Files
data-chart-tool/server.js
T
hz4th_coder 2f85dd5b28 feat: 新增7种简约纯色表格风格
新增风格:
- slate 石板灰:专业商务
- sky 天空蓝:清爽明亮
- rose 玫瑰红:优雅大方
- amber 琥珀黄:温暖柔和
- emerald 翡翠绿:高贵典雅
- indigo 靛蓝色:沉稳内敛
- stone 石灰白:极简现代

特点:纯色表头,简洁干净,无渐变效果
2026-07-17 13:14:47 +08:00

996 lines
34 KiB
JavaScript
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const express = require('express');
const cors = require('cors');
const { createCanvas, registerFont } = require('@napi-rs/canvas');
const echarts = require('echarts');
const path = require('path');
// 注册中文字体
try {
registerFont('/usr/share/fonts/opentype/noto/NotoSansCJK-Regular.ttc', { family: 'Noto Sans CJK SC' });
registerFont('/usr/share/fonts/opentype/noto/NotoSansCJK-Bold.ttc', { family: 'Noto Sans CJK SC', weight: 'bold' });
} catch (e) {
console.warn('中文字体注册失败,将使用系统默认字体:', e.message);
}
const app = express();
const PORT = process.env.PORT || 16016;
// 中间件
app.use(cors());
app.use(express.json({ limit: '10mb' }));
app.use(express.urlencoded({ extended: true, limit: '10mb' }));
// 静态文件(前端页面)
app.use(express.static(path.join(__dirname)));
// ===== 预设颜色方案 =====
const colorPalettes = {
default: ['#5470c6', '#91cc75', '#fac858', '#ee6666', '#73c0de', '#3ba272', '#fc8452', '#9a60b4', '#ea7ccc'],
dark: ['#4fc3f7', '#81c784', '#fff176', '#ff8a65', '#ba68c8', '#4dd0e1', '#ffab91', '#aed581', '#f48fb1'],
macarons: ['#2ec7c9', '#b6a2de', '#5ab1ef', '#ffb980', '#d87a80', '#8d98b3', '#e5cf0d', '#97b552', '#95706d'],
gradient: ['#7f7fd5', '#86a8e7', '#91eae4', '#ff6b6b', '#feca57', '#48dbfb', '#ff9ff3', '#54a0ff', '#5f27cd'],
retro: ['#d4a5a5', '#95b9c7', '#f6e8c3', '#dfceb4', '#a4c3b5', '#c9b1ff', '#f5c7b8', '#b8d4e3', '#e8c8a0'],
ocean: ['#0077b6', '#00b4d8', '#90e0ef', '#caf0f8', '#023e8a', '#48cae4', '#ade8f4', '#0096c7', '#03045e'],
forest: ['#2d6a4f', '#40916c', '#52b788', '#74c69d', '#95d5b2', '#b7e4c7', '#d8f3dc', '#1b4332', '#344e41'],
sunset: ['#e85d04', '#f48c06', '#faa307', '#ffba08', '#dc2f02', '#d00000', '#9d0208', '#6a040f', '#370617'],
lavender: ['#7c3aed', '#8b5cf6', '#a78bfa', '#c4b5fd', '#ddd6fe', '#ede9fe', '#5b21b6', '#4c1d95', '#6d28d9'],
minimal: ['#111827', '#374151', '#6b7280', '#9ca3af', '#d1d5db', '#e5e7eb', '#f3f4f6', '#4b5563', '#1f2937'],
cherry: ['#e91e63', '#f06292', '#f48fb1', '#f8bbd0', '#fce4ec', '#c2185b', '#ad1457', '#880e4f', '#d81b60'],
midnight: ['#6c63ff', '#5a52d5', '#483fb5', '#7c79ff', '#3d3d5c', '#8b89ff', '#9d9bff', '#2c2c4a', '#b3b2ff'],
gold: ['#b8860b', '#daa520', '#f0c040', '#ffd700', '#ffe066', '#996515', '#cc9900', '#e6b800', '#8b6914'],
coral: ['#ff6f61', '#ff8a70', '#ffa07a', '#ffab91', '#ffccbc', '#e64a19', '#f4511e', '#ff5722', '#d84315'],
mint: ['#00bfa5', '#26a69a', '#4db6ac', '#80cbc4', '#b2dfdb', '#00897b', '#00796b', '#004d40', '#009688']
};
// ===== 数据解析(与前端一致) =====
function parseData(rawText) {
const lines = rawText.trim().split('\n').filter(l => l.trim());
if (lines.length < 2) {
throw new Error('数据至少需要包含表头和一行数据');
}
// 自动检测分隔符
let delimiter = ',';
if (lines[0].includes('\t')) {
delimiter = '\t';
} else if (lines[0].split('|').length > lines[0].split(',').length) {
delimiter = '|';
}
const rows = lines.map(line => {
return line.split(delimiter).map(cell => cell.trim());
