fix(widgets): ColumnChart runtime JSON.parse error — unset chart-series String emitted as \" \" - #5
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…time JSON.parse)
A ColumnChart with a static series passed mx check but failed to render with a
client-side JSON.parse('Unexpected end of JSON input'). The object-list-item
builder emitted an unset String property as a single space " " instead of "".
The chart client feeds customSeriesOptions / customLayout / customConfigurations
to JSON.parse behind an empty-guard (value !== "" ? value : "{}"); a lone
space passes that guard, so the client runs JSON.parse(" ") and throws. mx check
doesn't execute the client, so it stayed green. A Pie (widget-level datasource,
no series object-list) was unaffected — the top-level String path already emitted
"".
Leave an unset String empty, matching Studio Pro and the top-level path, so the
client's empty-guard turns it into "{}". Verified: series customSeriesOptions is
now "" (was " "), zero space-valued primitives; mx check 0 errors and no
CE0463 regression across charts / DataGrid2 / Gallery.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JXnEgoc2NQP1Y2TWMCMXC4
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Three checker hints steered authors the wrong way: - MDL001 (nested loop) recommended `retrieve $Match from $List where … limit 1`, which is a parse error — a plain retrieve cannot filter a list variable. Recommend `$Match = FIND($List, <cond>)` (in-memory, O(N)). Same broken advice fixed in CLAUDE.md idiom #2. - MDL044 flagged `count()` used in an expression with "Did you mean 'round()'?" — count is an aggregate activity, not a typo. For the known aggregates (count/sum/average/minimum/maximum) emit "assign it to a variable first: $n = count($List);" instead of a did-you-mean. - MDL044's generic hint cited `mxcli syntax expressions`, which does not exist; point it at `mxcli syntax microflow`. Also lock in finding #5's second trigger: a microflow-call output variable reused across a fallback chain (try A, else try B) is CE0111. It was already caught by the shared create-output-variable check (`check --references`); add TestValidateDuplicateMicroflowCallOutputVar (same-scope + nested-in-if) as a regression guard and document the correct pattern (one variable per call + a plain set) in write-microflows.md. Reported from the RSS-reader build (findings #7, #8, #14c, #5). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01JXnEgoc2NQP1Y2TWMCMXC4
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…c sugar, ADD doc (FINDINGS #3/#5/#13/#14/#4) Five surprising parser rejects / silent-wrong writes where quoting or a keyword behaved inconsistently with the rest of MDL: - #3 index name can't be quoted: indexDefinition accepted only IDENTIFIER for the name → `index "idx_x" (Col)` was a parse error. Accept QUOTED_IDENTIFIER too (the name is advisory and discarded, as before). - #5 role-name quoting inconsistent: DESCRIBE USER ROLE required quotes, DROP USER ROLE rejected them. Both now accept bare and quoted names; visitors handle both. - #13 `sort by` quoted attribute stored a nonsense reference: a quoted qualified attribute (`sort by "Mod"."Entity"."Code"`) kept the quotes and only failed on write ("attribute does not belong to entity"). buildSortColumnMicroflow now unquotes each segment (bare dotted form), matching the SORT() list-op path. - #14 `DataSource: ASSOCIATION $currentObject/…` didn't parse (keyword + sugar were mutually exclusive). Added the combined grammar branch; the existing VARIABLE&&SLASH visitor branch already handles it correctly. - #4 doc: MDL spec README showed `alter entity … add (Attr: type)`, which the parser rejects. Corrected to `add attribute Attr: type`. Grammar regenerated (`make grammar`). Verified end to end: quoted index name, quoted qualified sort stored as `M.Thing.Code`, describe/drop role in both forms, and `ASSOCIATION $currentObject/…` all parse/store correctly. Tests added. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01JXnEgoc2NQP1Y2TWMCMXC4
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Summary
Fixes a runtime render failure on charts with a
series/lineobject-list (e.g. ColumnChart). Follow-up to #4 (merged); this is the last residual from the widget-authoring testing round.Symptom
A ColumnChart passed
mx check(0 errors) but failed to render with a client-sideJSON.parse('Unexpected end of JSON input')in the chart render path. A Pie chart over the same data (widget-level datasource, no series object-list) rendered fine.Root cause
The object-list-item builder (
createDefaultWidgetValue) emitted an unsetStringproperty as a single space" "instead of"". The chart client feedscustomSeriesOptions/customLayout/customConfigurationsstraight toJSON.parsebehind an empty-guard:A lone space passes that guard (it isn't
""), so the client runsJSON.parse(" ")and throws.mx checknever executes the client, so it stayed green. The Pie path went through the top-level String path, which already emitted""— hence Pie rendered and Column didn't.Fix
Leave an unset
Stringempty (its schema default), matching Studio Pro and the top-level path, so the client's empty-guard turns it into"{}". The" "had no test and no justifying comment (the adjacent TextTemplate case already avoids a single-space value for the same class of reason).Testing
customSeriesOptionsis now""(was" ") — zero space-valued primitives in the generated object.mx check0 errors; no CE0463 regression across the full chart example (all types), DataGrid2, and Gallery.go test ./mdl/backend/... ./mdl/executor/... ./modelsdk/widgets/... ./sdk/widgets/...green.mdl-examples/bug-tests/chart-series-customseriesoptions-json.mdl.🤖 Generated with Claude Code
https://claude.ai/code/session_01JXnEgoc2NQP1Y2TWMCMXC4
Generated by Claude Code