| name | portaljs-add-map |
| description | Render a GeoJSON dataset on an interactive Leaflet map in the Views section of a dataset's showcase. Installs react-leaflet and a Map component, then renders the map for the chosen dataset. Use when a dataset's data is geographic and a map view is needed alongside the showcase's default metadata and download. |
| allowed-tools | Read, Write, Edit, Bash(npm:*), Bash(npx:*), WebFetch |
| 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","map","geojson","leaflet","dataviz"] |
PortalJS — Add Map
Overview
Add an interactive Leaflet map as a view on a dataset's showcase in a
portaljs-catalog portal. The skill installs react-leaflet/leaflet (added directly —
never @portaljs/components), writes a reusable Map component split across
MapView.tsx (the Leaflet code) and Map.tsx (a dynamic(..., { ssr: false }) wrapper,
since Leaflet touches window at module load), and renders <Map /> into the Views
section of the showcase route pages/[owner]/[slug].tsx for one chosen GeoJSON dataset.
The dataset should already carry format: "geojson" in datasets.json; if it doesn't
exist yet, the skill can copy the file and register it first.
Prerequisites
- A scaffolded PortalJS portal (see
portaljs-new-portal).
- The target dataset registered in
datasets.json with format: "geojson" (see
portaljs-add-dataset), or a GeoJSON source file/URL to register.
- Node 18+ and npm available in the portal directory.
Instructions
The canonical, full step-by-step workflow is
.claude/commands/portaljs-add-map.md — the
single source of truth. Read and follow it when executing. Summary:
- Gather input — dataset slug (or a GeoJSON source to register), portal directory. If any
is missing, interview the user; never dead-end on a missing value.
- Validate the portal directory (
datasets.json, package.json,
pages/[owner]/[slug].tsx must exist).
- Resolve the dataset from
datasets.json, or validate and register a new GeoJSON
source (copy to /public/data/, append a manifest entry).
- Install map dependencies:
npm install react-leaflet@^5 leaflet@^1.9 and
npm install -D @types/leaflet (skip if already present).
- Write
components/MapView.tsx and components/Map.tsx (idempotent — skip if
Map.tsx already exists).
- Render
<Map /> 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 it.
- Verify with
npx tsc --noEmit (never next build against a live dev server).
- Report the component, route, and dependency added.
Output
- Created:
components/MapView.tsx and components/Map.tsx (Leaflet wrapper, if
absent); public/data/<slug>.geojson (only when registering a new dataset).
- Modified:
pages/[owner]/[slug].tsx (import + gated <Map /> in Views);
datasets.json (only when registering a new dataset); package.json
(react-leaflet, leaflet, @types/leaflet).
- Verified:
npx tsc --noEmit passes.
- Result: the map renders at
/@<namespace>/<slug> under a "Views" heading.
Error Handling
| Symptom | Cause | Fix |
|---|
| Dataset not found or not GeoJSON | Slug missing from datasets.json or format is tabular | List GeoJSON datasets and re-prompt; suggest portaljs-add-chart for tabular data. |
| Source fetch/copy fails | URL returns non-200 or local path missing | Report the HTTP status or missing path; ask for a corrected source. |
| "Not valid GeoJSON" | Parsed JSON type isn't a Feature/geometry type | Tell the user and point to portaljs-add-dataset for tabular data. |
tsc failure | Bad import path or gating condition | Fix the first reported error before reporting success. |
| Map appears on every dataset | View not gated on (namespace, slug) | Wrap the <Map /> render in the dataset check shown in the Instructions. |
| Features render in the wrong place | Data isn't WGS84 (EPSG:4326) lon/lat | Reproject the source data to WGS84 before adding. |
| Slow render | Thousands of features in one file (>5MB) | Simplify geometries (e.g. mapshaper) before adding. |
Examples
Example 1 — Map an already-registered dataset
/portaljs-add-map dataset=park-boundaries
Example 2 — Register a local GeoJSON file and map it
/portaljs-add-map source=./data/bike-routes.geojson slug=bike-routes name="Bike Routes"
Example 3 — Register a remote GeoJSON URL and map it
/portaljs-add-map source=https://example.com/districts.geojson slug=districts namespace=reference
Resources
