Files
school_compare/nextjs-app/components/AdmissionsTrendChart.tsx
T
TudorandClaude Opus 4.8 368b9f2b59 fix(admissions): render trend with Chart.js instead of scaled SVG
The hand-rolled SVG sparkline used px font sizes inside a 520-wide viewBox
that stretched to the full card width, so labels ballooned ~4x and collided —
and with 10+ years of real data the per-point labels and year ticks
overlapped badly, while the oversized chart stretched the "this year" view.

Replace it with a Chart.js line chart (AdmissionsTrendChart) in a fixed
200px wrapper, matching PerformanceChart: responsive px fonts, auto-skipping
x ticks, auto-scaled y-axis clamped to 0-100, emphasised latest point.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-19 18:59:57 +01:00

88 lines
2.6 KiB
TypeScript
Raw Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
'use client';
/**
* AdmissionsTrendChart
* Compact line chart of the first-choice offer rate across admissions years.
* Renders nothing unless at least two years carry an offer-rate value.
*/
import { Line } from 'react-chartjs-2';
import { ChartOptions } from 'chart.js';
import '@/lib/chartSetup';
import { formatAcademicYear } from '@/lib/utils';
import type { SchoolAdmissions } from '@/lib/types';
import styles from './AdmissionsTrendChart.module.css';
export default function AdmissionsTrendChart({ history }: { history: SchoolAdmissions[] }) {
const pts = history.filter((h) => h.first_preference_offer_pct != null);
if (pts.length < 2) return null;
const labels = pts.map((p) => formatAcademicYear(p.year));
const values = pts.map((p) => p.first_preference_offer_pct as number);
const lastIdx = pts.length - 1;
// Auto-scale with headroom so variation is visible, clamped to 0100.
const lo = Math.min(...values);
const hi = Math.max(...values);
const padded = Math.max(5, Math.round((hi - lo) * 0.25));
const yMin = Math.max(0, Math.floor((lo - padded) / 5) * 5);
const yMax = Math.min(100, Math.ceil((hi + padded) / 5) * 5);
const options: ChartOptions<'line'> = {
responsive: true,
maintainAspectRatio: false,
interaction: { mode: 'index', intersect: false },
plugins: {
legend: { display: false },
title: { display: false },
tooltip: {
backgroundColor: 'rgba(26,22,18,0.92)',
padding: 10,
titleFont: { size: 12 },
bodyFont: { size: 12 },
callbacks: {
label: (ctx) => (ctx.parsed.y == null ? '' : `First-choice offers: ${Math.round(ctx.parsed.y)}%`),
},
},
},
scales: {
y: {
min: yMin,
max: yMax,
grid: { color: 'rgba(0,0,0,0.05)' },
ticks: { font: { size: 11 }, maxTicksLimit: 5, callback: (v) => `${v}%` },
},
x: {
grid: { display: false },
ticks: { font: { size: 11 }, autoSkip: true, maxRotation: 0, autoSkipPadding: 16 },
},
},
};
const data = {
labels,
datasets: [
{
label: 'First-choice offer rate',
data: values,
borderColor: '#e07256',
backgroundColor: 'rgba(224,114,86,0.10)',
borderWidth: 2.5,
tension: 0.3,
fill: true,
pointRadius: pts.map((_, i) => (i === lastIdx ? 5 : 3)),
pointBackgroundColor: '#e07256',
pointBorderColor: '#fff',
pointBorderWidth: pts.map((_, i) => (i === lastIdx ? 2 : 0)),
pointHoverRadius: 6,
},
],
};
return (
<div className={styles.wrapper}>
<Line data={data} options={options} />
</div>
);
}