How to return the result of this function

Ionic Framework ionic-v3
21

how to call test() function could you put code here and also how to print result

22

@AaronSterling please I do not master the Promise can make an example for my case

23

Are currencies and val both type number? (I.e. currencies array stores numbers)

24

My provider class

 import {Injectable} from '@angular/core';
import {Storage} from '@ionic/storage';
import {AlertController, Events} from 'ionic-angular';
import {Const} from "../../app/app.global";
import {HttpClient, HttpParams} from "@angular/common/http";
import {ToastProvider} from "../boutique/toast/toast";
import {FileTransfer, FileTransferObject, FileUploadOptions} from "@ionic-native/file-transfer";
import {OutilProvider} from "../outil/outil";


@Injectable()
export class UserProvider {
    private USER_KEY: string = 'user';
    private CURENT_CURRENCY_KEY: string = 'currency';
    private CURRENCES_KEY: string = 'currenceis';

    user: any = {};
    private static result: any = 0;

    constructor(private transfer: FileTransfer, public storage: Storage,
                public events: Events, private outil: OutilProvider, private alertCtrl: AlertController,
                private http: HttpClient, private toas: ToastProvider) {
        this.load();
    }

    load() {
        return this.storage.get(this.USER_KEY).then((val) => {
            if (val)
                this._loggedIn(val, 0);
        });
    } 
    setCurrentcurrency(data) {
        this.storage.set(this.CURENT_CURRENCY_KEY, data);
        this.http.get(Const.url + '/?currency=' + data).subscribe(res => {
        });
        this.storage.set(this.CURENT_CURRENCY_KEY, data);
    }


    getCurrentCurrency() {
        return this.storage.get(this.CURENT_CURRENCY_KEY);
    }


    updateCurrency() {
        let cookie = this.user.cookie;
        this.http.get(Const.url + '/api/user/getcurrency/?insecure=cool&cookie=' + cookie).subscribe(val => {
            this.storage.set(this.CURRENCES_KEY, val);
        });
    }


    changeCurrentCurrency(value: number):Promise<any>{
        return new Promise(resolve => {
            this.getCurrency().then((currencies) => {
                this.getCurrentCurrency().then((val) => {
                    let    res = value * currencies[val]['rate'];
                    return res;
                });
            });
        });

    }
 
}

My pipe class

import {Pipe, PipeTransform} from '@angular/core';
import {CurrencyPipe} from '@angular/common';
import {SettingsProvider} from '../../providers/providers';
import {Storage} from "@ionic/storage";
import {UserProvider} from "../../providers/user/user";

@Pipe({
    name: 'money',
})
export class MoneyPipe implements PipeTransform {
    app: any = {};
    current;

    constructor(public setting: SettingsProvider, private user: UserProvider) {
        this.setting.load().then(x => {
            if (x) this.app = x.settings;
        })

    }


    transform(value, app) {
        let x = app || this.setting.all.settings;
      this.user.changeCurrentCurrency(value).then((res) => { 
         console.log(res); 
       }); 
        return new CurrencyPipe(x.currency).transform(value, x.currency, 'symbol-narrow', '1.' + x.number_of_decimals + '-' + x.number_of_decimals, 'fr');
    }
}
25

val is string example EUR

currencies is a json EUR is a key currencies example
EUR :{name: "EUR", rate: 1, symbol: "&euro;", position: "right_space", is_etalon: 1, hide_cents: 0,…}

26

Create a formal type for it. There are a lot of issues in your code, but you can fix a lot of them if you step back and define a type for every variable. Also, don’t use var. Use let. Only use var if you understand the difference and are in a special situation where var is better. Then


test(value: TypeOfValue): Promise<number> {
   let currencies = this.storage.get('age');
   let betterVariableNameThanVal = this.getCurrentCurrency();
   return Promise.all(currencies, betterVariableNameThanVal)
                 .then(resultArray => value * resultArray[0][resultArray[1]]['rate']);
}
27

@AaronSterling Promise.all asks me for an argument
return Promise.all (currencies, betterVariableNameThanVal
.then(resultArray => value * resultArray[0][resultArray[1]][‘rate’]);

28

Look for typos…

29

Good @AaronSterling your solution ist correct thanks. youare forget Promise.all()

30

Good evening my friends please I need your help on the promised I still have problems, I want to execute the function changeCurrentCurrency in my pipe class and back the result but since nothing at all:

  • My provider class
import {Injectable} from '@angular/core';
import {Storage} from '@ionic/storage';
import {AlertController, Events} from 'ionic-angular';
import {Const} from "../../app/app.global";
import {HttpClient, HttpParams} from "@angular/common/http";
import {ToastProvider} from "../boutique/toast/toast";
import {FileTransfer, FileTransferObject, FileUploadOptions} from "@ionic-native/file-transfer";
import {OutilProvider} from "../outil/outil";


@Injectable()
export class UserProvider {
    private USER_KEY: string = 'user';
    private CURENT_CURRENCY_KEY: string = 'currency';
    private CURRENCES_KEY: string = 'currenceis';

    user: any = {};
    constructor(private transfer: FileTransfer, public storage: Storage,
                public events: Events, private outil: OutilProvider, private alertCtrl: AlertController,
                private http: HttpClient, private toas: ToastProvider) {
        this.load();
    }

    load() {
        return this.storage.get(this.USER_KEY).then((val) => {
            if (val)
                this._loggedIn(val, 0);
        });
    }

    _loggedIn(user, index) {
        this.user = user; 
        this.events.publish('user:login', {tabIndex: index});
        return this.user;
    }
 
    setCurrentcurrency(data) {
        this.storage.set(this.CURENT_CURRENCY_KEY, data);
        this.http.get(Const.url + '/?currency=' + data).subscribe(res => {
        });
        this.storage.set(this.CURENT_CURRENCY_KEY, data);
    }


    getCurrentCurrency() {
        return this.storage.get(this.CURENT_CURRENCY_KEY);
    }


    updateCurrency() {
        let cookie = this.user.cookie;
        this.http.get(Const.url + '/api/user/getcurrency/?insecure=cool&cookie=' + cookie).subscribe(val => {
            this.storage.set(this.CURRENCES_KEY, val);
        });
    }


    changeCurrentCurrency(value: number): Promise<number> {
        let currencies = this.getCurrency();
        let betterVariableNameThanVal = this.getCurrentCurrency();
        return Promise.all([currencies, betterVariableNameThanVal])
            .then(resultArray => value * resultArray[0][resultArray[1]]['rate']);
    } 
 

}

-My pipe classe

import {Pipe, PipeTransform} from '@angular/core';
import {CurrencyPipe} from '@angular/common';
import {SettingsProvider} from '../../providers/providers';
import {Storage} from "@ionic/storage";
import {UserProvider} from "../../providers/user/user";

@Pipe({
    name: 'money',
})
export class MoneyPipe implements PipeTransform {
    app: any = {};
    current;

    constructor(public setting: SettingsProvider, private user: UserProvider) {
        this.setting.load().then(x => {
            if (x) this.app = x.settings;
        })

    }


    transform(value:number, app) {
        let x = app || this.setting.all.settings;
        this.user.changeCurrentCurrency(value).then((val => {
          return      new CurrencyPipe(x.currency).transform(val, x.currency, 'symbol-narrow', '1.' + x.number_of_decimals + '-' + x.number_of_decimals, 'fr');

        }));
     }
}

Thanks @AaronSterling @addwebsolution @pwespi @anna_liebt