});
const headers = rows[0];
const categories = [];
const seriesData = {};
for (let i = 1; i < headers.length; i++) {
seriesData[headers[i]] = [];
}
for (let i = 1; i < rows.length; i++) {
categories.push(rows[i][0]);
for (let j = 1; j < rows[i].length && j < headers.length; j++) {
const val = parseFloat(rows[i][j]);
seriesData[headers[j]].push(isNaN(val) ? 0 : val);
}
}
return {
categories,
seriesNames: headers.slice(1),
seriesData
};
}
// ===== 颜色工具 =====
function adjustColor(hex, amount) {
hex = hex.replace('#', '');
const num = parseInt(hex, 16);
let r = Math.min(255, ((num >> 16) & 0xff) + amount);
let g = Math.min(255, ((num >> 8) & 0xff) + amount);
let b = Math.min(255, (num & 0xff) + amount);
return `rgb(${r},${g},${b})`;
}
// ===== 构建 ECharts option =====
function buildChartOption(params) {
const {
data,
chartType = 'bar',
title = '',
theme = 'default',
showLegend = true,
showGrid = true,
showLabel = false,
stackMode = false,
smoothLine = true,
enableSplit = false,
splitIndex = 3,
leftLabel = '左侧',
rightLabel = '右侧',
splitStyle = 'solid',
seriesColors: customColors = null
} = params;
const parsedData = parseData(data);
const palette = colorPalettes[theme] || colorPalettes.default;
const seriesColorsArr = customColors || parsedData.seriesNames.map((_, i) => palette[i % palette.length]);
// 背景色和文字色
const bgColor = theme === 'dark' ? '#1a1a2e' : '#ffffff';
const textColor = theme === 'dark' ? '#e0e0e0' : '#333333';
const axisLineColor = theme === 'dark' ? '#444' : '#ddd';
// 构建系列
const series = parsedData.seriesNames.map((name, idx) => {
const dataArr = parsedData.seriesData[name];
const color = seriesColorsArr[idx] || palette[idx % palette.length];
let type = chartType === 'bar-line'
? (idx % 2 === 0 ? 'bar' : 'line')
: chartType;
const seriesItem = {
name: name,
type: type,
data: [...dataArr],
itemStyle: { color: color },
emphasis: {
focus: 'series',
itemStyle: {
shadowBlur: 10,
shadowColor: 'rgba(0,0,0,0.3)'
}
}
};
if (stackMode) {
seriesItem.stack = 'total';
}
if (type === 'line') {
seriesItem.smooth = smoothLine;
seriesItem.lineStyle = { width: 3 };
seriesItem.symbolSize = 8;
seriesItem.areaStyle = theme === 'gradient' ? { opacity: 0.15 } : undefined;
}
if (type === 'bar') {
seriesItem.barMaxWidth = 40;
seriesItem.itemStyle.borderRadius = stackMode ? [0, 0, 0, 0] : [4, 4, 0, 0];
}
if (showLabel) {
seriesItem.label = {
show: true,
position: 'top',
fontSize: 11,
color: textColor,
formatter: (p) => {
if (p.value >= 10000) return (p.value / 10000).toFixed(1) + 'w';
if (p.value >= 1000) return (p.value / 1000).toFixed(1) + 'k';
return p.value;
}
};
}
return seriesItem;
});
// 区域分割
if (enableSplit && splitIndex < parsedData.categories.length && series.length > 0) {
const splitLineColor = theme === 'dark' ? '#ff6b6b' : '#e74c3c';
series[0].markArea = {
silent: true,
data: [
[
{
name: leftLabel,
xAxis: parsedData.categories[0],
itemStyle: {
color: theme === 'dark' ? 'rgba(79,195,247,0.06)' : 'rgba(79,70,229,0.05)',
borderWidth: 0
},
label: {
show: true,
position: 'insideTop',
fontSize: 13,
fontWeight: 'bold',
color: theme === 'dark' ? '#4fc3f7' : '#4f46e5',
offset: [0, 10]
}
},
{ xAxis: parsedData.categories[splitIndex - 1] }
],
[
{
