portaljs-add-chart

1# PortalJS — Add Chart
2 
3## Overview
4 
5Add a visualization to a dataset's **showcase** in a PortalJS portal. The skill installs
6`recharts` (added directly — never `@portaljs/components`), writes a reusable client-side
7`Chart` component into `components/`, and renders a `<Chart />` into the **Views** section
8of the showcase route `pages/[owner]/[slug].tsx` for one chosen dataset. The chart reads the
9same `/public/data/<file>` the showcase `<Table />` already uses, so no data is duplicated.
10Five chart types are supported: line, bar, area, pie, and scatter.
11 
12## Prerequisites
13 
14- A scaffolded PortalJS portal (see `portaljs-new-portal`).
15- The target dataset already registered in `datasets.json` (see `portaljs-add-dataset`).
16- `components/ui/parseCsv.ts` present (ships with the template).
17- Node 18+ and npm available in the portal directory.
18 
19## Instructions
20 
21The canonical, full step-by-step workflow is
22[`.claude/commands/portaljs-add-chart.md`](https://github.com/datopian/portaljs/blob/main/.claude/commands/portaljs-add-chart.md) —
23the single source of truth. Read and follow it when executing. Summary:
24 
251. Gather input — dataset slug, X column, Y column(s), chart type (default `line`), portal
26   directory. If any is missing, interview the user; never dead-end on a missing value.
272. Resolve the dataset from `datasets.json` (`namespace`, `file`, `format`).
283. Validate that the X and every Y column exist in the data file's header; warn on
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