(subplot.md): Add scenario about not needing a template for docgen

Signed-off-by: Daniel Silverstone <dsilvers@digital-scurf.org>

1 files changed, 34 insertions, 0 deletions

diff --git a/subplot.md b/subplot.md
index 27da981..2d494b3 100644
--- a/subplot.md
+++ b/subplot.md
@@ -1123,6 +1123,40 @@ But there are no scenarios in this file, and thus nothing can be generated in a
 
 ~~~
 
+## No template means you can docgen but not codegen
+
+When running `docgen` you do not **need** a template to have been defined in the
+subplot input document.  If you have template-specific bindings then you **should**
+provide one, but if not, then it is unnecessary.  This means you can use `docgen`
+to build documents before you have any inkling of the implementation language
+necessary to validate the scenarios.
+
+~~~scenario
+given file notemplate.subplot
+given file notemplate.md
+and an installed subplot
+when I run subplot docgen notemplate.subplot -o notemplate.html
+then file notemplate.html exists
+when I try to run subplot codegen notemplate.subplot -o test.py
+then command fails
+and stderr contains "document has no template"
+~~~
+
+~~~{#notemplate.subplot .file .yaml .numberLines}
+title: No templates in here
+markdowns: [notemplate.md]
+impls: { }
+~~~
+
+~~~{#notemplate.md .file .markdown .numberLines}
+# This is a title
+
+```scenario
+then failure ensues
+```
+
+~~~
+
 ## Keywords
 
 Subplot supports the keywords **given**, **when**, and **then**, and