| name | portaljs-add-chart |
| description | Add a chart (line, bar, area, pie, or scatter) to a dataset's showcase in a PortalJS portal. Installs recharts, writes a reusable Chart component, and renders it in the showcase Views section. Use when visualizing a dataset already registered in datasets.json. |
| allowed-tools | Read, Write, Edit, Bash(npm:*), Bash(npx:*) |
| version | 1.0.0 |
| author | Datopian <hello@datopian.com> |
| license | MIT |
| compatibility | Claude Code with PortalJS portals (Next.js 14, React 18, Node 18+). Runs from any project via the plugin, a personal ~/.claude/commands install, or a portaljs clone. |
| tags | ["portaljs","data-portal","chart","recharts","dataviz","nextjs"] |
PortalJS — Add Chart
Overview
Add a visualization to a dataset's showcase in a PortalJS portal. The skill installs
recharts (added directly — never @portaljs/components), writes a reusable client-side
Chart component into components/, and renders a <Chart /> into the Views section
of the showcase route pages/[owner]/[slug].tsx for one chosen dataset. The chart reads the
same /public/data/<file> the showcase <Table /> already uses, so no data is duplicated.
Five chart types are supported: line, bar, area, pie, and scatter.
Prerequisites
- A scaffolded PortalJS portal (see
portaljs-new-portal).
- The target dataset already registered in
datasets.json (see portaljs-add-dataset).
components/ui/parseCsv.ts present (ships with the template).- Node 18+ and npm available in the portal directory.
Instructions
The canonical, full step-by-step workflow is
.claude/commands/portaljs-add-chart.md —
the single source of truth. Read and follow it when executing. Summary:
- Gather input — dataset slug, X column, Y column(s), chart type (default
line), portal
directory. If any is missing, interview the user; never dead-end on a missing value.
- Resolve the dataset from
datasets.json (namespace, file, format).
- Validate that the X and every Y column exist in the data file's header; warn on
non-numeric Y columns (values are coerced with
Number()).
- Install the chart library:
npm install recharts@^2.15.0.
- Write
components/Chart.tsx (idempotent — do not overwrite a customized component).
- Render
<Chart /> into the Views section, gated on the dataset's (namespace, slug) so
other showcases are unaffected. Extend an existing view-dispatch block, do not overwrite.
- Verify with
npx tsc --noEmit.
- Report the component, route, and dependency added.
Output
- Created:
components/Chart.tsx (recharts wrapper, if absent).
- Modified:
pages/[owner]/[slug].tsx (import + gated <Chart /> in Views);
package.json (recharts@^2.15.0).
- Verified:
npx tsc --noEmit passes.
- Result: the chart renders at
/@<namespace>/<slug> under a "Views" heading.
Error Handling
| Symptom | Cause | Fix |
|---|
| Missing dataset/columns | Slug or column not in manifest/header | List available slugs/headers and re-prompt; do not error out. |
| Gaps in the chart | Non-numeric cells coerced to NaN | Clean the source data or pick a numeric Y column. |
tsc failure | Bad column prop or import path | Fix the first reported error before reporting success. |
| Sluggish render | Over ~2,000 SVG points | Pre-aggregate the series (e.g. yearly buckets). |
Examples
Example 1 — Single line series
/portaljs-add-chart co2-emissions x=year y=emissions type=line
Example 2 — Multi-series bar chart
/portaljs-add-chart trade x=year y=imports,exports type=bar
Example 3 — Pie chart of a categorical breakdown
/portaljs-add-chart budget x=department y=amount type=pie
Resources