name: rightLabel,
xAxis: parsedData.categories[splitIndex],
itemStyle: {
color: theme === 'dark' ? 'rgba(255,107,107,0.06)' : 'rgba(239,68,68,0.05)',
borderWidth: 0
},
label: {
show: true,
position: 'insideTop',
fontSize: 13,
fontWeight: 'bold',
color: theme === 'dark' ? '#ff6b6b' : '#ef4444',
offset: [0, 10]
}
},
{ xAxis: parsedData.categories[parsedData.categories.length - 1] }
]
]
};
}
// 完整 option
const option = {
backgroundColor: bgColor,
title: title ? {
text: title,
left: 'center',
top: 15,
textStyle: {
color: textColor,
fontSize: 18,
fontWeight: 600
}
} : undefined,
tooltip: { show: false },
legend: showLegend ? {
show: true,
top: title ? 50 : 15,
textStyle: { color: textColor, fontSize: 12 },
itemGap: 20,
icon: 'roundRect'
} : { show: false },
grid: {
left: '3%',
right: '4%',
bottom: '3%',
top: showLegend ? (title ? 90 : 60) : (title ? 60 : 30),
containLabel: true
},
xAxis: {
type: 'category',
data: parsedData.categories,
axisLine: { lineStyle: { color: axisLineColor } },
axisLabel: {
color: textColor,
fontSize: 12,
interval: 0,
rotate: parsedData.categories.length > 10 ? 30 : 0
},
axisTick: { show: false }
},
yAxis: {
type: 'value',
axisLine: { show: false },
axisTick: { show: false },
axisLabel: { color: textColor, fontSize: 11 },
splitLine: {
show: showGrid,
lineStyle: {
color: theme === 'dark' ? '#333' : '#f0f0f0',
type: 'dashed'
}
}
},
series: series,
animation: false // 服务端渲染关闭动画
};
return option;
}
// ===== API: 生成图表图片 =====
app.post('/api/chart', (req, res) => {
try {
const params = req.body;
if (!params.data) {
return res.status(400).json({ error: '缺少 data 参数(CSV 格式数据)' });
}
const width = parseInt(params.width) || 800;
const height = parseInt(params.height) || 500;
const format = params.format || 'png';
const pixelRatio = parseInt(params.pixelRatio) || 2;
// 构建图表配置
const option = buildChartOption(params);
// 创建 canvas 并渲染
const canvas = createCanvas(width * pixelRatio, height * pixelRatio);
const chart = echarts.init(canvas, null, {
renderer: 'canvas',
width: width,
height: height,
devicePixelRatio: pixelRatio
});
chart.setOption(option);
// 输出图片
if (format === 'svg') {
// SVG 需要用 SVG 渲染器重新渲染
// node-canvas 不支持 SVG,返回 PNG 并提示
const buffer = canvas.toBuffer('image/png');
res.set({
'Content-Type': 'image/png',
'Content-Length': buffer.length,
'X-Chart-Format': 'png',
'X-Chart-Note': 'SVG format not supported in server-side rendering, returned PNG instead'
});
res.send(buffer);
} else {
const buffer = canvas.toBuffer('image/png');
res.set({
'Content-Type': 'image/png',
'Content-Length': buffer.length,
'X-Chart-Width': width,
'X-Chart-Height': height,
'X-Chart-Pixel-Ratio': pixelRatio
});
res.send(buffer);
}
chart.dispose();
} catch (err) {
console.error('Chart generation error:', err);
res.status(500).json({ error: '图表生成失败: ' + err.message });
}
});
// ===== API: 生成图表(GET 方式,方便 URL 直接调用) =====
app.get('/api/chart', (req, res) => {
try {
const params = {
data: req.query.data,
chartType: req.query.chartType || req.query.type || 'bar',
title: req.query.title || '',
theme: req.query.theme || 'default',
showLegend: req.query.showLegend !== 'false',
showGrid: req.query.showGrid !== 'false',
showLabel: req.query.showLabel === 'true',
