fresh_charts

A charting library for Fresh based on Chart.js, which supports server and client side rendering.

Usage

There are several ways to render a chart.

For server side rendering there is the JSX/TSX component Chart which can be used to inline a chart on a page, and the renderChart() function which can be used to respond in a handler with an SVG image.

For client side rendering there is also a JSX/TSX island component Chart.

[SSR] Inline chart example

This provides a chart rendered within the router page itself.

import { Head } from "$fresh/runtime.ts";
import { Chart } from "$fresh_charts/mod.ts";
import { ChartColors, transparentize } from "$fresh_charts/utils.ts";

export default function Home() {
  return (
    <>
      <Head>
        <title>Example Chart</title>
      </Head>
      <div class="p-4 mx-auto max-w-screen-md">
        <Chart
          type="line"
          options={{
            devicePixelRatio: 1,
            scales: { y: { beginAtZero: true } },
          }}
          data={{
            labels: ["1", "2", "3"],
            datasets: [
              {
                label: "Sessions",
                data: [123, 234, 234],
                borderColor: ChartColors.Red,
                backgroundColor: transparentize(ChartColors.Red, 0.5),
                borderWidth: 1,
              },
              {
                label: "Users",
                data: [346, 233, 123],
                borderColor: ChartColors.Blue,
                backgroundColor: transparentize(ChartColors.Blue, 0.5),
                borderWidth: 1,
              },
            ],
          }}
        />
      </div>
    </>
  );
}

[SSR] Responding as an image

This route will provide the landing page of the site, which has an image link to a route, which will send a request to /routes/chart.ts to render the chart.

/routes/index.tsx

import { Head } from "$fresh/runtime.ts";
import { Chart } from "$fresh_charts/mod.ts";
import { ChartColors, transparentize } from "$fresh_charts/utils.ts";

export default function Home() {
  return (
    <>
      <Head>
        <title>Example Chart</title>
      </Head>
      <div class="p-4 mx-auto max-w-screen-md">
        <img
          src="/chart"
          class="mx-auto my-4 h-96"
          alt="an example chart provided as an image"
        />
      </div>
    </>
  );
}

/routes/chart.ts

import { type Handlers } from "$fresh/server.ts";
import { renderChart } from "$fresh_charts/mod.ts";
import { ChartColors, transparentize } from "$fresh_charts/utils.ts";

export const handler: Handlers = {
  GET() {
    return renderChart({
      type: "line",
      data: {
        labels: ["1", "2", "3"],
        datasets: [
          {
            label: "Sessions",
            data: [123, 234, 234],
            borderColor: ChartColors.Red,
            backgroundColor: transparentize(ChartColors.Red, 0.5),
            borderWidth: 1,
          },
          {
            label: "Users",
            data: [346, 233, 123],
            borderColor: ChartColors.Blue,
            backgroundColor: transparentize(ChartColors.Blue, 0.5),
            borderWidth: 1,
          },
        ],
      },
      options: {
        devicePixelRatio: 1,
        scales: { y: { beginAtZero: true } },
      },
    });
  },
};

[CSR] Inline chart example

This provides a client side rendered and interactive chart island within the router page itself.

/islands/chart.tsx

import { Chart as default } from "$fresh_charts/island.tsx";