Add CYLC_ variables to Jinja2 globals.

cylc · Jun 19, 2023 · 546cc73 · 546cc73
1 parent 231f0ea
commit 546cc73
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Showing 2 changed files with 32 additions and 17 deletions.
diff --git a/cylc/flow/parsec/jinja2support.py b/cylc/flow/parsec/jinja2support.py
@@ -186,11 +186,17 @@ def jinja2environment(dir_=None):
                     envnsp[fname] = getattr(module, fname)
 
     # Import WORKFLOW HOST USER ENVIRONMENT into template:
-    # (usage e.g.: {{environ['HOME']}}).
+    # (Usage e.g.: {{environ['HOME']}}).
     env.globals['environ'] = os.environ
+
     env.globals['raise'] = raise_helper
     env.globals['assert'] = assert_helper
 
+    # And all `CYLC_` variables (this will include CYLC_WORKFLOW environment
+    # variables exported by `cylc` commands before config file parsing.
+    for key, val in os.environ.items():
+        if key.startswith('CYLC_'):
+            env.globals[key] = val
     return env
 
 

diff --git a/cylc/flow/scripts/view.py b/cylc/flow/scripts/view.py
@@ -18,11 +18,16 @@
 
 """cylc view [OPTIONS] ARGS
 
-Print a processed workflow configuration.
+Print workflow configurations as processed before full parsing by Cylc. This
+includes Jinja2 or Empy template processing, and inlining of include-files.
+Some explanatory markup may also be requested.
+
+Warning: this command will fail if Jinja2 `CYLC_` variables are referenced
+without default values, because they are only defined during full parsing.
+E.g., `{{CYLC_WORKFLOW_NAME | default("not defined")}}`.
+
+See also `cylc config`, which displays the fully parsed configuration.
 
-Note:
-  This is different to `cylc config` which displays the parsed
-  configuration (as Cylc would see it).
 """
 
 import asyncio
@@ -116,20 +121,24 @@ async def _main(options: 'Values', workflow_id: str) -> None:
     )
 
     # read in the flow.cylc file
-    viewcfg = {
-        'mark': options.mark,
-        'single': options.single,
-        'label': options.label,
-        'empy': options.empy or options.process,
-        'jinja2': options.jinja2 or options.process,
-        'contin': options.cat or options.process,
-        'inline': (options.inline or options.jinja2 or options.empy
-                   or options.process),
-    }
     for line in read_and_proc(
         flow_file,
-        load_template_vars(options.templatevars, options.templatevars_file),
-        viewcfg=viewcfg,
+        load_template_vars(
+            options.templatevars,
+            options.templatevars_file
+        ),
+        viewcfg={
+            'mark': options.mark,
+            'single': options.single,
+            'label': options.label,
+            'empy': options.empy or options.process,
+            'jinja2': options.jinja2 or options.process,
+            'contin': options.cat or options.process,
+            'inline': (
+                options.jinja2 or options.empy or
+                options.inline or options.process
+            ),
+        },
         opts=options,
     ):
         print(line)