stackMode: req.query.stackMode === 'true',
smoothLine: req.query.smoothLine !== 'false',
enableSplit: req.query.enableSplit === 'true',
splitIndex: parseInt(req.query.splitIndex) || 3,
leftLabel: req.query.leftLabel || '左侧',
rightLabel: req.query.rightLabel || '右侧',
splitStyle: req.query.splitStyle || 'solid',
width: parseInt(req.query.width) || 800,
height: parseInt(req.query.height) || 500,
format: req.query.format || 'png',
pixelRatio: parseInt(req.query.pixelRatio) || 2
};
if (!params.data) {
return res.status(400).json({ error: '缺少 data 参数' });
}
// 解码 data(支持 URL 编码的换行符)
params.data = params.data.replace(/\\n/g, '\n');
const option = buildChartOption(params);
const width = params.width;
const height = params.height;
const pixelRatio = params.pixelRatio;
const canvas = createCanvas(width * pixelRatio, height * pixelRatio);
const chart = echarts.init(canvas, null, {
renderer: 'canvas',
width: width,
height: height,
devicePixelRatio: pixelRatio
});
chart.setOption(option);
const buffer = canvas.toBuffer('image/png');
res.set({
'Content-Type': 'image/png',
'Content-Length': buffer.length,
'X-Chart-Width': width,
'X-Chart-Height': height
});
res.send(buffer);
chart.dispose();
} catch (err) {
console.error('Chart generation error:', err);
res.status(500).json({ error: '图表生成失败: ' + err.message });
}
});
// ===== 表格数据解析(保留原始文本) =====
function parseTableData(rawText) {
const lines = rawText.trim().split('\n').filter(l => l.trim());
if (lines.length < 2) {
throw new Error('数据至少需要包含表头和一行数据');
}
// 自动检测分隔符
let delimiter = ',';
if (lines[0].includes('\t')) {
delimiter = '\t';
} else if (lines[0].split('|').length > lines[0].split(',').length) {
delimiter = '|';
}
const rows = lines.map(line => {
return line.split(delimiter).map(cell => cell.trim());
});
return {
headers: rows[0],
rows: rows.slice(1)
};
}
// ===== 表格主题配置 =====
const tableThemes = {
default: {
bgColor: '#ffffff',
headerBg: '#5470c6',
headerColor: '#ffffff',
cellColor: '#333333',
borderColor: '#e0e0e0',
stripeColor: '#f8f9fa',
titleColor: '#333333'
},
dark: {
bgColor: '#1a1a2e',
headerBg: '#4fc3f7',
headerColor: '#1a1a2e',
cellColor: '#e0e0e0',
borderColor: '#444444',
stripeColor: '#252540',
titleColor: '#e0e0e0'
},
macarons: {
bgColor: '#ffffff',
headerBg: '#2ec7c9',
headerColor: '#ffffff',
cellColor: '#333333',
borderColor: '#e8e8e8',
stripeColor: '#f0fafb',
titleColor: '#333333'
},
gradient: {
bgColor: '#ffffff',
headerBg: '#7f7fd5',
headerColor: '#ffffff',
cellColor: '#333333',
borderColor: '#e8e8e8',
stripeColor: '#f5f5ff',
titleColor: '#333333'
},
retro: {
bgColor: '#fefefe',
headerBg: '#95b9c7',
headerColor: '#ffffff',
cellColor: '#444444',
borderColor: '#d4a5a5',
stripeColor: '#f6e8c3',
titleColor: '#444444'
},
ocean: {
bgColor: '#f0f8ff',
headerBg: '#0077b6',
headerColor: '#ffffff',
cellColor: '#023e58',
borderColor: '#90e0ef',
stripeColor: '#caf0f8',
titleColor: '#023e58'
},
forest: {
bgColor: '#f5faf5',
headerBg: '#2d6a4f',
headerColor: '#ffffff',
cellColor: '#1b4332',
borderColor: '#95d5b2',
stripeColor: '#d8f3dc',
titleColor: '#1b4332'
},
sunset: {
bgColor: '#fff8f0',
headerBg: '#e85d04',
headerColor: '#ffffff',
cellColor: '#6a040f',
borderColor: '#ffba08',
stripeColor: '#fff3e0',
