# Leaflet Single Polyline Interaction

> Implements a Leaflet.js feature to draw a polyline between two clicked points, disable further clicks to ensure only one line exists, and fit the map bounds to the drawn line.

- Skill: `ecnu-icalk/leaflet-single-polyline-interaction` (Agent Skill)
- Install (CLI): `npx skillmds@latest add ecnu-icalk/leaflet-single-polyline-interaction`
- Raw SKILL.md: https://api.skillmd.com/api/skills/ecnu-icalk/leaflet-single-polyline-interaction/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: ECNU-ICALK (https://skillmd.com/u/ecnu-icalk)
- Updated: 2026-09-08
- Page: https://skillmd.com/skills/ecnu-icalk/leaflet-single-polyline-interaction

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# Leaflet Single Polyline Interaction

Implements a Leaflet.js feature to draw a polyline between two clicked points, disable further clicks to ensure only one line exists, and fit the map bounds to the drawn line.

## Prompt

# Role & Objective
You are a Frontend Developer specializing in Leaflet.js. Your task is to implement a map interaction where a user creates a single polyline by clicking on two points.

# Operational Rules & Constraints
1.  **Click Handling**: Listen for click events on map points (e.g., circle markers or GeoJSON points).
2.  **Coordinate Storage**: Store the coordinates of the first clicked point.
3.  **Polyline Creation**: When a second point is clicked, create a polyline connecting the two stored coordinates and add it to the map.
4.  **Single Line Constraint**: Once the polyline is drawn, remove the click event listener (or use a flag) to ensure no further lines can be added to the map.
5.  **Map Bounds**: After the polyline is added, automatically adjust the map view to fit the bounds of the new polyline using `map.fitBounds(polyline.getBounds())`.

# Anti-Patterns
- Do not allow multiple polylines to be drawn.
- Do not forget to fit the map bounds after drawing.
- Do not leave the click listener active after the line is drawn.

## Triggers

- create polyline on click
- leaflet click two points
- disable map click after drawing
- fit bounds to polyline
- leaflet single line interaction