Add support for editing catalog cost in receiving batch, per new theme

had to add several "under the hood" features to make this work, to
embed a Vue component within grid `<td>` cells, etc.

tailbone/grids/core.py

@@ -68,11 +68,49 @@ class FieldList(list):
 class Grid(object):
     """
     Core grid class.  In sore need of documentation.
+
+    .. attribute:: raw_renderers
+
+       Dict of "raw" field renderers.  See also
+       :meth:`set_raw_renderer()`.
+
+       When present, these are rendered "as-is" into the grid
+       template, whereas the more typical scenario involves rendering
+       each field "into" a span element, like:
+
+       .. code-block:: html
+
+          <span v-html="RENDERED-FIELD"></span>
+
+       So instead of injecting into a span, any "raw" fields defined
+       via this dict, will be injected as-is, like:
+
+       .. code-block:: html
+
+          RENDERED-FIELD
+
+       Note that each raw renderer is called only once, and *without*
+       any arguments.  Likely the only use case for this, is to inject
+       a Vue component into the field.  A basic example::
+
+          from webhelpers2.html import HTML
+
+          def myrender():
+              return HTML.tag('my-component', **{'v-model': 'props.row.myfield'})
+
+          grid = Grid(
+              # ..normal constructor args here..
+
+              raw_renderers={
+                  'myfield': myrender,
+              },
+          )
     """
 
     def __init__(self, key, data, columns=None, width='auto', request=None,
                  model_class=None, model_title=None, model_title_plural=None,
                  enums={}, labels={}, assume_local_times=False, renderers={}, invisible=[],
+                 raw_renderers={},
                  extra_row_class=None, linked_columns=[], url='#',
                  joiners={}, filterable=False, filters={}, use_byte_string_filters=False,
                  searchable={},
@@ -109,6 +147,7 @@ class Grid(object):
         self.labels = labels or {}
         self.assume_local_times = assume_local_times
         self.renderers = self.make_default_renderers(renderers or {})
+        self.raw_renderers = raw_renderers or {}
         self.invisible = invisible or []
         self.extra_row_class = extra_row_class
         self.linked_columns = linked_columns or []
@@ -286,6 +325,21 @@ class Grid(object):
     def set_renderer(self, key, renderer):
         self.renderers[key] = renderer
 
+    def set_raw_renderer(self, key, renderer):
+        """
+        Set or remove the "raw" renderer for the given field.
+
+        See :attr:`raw_renderers` for more about these.
+
+        :param key: Field name.
+
+        :param renderer: Either a renderer callable, or ``None``.
+        """
+        if renderer:
+            self.raw_renderers[key] = renderer
+        else:
+            self.raw_renderers.pop(key, None)
+
     def set_type(self, key, type_):
         if type_ == 'boolean':
             self.set_renderer(key, self.render_boolean)
@@ -1313,7 +1367,10 @@ class Grid(object):
         # iterate over data rows
         for i in range(count):
             rowobj = raw_data[i]
-            row = {}
+
+            # nb. cache 0-based index on the row, in case client-side
+            # logic finds it useful
+            row = {'_index': i}
 
             # sometimes we need to include some "raw" data columns in our
             # result set, even though the column is not displayed as part of