titleColor: '#6a040f'
},
lavender: {
bgColor: '#faf5ff',
headerBg: '#7c3aed',
headerColor: '#ffffff',
cellColor: '#4c1d95',
borderColor: '#c4b5fd',
stripeColor: '#ede9fe',
titleColor: '#4c1d95'
},
minimal: {
bgColor: '#ffffff',
headerBg: '#f8f9fa',
headerColor: '#212529',
cellColor: '#495057',
borderColor: '#dee2e6',
stripeColor: '#f8f9fa',
titleColor: '#212529'
},
cherry: {
bgColor: '#fff5f7',
headerBg: '#e91e63',
headerColor: '#ffffff',
cellColor: '#880e4f',
borderColor: '#f48fb1',
stripeColor: '#fce4ec',
titleColor: '#880e4f'
},
midnight: {
bgColor: '#1a1a2e',
headerBg: '#6c63ff',
headerColor: '#ffffff',
cellColor: '#e0e0e0',
borderColor: '#3d3d5c',
stripeColor: '#22223a',
titleColor: '#e0e0e0'
},
gold: {
bgColor: '#fffef5',
headerBg: '#b8860b',
headerColor: '#ffffff',
cellColor: '#5c4a00',
borderColor: '#daa520',
stripeColor: '#fdf6e3',
titleColor: '#5c4a00'
},
coral: {
bgColor: '#fff5f2',
headerBg: '#ff6f61',
headerColor: '#ffffff',
cellColor: '#5d2b1f',
borderColor: '#ffab91',
stripeColor: '#fff0ed',
titleColor: '#5d2b1f'
},
mint: {
bgColor: '#f0fff8',
headerBg: '#00bfa5',
headerColor: '#ffffff',
cellColor: '#004d40',
borderColor: '#80cbc4',
stripeColor: '#e0f2f1',
titleColor: '#004d40'
},
// 简约纯色风格
slate: {
bgColor: '#ffffff',
headerBg: '#475569',
headerColor: '#ffffff',
cellColor: '#334155',
borderColor: '#cbd5e1',
stripeColor: '#f8fafc',
titleColor: '#1e293b'
},
sky: {
bgColor: '#ffffff',
headerBg: '#0ea5e9',
headerColor: '#ffffff',
cellColor: '#0c4a6e',
borderColor: '#bae6fd',
stripeColor: '#f0f9ff',
titleColor: '#0c4a6e'
},
rose: {
bgColor: '#ffffff',
headerBg: '#e11d48',
headerColor: '#ffffff',
cellColor: '#881337',
borderColor: '#fecdd3',
stripeColor: '#fff1f2',
titleColor: '#881337'
},
amber: {
bgColor: '#ffffff',
headerBg: '#f59e0b',
headerColor: '#ffffff',
cellColor: '#78350f',
borderColor: '#fde68a',
stripeColor: '#fffbeb',
titleColor: '#78350f'
},
emerald: {
bgColor: '#ffffff',
headerBg: '#10b981',
headerColor: '#ffffff',
cellColor: '#064e3b',
borderColor: '#a7f3d0',
stripeColor: '#ecfdf5',
titleColor: '#064e3b'
},
indigo: {
bgColor: '#ffffff',
headerBg: '#6366f1',
headerColor: '#ffffff',
cellColor: '#312e81',
borderColor: '#c7d2fe',
stripeColor: '#eef2ff',
titleColor: '#312e81'
},
stone: {
bgColor: '#ffffff',
headerBg: '#78716c',
headerColor: '#ffffff',
cellColor: '#44403c',
borderColor: '#d6d3d1',
stripeColor: '#fafaf9',
titleColor: '#292524'
}
};
// ===== 测量文字宽度 =====
function measureTextWidth(ctx, text, fontSize) {
ctx.font = `${fontSize}px "Noto Sans CJK SC", sans-serif`;
const metrics = ctx.measureText(text);
return metrics.width;
}
// ===== 生成表格图片 =====
function generateTableImage(params) {
const {
data,
title = '',
theme = 'default',
fontSize = 14,
cellPadding = 12,
borderWidth = 1,
stripeRows = true,
pixelRatio = 2,
maxWidth = 1200
} = params;
const tableData = parseTableData(data);
const { headers, rows } = tableData;
const themeConfig = tableThemes[theme] || tableThemes.default;
// 创建临时 canvas 用于测量文字
const tempCanvas = createCanvas(100, 100);
const tempCtx = tempCanvas.getContext('2d');
// 计算每列最大宽度
const colWidths = headers.map((header, colIdx) => {
let maxW = measureTextWidth(tempCtx, header, fontSize) + cellPadding * 2;
