Angularでリアルタイムに変化するグラフを書く

リアルタイムにデータが移り変わるグラフです．

realtime-streaming-data-with-angular-chartjs

概要

Angularでリアルタイムにデータが移り変わるグラフを作成します．

プロジェクトの作成

% ionic start app-name-streaming tabs --type=angular

プラグインのインストール

npm install ng2-charts@2 chartjs-plugin-streaming@1 --save
npm install chart.js@2.9.3 --save

プラグインの設定

app.module.tsで設定します．

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { RouteReuseStrategy } from '@angular/router';

import { IonicModule, IonicRouteStrategy } from '@ionic/angular';

import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';

+import { ChartsModule } from 'ng2-charts';

@NgModule({
  declarations: [AppComponent],
  entryComponents: [],
  imports: [
    BrowserModule,
    IonicModule.forRoot(),
    AppRoutingModule,
+    ChartsModule
  ],
  providers: [{ provide: RouteReuseStrategy, useClass: IonicRouteStrategy }],
  bootstrap: [AppComponent],
})
export class AppModule {}

リアルタイムに変化するグラフをかく

今回はIonicのタブプロジェクトのtab2に追加します．まずtab2.page.moduleにChartModuleを登録します．

import { IonicModule } from '@ionic/angular';
import { RouterModule } from '@angular/router';
import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { FormsModule } from '@angular/forms';
import { Tab2Page } from './tab2.page';
import { ExploreContainerComponentModule } from '../explore-container/explore-container.module';

import { Tab2PageRoutingModule } from './tab2-routing.module';
+import { ChartsModule } from 'ng2-charts';

@NgModule({
  imports: [
    IonicModule,
    CommonModule,
    FormsModule,
    ExploreContainerComponentModule,
    Tab2PageRoutingModule,
+    ChartsModule
  ],
  declarations: [Tab2Page]
})
export class Tab2PageModule {}

次にtab2.page.tsとtab2.page.htmlを編集します．

import { Component } from '@angular/core';
import 'chartjs-plugin-streaming';

@Component({
  selector: 'app-tab2',
  templateUrl: 'tab2.page.html',
  styleUrls: ['tab2.page.scss']
})
export class Tab2Page {

  myDataFromServer:number=20;
  updateMyDataFromServerFunction:any;

  datasets: any[] = [{
    data: []
  }, {
    data: []
  }];

  options: any;
  constructor( ) {}

  ngOnInit(){

    this.options= {
      scales: {
        xAxes: [{
          type: 'realtime',
          realtime: {
            onRefresh: (chart: any) =>{
              chart.data.datasets.forEach((dataset: any) => {  
                dataset.data.push({
                  x: Date.now(),
                  y:this.myDataFromServer
                });
              });
            },
            delay: 2000
          }
        }],
        yAxes: [{
          ticks: {
            max:100,
            min:0
          }
        }]
      }
    };
    this.updateMyDataFromServer();
  }

  updateMyDataFromServer(){
    console.log('updateMyDataFromServer() called');    
    this.updateMyDataFromServerFunction = setInterval(() => {
      console.log('called');
      this.myDataFromServer = Math.random() * 100;
      console.log(this.myDataFromServer,'this.myDataFromServer');
    },1000)
  }
}

リアルタイムに描写されるグラフが作成できました．

環境詳細

{
  "name": "1206_scrach_image",
  "version": "0.0.1",
  "author": "Ionic Framework",
  "homepage": "https://ionicframework.com/",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular/common": "~12.0.1",
    "@angular/core": "~12.0.1",
    "@angular/forms": "~12.0.1",
    "@angular/platform-browser": "~12.0.1",
    "@angular/platform-browser-dynamic": "~12.0.1",
    "@angular/router": "~12.0.1",
    "@ionic/angular": "^5.5.2",
    "@nebulae/angular-ble": "^1.0.6",
    "@types/web-bluetooth": "0.0.9",
    "aes-js": "^3.1.2",
    "chart.js": "^2.9.3",
    "chartjs-plugin-streaming": "^1.9.0",
    "ng2-charts": "^2.4.2",
    "rxjs": "~6.6.0",
    "tslib": "^2.0.0",
    "zone.js": "~0.11.4"
  },
  "devDependencies": {
    "@angular-devkit/build-angular": "~12.0.1",
    "@angular-eslint/builder": "~12.0.0",
    "@angular-eslint/eslint-plugin": "~12.0.0",
    "@angular-eslint/eslint-plugin-template": "~12.0.0",
    "@angular-eslint/template-parser": "~12.0.0",
    "@angular/cli": "~12.0.1",
    "@angular/compiler": "~12.0.1",
    "@angular/compiler-cli": "~12.0.1",
    "@angular/language-service": "~12.0.1",
    "@ionic/angular-toolkit": "^4.0.0",
    "@types/jasmine": "~3.6.0",
    "@types/jasminewd2": "~2.0.3",
    "@types/node": "^12.11.1",
    "@typescript-eslint/eslint-plugin": "4.16.1",
    "@typescript-eslint/parser": "4.16.1",
    "eslint": "^7.6.0",
    "eslint-plugin-import": "2.22.1",
    "eslint-plugin-jsdoc": "30.7.6",
    "eslint-plugin-prefer-arrow": "1.2.2",
    "jasmine-core": "~3.7.1",
    "jasmine-spec-reporter": "~5.0.0",
    "karma": "~6.3.2",
    "karma-chrome-launcher": "~3.1.0",
    "karma-coverage": "~2.0.3",
    "karma-coverage-istanbul-reporter": "~3.0.2",
    "karma-jasmine": "~4.0.0",
    "karma-jasmine-html-reporter": "^1.5.0",
    "protractor": "~7.0.0",
    "ts-node": "~8.3.0",
    "typescript": "~4.2.4"
  },
  "description": "An Ionic project"
}