Reproduced from the review comment. A `group` element carrying minWidth
generated:
if width >= 64: # breakpoint: 64px+ displays only
# <nothing>
manager.py.j2 wraps each element in the breakpoint and blink blocks, but the
body comes from the per-type branches -- and a type with no branch contributes
nothing, so the wrapper opens a block with no statements. ast.parse then fails
and the caller is told only "Generated code has a syntax error: expected an
indented block ... line 49", naming a line of generated source they never see.
Two defences:
- _preprocess_elements drops types the template has no branch for, alongside
the existing `section` skip. This is the root cause: those elements should
never have reached the template.
- The branch chain ends in `{% else %}pass`, so a type added to the canvas
before its drawing branch exists degrades to a no-op rather than a plugin
that will not parse.
The review also cited dynamic_text with binding_source != 'config'. That one
does not reproduce -- the branch emits a draw_text regardless -- which is why
an earlier attempt to reproduce this found nothing.
_RENDERABLE_ELEMENT_TYPES has to stay in step with the template: a type listed
with no branch emits an empty block again, and a branch missing from the list
is silently dropped from every generated plugin. A test asserts the two sets
are equal rather than trusting them to be maintained together.
Tests: 12 new, covering group/unknown/section against breakpoint, blink and
both nested, plus the set-equality and fallback checks. 7 fail with both
defences reverted. 172 composer tests pass; full suite 3862 passed, the one
failure being test_install_lowmem (pre-existing, awaiting #492).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01STMbQE4YctTacQXfbYqKuW
Web UI (/composer/) for building a working LEDMatrix plugin without
writing Python: drop elements (text, time, date, countdown, scrolling
text, bar/waveform, groups, custom config variables) onto a canvas
matching the real panel's pixel grid, configure them with live preview,
then generate a real plugin (manager.py + manifest.json + config_schema.json)
from manager.py.j2 -- downloadable as a ZIP or installed directly.
NOTE: composer_bp is not yet registered in web_interface/app.py, so this
blueprint is currently inert. Split out of the original chore/dead-code-
removal commit, which had accidentally bundled this in alongside unrelated
dead-code deletions; app.py registration was not part of that commit
either and still needs to be added before this is reachable.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KEZK1P1Q1fu5pcuVrkrCFZ
