Expose config for identifying supported vendors

unfortunately must identify vendors at each app node separately, but
this is definitely still an improvement..

tailbone/views/vendors/core.py

@@ -33,6 +33,7 @@ from rattail.db import model
 from webhelpers2.html import tags
 
 from tailbone.views import MasterView
+from tailbone.db import Session
 
 
 class VendorView(MasterView):
@@ -179,6 +180,62 @@ class VendorView(MasterView):
              'type': bool},
         ]
 
+    def configure_get_context(self, **kwargs):
+        context = super(VendorView, self).configure_get_context(**kwargs)
+
+        context['supported_vendor_settings'] = self.configure_get_supported_vendor_settings()
+
+        return context
+
+    def configure_gather_settings(self, data, **kwargs):
+        settings = super(VendorView, self).configure_gather_settings(
+            data, **kwargs)
+
+        supported_vendor_settings = self.configure_get_supported_vendor_settings()
+        for setting in six.itervalues(supported_vendor_settings):
+            name = 'rattail.vendor.{}'.format(setting['key'])
+            settings.append({'name': name,
+                             'value': data[name]})
+
+        return settings
+
+    def configure_remove_settings(self, **kwargs):
+        super(VendorView, self).configure_remove_settings(**kwargs)
+
+        model = self.model
+        names = []
+
+        supported_vendor_settings = self.configure_get_supported_vendor_settings()
+        for setting in six.itervalues(supported_vendor_settings):
+            names.append('rattail.vendor.{}'.format(setting['key']))
+
+        if names:
+            # nb. we do not use self.Session b/c that may not point to
+            # the Rattail DB for the subclass
+            Session().query(model.Setting)\
+                     .filter(model.Setting.name.in_(names))\
+                     .delete(synchronize_session=False)
+
+    def configure_get_supported_vendor_settings(self):
+        app = self.get_rattail_app()
+        vendor_handler = app.get_vendor_handler()
+        batch_handler = app.get_batch_handler('purchase')
+        settings = {}
+
+        for parser in batch_handler.get_supported_invoice_parsers():
+            key = parser.vendor_key
+            if not key:
+                continue
+
+            vendor = vendor_handler.get_vendor(self.Session(), key)
+            settings[key] = {
+                'key': key,
+                'value': vendor.uuid if vendor else None,
+                'label': six.text_type(vendor) if vendor else None,
+            }
+
+        return settings
+
 
 def defaults(config, **kwargs):
     base = globals()