rows.forEach(row => {
if (row[colIdx]) {
const cellW = measureTextWidth(tempCtx, row[colIdx], fontSize) + cellPadding * 2;
if (cellW > maxW) maxW = cellW;
}
});
return Math.min(maxW, 300); // 单列最大宽度 300px
});
// 计算表格总宽度
const tableWidth = colWidths.reduce((sum, w) => sum + w, 0) + borderWidth * 2;
const finalWidth = Math.min(tableWidth, maxWidth);
// 如果超出最大宽度,按比例缩放列宽
if (tableWidth > maxWidth) {
const scale = maxWidth / tableWidth;
colWidths.forEach((_, i) => colWidths[i] *= scale);
}
// 计算行高
const headerHeight = fontSize * 2.5;
const rowHeight = fontSize * 2.2;
const titleHeight = title ? fontSize * 3 : 0;
const tableHeight = headerHeight + rows.length * rowHeight + borderWidth * 2;
const finalHeight = tableHeight + titleHeight;
// 创建正式 canvas
const canvas = createCanvas(finalWidth * pixelRatio, finalHeight * pixelRatio);
const ctx = canvas.getContext('2d');
ctx.scale(pixelRatio, pixelRatio);
// 绘制背景
ctx.fillStyle = themeConfig.bgColor;
ctx.fillRect(0, 0, finalWidth, finalHeight);
let startY = 0;
// 绘制标题
if (title) {
ctx.fillStyle = themeConfig.titleColor;
ctx.font = `bold ${fontSize * 1.4}px "Noto Sans CJK SC", sans-serif`;
ctx.textAlign = 'center';
ctx.textBaseline = 'middle';
ctx.fillText(title, finalWidth / 2, titleHeight / 2);
startY = titleHeight;
}
// 绘制表头背景
ctx.fillStyle = themeConfig.headerBg;
ctx.fillRect(0, startY, finalWidth, headerHeight);
// 绘制表头文字
ctx.fillStyle = themeConfig.headerColor;
ctx.font = `bold ${fontSize}px "Noto Sans CJK SC", sans-serif`;
ctx.textAlign = 'left';
ctx.textBaseline = 'middle';
let x = 0;
headers.forEach((header, i) => {
ctx.fillText(header, x + cellPadding, startY + headerHeight / 2, colWidths[i] - cellPadding * 2);
x += colWidths[i];
});
// 绘制数据行
rows.forEach((row, rowIdx) => {
const y = startY + headerHeight + rowIdx * rowHeight;
// 斑马纹背景
if (stripeRows && rowIdx % 2 === 1) {
ctx.fillStyle = themeConfig.stripeColor;
ctx.fillRect(0, y, finalWidth, rowHeight);
}
// 绘制单元格文字
ctx.fillStyle = themeConfig.cellColor;
ctx.font = `${fontSize}px "Noto Sans CJK SC", sans-serif`;
ctx.textAlign = 'left';
ctx.textBaseline = 'middle';
let cellX = 0;
row.forEach((cell, colIdx) => {
if (cell && colWidths[colIdx]) {
ctx.fillText(cell, cellX + cellPadding, y + rowHeight / 2, colWidths[colIdx] - cellPadding * 2);
}
cellX += colWidths[colIdx];
});
});
// 绘制边框
ctx.strokeStyle = themeConfig.borderColor;
ctx.lineWidth = borderWidth;
// 外边框
ctx.strokeRect(0, startY, finalWidth, tableHeight);
// 横线
ctx.beginPath();
ctx.moveTo(0, startY + headerHeight);
ctx.lineTo(finalWidth, startY + headerHeight);
ctx.stroke();
rows.forEach((_, rowIdx) => {
const y = startY + headerHeight + (rowIdx + 1) * rowHeight;
ctx.beginPath();
ctx.moveTo(0, y);
ctx.lineTo(finalWidth, y);
ctx.stroke();
});
// 竖线
x = 0;
colWidths.forEach((width, i) => {
if (i > 0) {
ctx.beginPath();
ctx.moveTo(x, startY);
ctx.lineTo(x, startY + tableHeight);
ctx.stroke();
}
x += width;
});
return canvas;
}
// ===== API: 生成表格图片 (POST) =====
app.post('/api/table', (req, res) => {
try {
const params = req.body;
if (!params.data) {
return res.status(400).json({ error: '缺少 data 参数(CSV 格式数据)' });
}
const pixelRatio = parseInt(params.pixelRatio) || 2;
const canvas = generateTableImage(params);
