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

import { IonicModule, IonicRouteStrategy } from '@ionic/angular';
import { SplashScreen } from '@ionic-native/splash-screen/ngx';
import { StatusBar } from '@ionic-native/status-bar/ngx';

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

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

import { Component } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { DomSanitizer } from '@angular/platform-browser';

@Component({
  selector: 'app-home',
  templateUrl: 'home.page.html',
  styleUrls: ['home.page.scss'],
})
export class HomePage {
  unsafeImageUrl:any;
  imageUrl:any;

  constructor(
    private http: HttpClient,
    private sanitizer:DomSanitizer)
  {
    this.hello();
  }

  hello(){
    this.http.get('http://127.0.0.1:5000',{responseType:'blob'})
     .subscribe(
       (res:any) => {
         console.log(res);
         this.unsafeImageUrl = URL.createObjectURL(res);
         this.imageUrl = this.sanitizer.bypassSecurityTrustUrl(this.unsafeImageUrl);
       })
  }
}

<ion-header [translucent]="true">
  <ion-toolbar>
    <ion-title>
      Blank
    </ion-title>
  </ion-toolbar>
</ion-header>

<ion-content [fullscreen]="true">
  <ion-header collapse="condense">
    <ion-toolbar>
      <ion-title size="large">Blank</ion-title>
    </ion-toolbar>
  </ion-header>

  <div id="container">
    <img [src]=imageUrl>
    <strong>Ready to create an app?</strong>
    <p>Start with Ionic <a target="_blank" rel="noopener noreferrer" href="https://ionicframework.com/docs/components">UI Components</a></p>
  </div>
</ion-content>

# -*- coding: utf-8 -*-
import io
import numpy as np
import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
from flask import Flask, send_file
from flask_cors import CORS
import json

app = Flask(__name__)
CORS(app)

@app.route('/',methods=["GET","POST"])
def hello():
    image = io.BytesIO()
    x = np.linspace(0, 10)
    y = np.sin(x)
    plt.plot(x, y)
    plt.savefig(image, format='png')
    image.seek(0)
    return send_file(image,
                     attachment_filename="image.png",
                     as_attachment=True)

if __name__ == "__main__":
    app.run(host='127.0.0.1',debug=True)