---
title: "Polyline Helper - Swift SDK | Mobile sdk | Mobile sdk ios | Ios"
description: "Add polyline features to maps using Swift layer helpers."
---

# Polyline Helper - Swift SDK

This example show how to render LineString/Multiline features with styles options like color, width, dash, and outline.

The vector layer helpers take your data and styling options and create the right source + layers on the current map style with minimal code. Helpers normalize sensible defaults like zoom range, outlines, etc. so you can get results quickly.

![Polyline Helper - Swift SDK](https://docs.maptiler.com/mobile-sdk/ios/assets/img/thumbnails/polyline-helper.png)

## Basic flow

This example show how to render LineString/Multiline features with color, width, dash, and outline.

```swift
import MapTilerSDK

// Assume you have an MTMapView already on screen
let mapView: MTMapView = ...

Task { @MainActor in
    guard let style = mapView.style else { return }

    let helper = MTPolylineLayerHelper(style)

    let lineGeoJSON = """
    {"type":"FeatureCollection","features":[
      {"type":"Feature","geometry":{"type":"LineString","coordinates":[[-122.48,37.80],[-122.40,37.78],[-122.35,37.76]]}},
      {"type":"Feature","geometry":{"type":"LineString","coordinates":[[-122.50,37.74],[-122.43,37.72],[-122.38,37.70]]}}
    ]}
    """

    let options = MTPolylineLayerOptions(
        data: lineGeoJSON,
        lineColor: "#ff7f50",
        lineWidth: 3.0,
        lineOpacity: 0.95,
        lineDashArray: .pattern("__ __ __ __"),
        outline: true,
        outlineColor: "#202020",
        outlineWidth: 1.0,
        outlineOpacity: 0.8
    )

    await helper.addPolyline(options)
}
```

## Learn more

Check the [MTPolylineLayerHelper](https://docs.maptiler.com/mobile-sdk/ios/api/Classes/MTPolylineLayerHelper/) reference to understand how to create and manage point layers.

Review [MTPolylineLayerOptions](https://docs.maptiler.com/mobile-sdk/ios/api/Structs/MTPolylineLayerOptions/) to explore all available configuration options.

## Related examples

### [Point Helper](https://docs.maptiler.com/mobile-sdk/ios/examples/point-helper/)

Examples

Add point features and clustering using Swift layer helpers.

### [Polygon Helper](https://docs.maptiler.com/mobile-sdk/ios/examples/polygon-helper/)

Examples

Add polygon features to maps using Swift layer helpers.

### [Heatmap Helper](https://docs.maptiler.com/mobile-sdk/ios/examples/heatmap-helper/)

Examples

Aggregate point features into heatmaps using Swift SDK helpers.

### [Point Helper Clusters](https://docs.maptiler.com/mobile-sdk/ios/examples/point-helper-cluster/)

Examples

Generate cluster maps using the point layer helper defaults.