const buffer = canvas.toBuffer('image/png');
res.set({
'Content-Type': 'image/png',
'Content-Length': buffer.length,
'X-Table-Format': 'png'
});
res.send(buffer);
} catch (err) {
console.error('Table generation error:', err);
res.status(500).json({ error: '表格生成失败: ' + err.message });
}
});
// ===== API: 生成表格图片 (GET) =====
app.get('/api/table', (req, res) => {
try {
const params = {
data: req.query.data,
title: req.query.title || '',
theme: req.query.theme || 'default',
fontSize: parseInt(req.query.fontSize) || 14,
cellPadding: parseInt(req.query.cellPadding) || 12,
borderWidth: parseInt(req.query.borderWidth) || 1,
stripeRows: req.query.stripeRows !== 'false',
pixelRatio: parseInt(req.query.pixelRatio) || 2,
maxWidth: parseInt(req.query.maxWidth) || 1200
};
if (!params.data) {
return res.status(400).json({ error: '缺少 data 参数' });
}
// 解码 data(支持 URL 编码的换行符)
params.data = params.data.replace(/\\n/g, '\n');
const canvas = generateTableImage(params);
const buffer = canvas.toBuffer('image/png');
res.set({
'Content-Type': 'image/png',
'Content-Length': buffer.length,
'X-Table-Format': 'png'
});
res.send(buffer);
} catch (err) {
console.error('Table generation error:', err);
res.status(500).json({ error: '表格生成失败: ' + err.message });
}
});
// ===== API: 健康检查 =====
app.get('/api/health', (req, res) => {
res.json({
status: 'ok',
service: 'data-chart-tool',
version: '1.2.0',
endpoints: {
'POST /api/chart': '生成图表图片(JSON body',
'GET /api/chart': '生成图表图片(URL 参数)',
'POST /api/table': '生成表格图片(JSON body',
'GET /api/table': '生成表格图片(URL 参数)',
'GET /api/health': '健康检查'
}
});
});
// ===== API: 文档/使用说明 =====
app.get('/api/docs', (req, res) => {
res.json({
name: '数据可视化图表生成器 API',
version: '1.2.0',
endpoints: [
{
method: 'POST',
path: '/api/chart',
description: '通过 JSON 请求体生成图表图片',
'Content-Type': 'application/json',
params: {
data: { type: 'string', required: true, description: 'CSV 格式数据(第一行表头,第一列横坐标)' },
chartType: { type: 'string', default: 'bar', options: ['bar', 'line', 'bar-line'], description: '图表类型' },
title: { type: 'string', default: '', description: '图表标题' },
theme: { type: 'string', default: 'default', options: ['default', 'dark', 'macarons', 'gradient', 'retro', 'ocean', 'forest', 'sunset', 'lavender', 'minimal', 'cherry', 'midnight', 'gold', 'coral', 'mint'], description: '主题风格' },
showLegend: { type: 'boolean', default: true, description: '是否显示图例' },
showGrid: { type: 'boolean', default: true, description: '是否显示网格线' },
showLabel: { type: 'boolean', default: false, description: '是否显示数据标签' },
stackMode: { type: 'boolean', default: false, description: '是否堆叠模式' },
smoothLine: { type: 'boolean', default: true, description: '折线图是否平滑' },
enableSplit: { type: 'boolean', default: false, description: '是否启用区域分割' },
splitIndex: { type: 'number', default: 3, description: '分割位置索引' },
leftLabel: { type: 'string', default: '左侧', description: '左侧区域标签' },
rightLabel: { type: 'string', default: '右侧', description: '右侧区域标签' },
splitStyle: { type: 'string', default: 'solid', options: ['solid', 'dashed', 'dotted'], description: '分割线样式' },
width: { type: 'number', default: 800, description: '图片宽度(px)' },
height: { type: 'number', default: 500, description: '图片高度(px)' },
