name: delon-chart
description: '@delon/chart skill - G2Plot enterprise charting components with @delon/chart. For ng-events construction site progress tracking system.'

@delon/chart - Enterprise Chart Components

Trigger patterns: "chart", "graph", "visualization", "@delon/chart", "G2Plot", "G2"

Overview

@delon/chart provides enterprise-grade charting components built on G2Plot for data visualization in ng-alain applications.

Package: @delon/chart@20.1.0
Dependencies: @ant-design/charts (G2Plot wrapper)

Core Components

1. chart-card - Chart Card Container

import { ChartCardComponent } from '@delon/chart/chart-card';

<chart-card 
  [title]="'進度統計'" 
  [total]="totalTasks()"
  [action]="action"
  [footer]="footer"
>
  <trend flag="up" style="margin-right: 16px;">
    <span>週成長</span><span>12%</span>
  </trend>
  <trend flag="down">
    <span>日成長</span><span>11%</span>
  </trend>
</chart-card>

Features:

• Title, total, action, footer slots
• Integrated trend indicators
• Responsive layout
• Loading states

2. g2-bar - Bar Charts

import { G2BarComponent } from '@delon/chart/bar';

@Component({
  standalone: true,
  imports: [G2BarComponent],
  template: `
    <g2-bar 
      [data]="barData()"
      [height]="300"
      [padding]="[20, 40, 50, 40]"
    />
  `
})
export class TaskChartComponent {
  barData = signal([
    { x: '待辦', y: 12 },
    { x: '進行中', y: 8 },
    { x: '已完成', y: 25 }
  ]);
}

Options:

• height (number) - Chart height in pixels
• padding (number[]) - [top, right, bottom, left]
• color (string) - Bar color
• autoLabel (boolean) - Auto label positioning

3. g2-mini-bar - Mini Bar Charts (Sparkline)

<g2-mini-bar 
  [data]="miniData()"
  [height]="50"
  [color]="'#1890ff'"
/>

miniData = signal([
  { x: '2024-01', y: 5 },
  { x: '2024-02', y: 8 },
  { x: '2024-03', y: 12 }
]);

4. g2-pie - Pie/Donut Charts

import { G2PieComponent } from '@delon/chart/pie';

<g2-pie
  [data]="pieData()"
  [height]="300"
  [hasLegend]="true"
  [subTitle]="'總任務數'"
  [total]="totalTasks()"
  [inner]="0.8"
/>

pieData = signal([
  { x: '待辦', y: 12 },
  { x: '進行中', y: 8 },
  { x: '已完成', y: 25 }
]);

Options:

• inner (number) - 0-1, 0=pie, >0=donut
• hasLegend (boolean) - Show legend
• subTitle (string) - Center subtitle
• total (string) - Center total display

5. g2-radar - Radar Charts

import { G2RadarComponent } from '@delon/chart/radar';

<g2-radar 
  [data]="radarData()"
  [height]="300"
  [hasLegend]="true"
/>

radarData = signal([
  { name: '設計', label: '計畫', value: 85 },
  { name: '設計', label: '執行', value: 70 },
  { name: '開發', label: '計畫', value: 90 },
  { name: '開發', label: '執行', value: 80 }
]);

6. timeline - Timeline Charts

import { TimelineComponent } from '@delon/chart/timeline';

<timeline 
  [data]="timelineData()"
  [title]="'施工進度'"
  [maxAxis]="5"
/>

timelineData = signal([
  { x: new Date('2024-01-01'), y1: 10, y2: 20 },
  { x: new Date('2024-02-01'), y1: 15, y2: 25 },
  { x: new Date('2024-03-01'), y1: 20, y2: 30 }
]);

7. trend - Trend Indicator

import { TrendComponent } from '@delon/chart/trend';

<trend flag="up">
  <span>週成長</span>
  <span class="pl-sm">12%</span>
</trend>

<trend flag="down" colorful="false">
  <span>日成長</span>
  <span class="pl-sm">11%</span>
</trend>

Flags: up | down
Colorful: true (green/red) | false (gray)

Real-World Examples

Dashboard Stats with Charts

import { Component, signal, computed, inject } from '@angular/core';
import { ChartCardComponent } from '@delon/chart/chart-card';
import { G2BarComponent } from '@delon/chart/bar';
import { G2PieComponent } from '@delon/chart/pie';
import { TrendComponent } from '@delon/chart/trend';
import { TaskService } from '@core/services/task.service';

@Component({
  selector: 'app-dashboard',
  standalone: true,
  imports: [
    ChartCardComponent,
    G2BarComponent,
    G2PieComponent,
    TrendComponent
  ],
  template: `
    <div nz-row [nzGutter]="24">
      <div nz-col [nzXl]="6" [nzLg]="12" [nzMd]="12" [nzSm]="24">
        <chart-card 
          [title]="'總任務數'" 
          [total]="totalTasks()"
          contentHeight="46px"
        >
          <trend flag="up" style="margin-right: 16px;">
            <span>週成長</span><span>{{ weeklyGrowth() }}%</span>
          </trend>
        </chart-card>
      </div>
      
