.password')
-    if username and password:
-        kwargs['htdigest_username'] = username
-        kwargs['htdigest_password'] = password
-
-    return CoreWebAPI(url, **kwargs)