format: { type: 'string', default: 'png', options: ['png'], description: '输出格式' },
pixelRatio: { type: 'number', default: 2, description: '像素倍率(清晰度)' }
},
returns: 'image/png',
example: {
request: `curl -X POST http://localhost:16016/api/chart \\
-H "Content-Type: application/json" \\
-d '{
"data": "产品, Q1, Q2, Q3, Q4\\n手机, 1200, 1800, 2100, 2500\\n平板, 800, 950, 1100, 1300",
"chartType": "bar",
"title": "季度销售对比",
"theme": "default",
"width": 800,
"height": 500
}' -o chart.png`,
response: 'PNG 图片二进制流'
}
},
{
method: 'GET',
path: '/api/chart',
description: '通过 URL 参数生成图表图片(适合简单场景)',
params: {
data: { type: 'string', required: true, description: 'CSV 数据(换行用 \\n 分隔)' },
type: { type: 'string', default: 'bar', description: '图表类型' },
title: { type: 'string', description: '图表标题' },
theme: { type: 'string', default: 'default', description: '主题风格' },
width: { type: 'number', default: 800 },
height: { type: 'number', default: 500 }
},
returns: 'image/png',
example: {
request: `curl "http://localhost:16016/api/chart?data=产品,Q1,Q2\\n手机,100,200\\n平板,150,250&type=bar&title=测试" -o chart.png`
}
},
{
method: 'POST',
path: '/api/table',
description: '通过 JSON 请求体生成表格图片',
'Content-Type': 'application/json',
params: {
data: { type: 'string', required: true, description: 'CSV 格式数据(第一行表头)' },
title: { type: 'string', default: '', description: '表格标题' },
theme: { type: 'string', default: 'default', options: ['default', 'dark', 'macarons', 'gradient', 'retro', 'ocean', 'forest', 'sunset', 'lavender', 'minimal', 'cherry', 'midnight', 'gold', 'coral', 'mint'], description: '主题风格' },
fontSize: { type: 'number', default: 14, description: '字体大小' },
cellPadding: { type: 'number', default: 12, description: '单元格内边距' },
borderWidth: { type: 'number', default: 1, description: '边框宽度' },
stripeRows: { type: 'boolean', default: true, description: '是否斑马纹' },
pixelRatio: { type: 'number', default: 2, description: '像素倍率(清晰度)' },
maxWidth: { type: 'number', default: 1200, description: '最大宽度(px)' }
},
returns: 'image/png',
example: {
request: `curl -X POST http://localhost:16016/api/table \\
-H "Content-Type: application/json" \\
-d '{
"data": "姓名, 部门, 职位, 薪资\\n张三, 技术部, 工程师, 15000\\n李四, 产品部, 产品经理, 18000\\n王五, 设计部, UI设计师, 16000",
"title": "员工信息表",
"theme": "default"
}' -o table.png`,
response: 'PNG 图片二进制流'
}
},
{
method: 'GET',
path: '/api/table',
description: '通过 URL 参数生成表格图片',
params: {
data: { type: 'string', required: true, description: 'CSV 数据(换行用 \\n 分隔)' },
title: { type: 'string', description: '表格标题' },
theme: { type: 'string', default: 'default', description: '主题风格' },
fontSize: { type: 'number', default: 14 },
stripeRows: { type: 'boolean', default: true }
},
returns: 'image/png',
example: {
request: `curl "http://localhost:16016/api/table?data=产品,价格,库存\\n手机,2999,100\\n平板,1999,50&title=产品列表" -o table.png`
}
}
]
});
});
// ===== 启动服务 =====
app.listen(PORT, '0.0.0.0', () => {
console.log(`🚀 数据可视化图表生成器已启动`);
console.log(`📊 Web UI: http://0.0.0.0:${PORT}`);
console.log(`📡 图表API: http://0.0.0.0:${PORT}/api/chart`);
console.log(`📋 表格API: http://0.0.0.0:${PORT}/api/table`);
console.log(`📖 文档: http://0.0.0.0:${PORT}/api/docs`);
console.log(`❤️ 健康: http://0.0.0.0:${PORT}/api/health`);
});