      <div nz-col [nzSpan]="24">
        <nz-card [nzTitle]="'任務狀態分佈'">
          <g2-bar 
            [data]="taskStatusData()"
            [height]="300"
            [padding]="[20, 40, 50, 60]"
          />
        </nz-card>
      </div>
      
      <div nz-col [nzSpan]="12">
        <nz-card [nzTitle]="'任務類型比例'">
          <g2-pie
            [data]="taskTypeData()"
            [height]="300"
            [hasLegend]="true"
            [inner]="0.6"
            [total]="totalTasks()"
          />
        </nz-card>
      </div>
    </div>
  `
})
export class DashboardComponent {
  private taskService = inject(TaskService);
  
  // Signals for reactive data
  tasks = this.taskService.tasks;
  
  totalTasks = computed(() => this.tasks().length);
  
  weeklyGrowth = computed(() => {
    // Calculate growth percentage
    const thisWeek = this.tasks().filter(t => 
      this.isThisWeek(t.createdAt)
    ).length;
    const lastWeek = this.tasks().filter(t => 
      this.isLastWeek(t.createdAt)
    ).length;
    
    return lastWeek > 0 ? 
      Math.round((thisWeek - lastWeek) / lastWeek * 100) : 0;
  });
  
  taskStatusData = computed(() => [
    { x: '待辦', y: this.tasks().filter(t => t.status === 'pending').length },
    { x: '進行中', y: this.tasks().filter(t => t.status === 'in-progress').length },
    { x: '已完成', y: this.tasks().filter(t => t.status === 'completed').length }
  ]);
  
  taskTypeData = computed(() => [
    { x: '設計', y: this.tasks().filter(t => t.type === 'design').length },
    { x: '開發', y: this.tasks().filter(t => t.type === 'development').length },
    { x: '測試', y: this.tasks().filter(t => t.type === 'testing').length }
  ]);
  
  private isThisWeek(date: Date): boolean {
    const now = new Date();
    const weekStart = new Date(now.setDate(now.getDate() - now.getDay()));
    return date >= weekStart;
  }
  
  private isLastWeek(date: Date): boolean {
    const now = new Date();
    const weekStart = new Date(now.setDate(now.getDate() - now.getDay() - 7));
    const weekEnd = new Date(now.setDate(now.getDate() - now.getDay()));
    return date >= weekStart && date < weekEnd;
  }
}

Best Practices

1. Use Signals for Reactive Charts

✅ DO:

chartData = computed(() => 
  this.tasks().map(t => ({ x: t.name, y: t.value }))
);

❌ DON'T:

chartData: any[] = [];
ngOnInit() {
  this.taskService.getTasks().subscribe(tasks => {
    this.chartData = tasks.map(t => ({ x: t.name, y: t.value }));
  });
}

2. Responsive Chart Heights

✅ DO:

@Component({
  template: `
    <g2-bar 
      [data]="data()"
      [height]="isMobile() ? 200 : 300"
    />
  `
})

3. Loading States

✅ DO:

@if (loading()) {
  <nz-spin nzSimple />
} @else if (chartData().length > 0) {
  <g2-bar [data]="chartData()" />
} @else {
  <nz-empty nzNotFoundContent="沒有資料" />
}

Performance Tips

1. Data Transformation: Transform data in computed signals, not in templates
2. Chart Reuse: Reuse chart components with different data props
3. Lazy Loading: Load chart module only when needed
4. Height Optimization: Use fixed heights for better performance
5. Data Limits: Limit chart data points (recommend < 100 for bar/pie)

Integration Checklist

• Install @delon/chart@20.1.0
• Import chart components in standalone components
• Use signals for reactive chart data
• Handle loading and empty states
• Set responsive chart heights
• Add proper TypeScript types for chart data
• Test with empty/large datasets
• Optimize data transformation with computed()

Anti-Patterns

❌ Mutating Chart Data Directly:

this.chartData.push({ x: 'new', y: 10 }); // Won't trigger change detection

✅ Use Signal Updates:

this.chartData.update(data => [...data, { x: 'new', y: 10 }]);

---

❌ Complex Logic in Templates:

<g2-bar [data]="tasks.filter(t => t.status === 'completed').map(t => ({x: t.name, y: t.value}))" />

✅ Use Computed Signals:

completedTasksData = computed(() => 
  this.tasks()
    .filter(t => t.status === 'completed')
    .map(t => ({ x: t.name, y: t.value }))
);

Cross-References

• ng-alain-component - ST Table for data tables
• delon-theme - Page layout and theme customization
• angular-component - Signals and computed for reactive charts
• .github/instructions/angular.instructions.md - Angular 20 patterns

Package Information

• Version: 20.1.0
• Repository: https://github.com/ng-alain/delon
• Documentation: https://ng-alain.com/chart

---

Version: 1.0
Created: 2025-12-25
Maintainer: ng-events(GigHub) Development Team