{# Rule source switch and List preview of a rule with a list source
(ListSourceViewMixin in application/modules/rule/list_source_views.py).
* The "Rule source" select decides which step 2 section is shown: the host
Conditions, or the Pasted List. Static Rule is hidden for a list rule,
which is always host-independent.
* The pasted text and the outcome templates go to the view's
`_list_source_preview` endpoint, which parses them exactly like the
export does. The answer is shown below the field: separator, the column
variables (click one to insert it into the outcome field last edited),
the first rows, errors and variables that are no column.
* A view with a `list_rule_debug` page gets it linked in the help.
Cell content is only ever inserted as text. #}