Creating a Line Chart in Svelte using Chart.js

Introduction

• Tutorial on building a line chart in Svelte using Chart.js.
• Chart.js can be tricky with Svelte; covers installation and customization.

Features of the Chart

• Transparent color.
• Thick orange line.
• Enlarging points on hover with tooltips.
• Responsive design.

Chart.js Documentation

• Various chart types: line, bar, etc.
• Configuration details and attributes for customization are available.
• Integration bits for different bundlers, focusing on Rollup in this tutorial.

Getting Started

1. Project Setup
   • Open command prompt in the desired directory.
   • Run npx degit sveltejs/template demo-chart.
   • Navigate to the directory and run npm install.
   • Open the project in VS Code using code ..
2. File Structure
   • Source directory contains main.js and App.svelte.
   • main.js bootstraps the app, loading App.svelte.
3. Running the App
   • Use npm run dev to run the project in a browser.
   • Access the project on localhost:5000.

Integration with Chart.js

1. Installation
   • Visit Chart.js documentation at chartjs.org/docs.
   • Get started with instructions for using bundlers like Rollup.
2. Chart Components
   • Import necessary components and register them.
   • Use a one-liner to import Chart.js and automatically load all chart types.

Building the Chart

1. Canvas Element
   • Create a canvas element in markup with an ID.
   • Bind the canvas element in Svelte to access DOM objects.
2. Script and Function Modifications
   • Use onMount to ensure code runs after DOM rendering.
   • Import Chart.js and configure its components.
   • Adjust the canvas height for responsive design.
3. Modifications for Line Chart
   • Change chart type to line.
   • Set single colors for line and dots.
   • Extract chart data and labels as separate variables.

Customizations

1. Styling the Line Chart
   • Use tension for line curvature.
   • Adjust line borderWidth for thickness.
   • Customize dot sizes and colors.
2. Hover Effects
   • Enlarge dots on hover.
   • Change dot color on hover.
3. Grid and Background Customizations
   • Hide grid lines on specific axes.
   • Add fill color for the chart with transparency.

Conclusion

• Successfully created and customized a line chart in Svelte using Chart.js.
• Encouragement to subscribe for more tutorials.