Error when attempting to import 'fs' into .ts file

Ionic Framework ionic-v3
#1

I’m building an app that uses currency exchange rates. I was attempting to set variables from values in a json file using the following:

import * as fs from 'fs';

export class CurrencyConverter {

  private rates: any;
  private usdtoeur: number;

  constructor() {
    this.rates = fs.readFileSync('./assets/oxr.json'); 
    this.usdtoeur = this.rates.EUR;
  }
}

for some reason I keep on getting the following error:
[ts] Cannot find module 'fs'.

I have updated all of my node modules to their compatible versions and this still has not fixed the problem.
Anyone know what is going wrong here?

#2

What is fs supposed to do?? Support filesystem stuff? Then use File instead

Isnt fs a nodejs server side thing?

If it isnt, then it is good to know your package.json and see how you added this as module

#3

Use the File plugin from Ionic Native.
Using the filesystem module won’t work in an app.

#4

ok thank you both! I’ll read up on File and see if I can implement it

#5

@MattE after importing File and adding it to my constructor like so:

import { File } from '@ionic-native/file';

constructor(public navCtrl: NavController, private file: File) {
    
  }

I get the following error:

ERROR Error: Uncaught (in promise): Error: StaticInjectorError[File]: 
  StaticInjectorError[File]: 
    NullInjectorError: No provider for File!
Error: StaticInjectorError[File]: 
  StaticInjectorError[File]: 
    NullInjectorError: No provider for File!
    at _NullInjector.get (core.js:993)
    at resolveToken (core.js:1281)
    at tryResolveToken (core.js:1223)
    at StaticInjector.get (core.js:1094)
    at resolveToken (core.js:1281)
    at tryResolveToken (core.js:1223)
    at StaticInjector.get (core.js:1094)
    at resolveNgModuleDep (core.js:10878)
    at NgModuleRef_.get (core.js:12110)
    at resolveDep (core.js:12608)
    at _NullInjector.get (core.js:993)
    at resolveToken (core.js:1281)
    at tryResolveToken (core.js:1223)
    at StaticInjector.get (core.js:1094)
    at resolveToken (core.js:1281)
    at tryResolveToken (core.js:1223)
    at StaticInjector.get (core.js:1094)
    at resolveNgModuleDep (core.js:10878)
    at NgModuleRef_.get (core.js:12110)
    at resolveDep (core.js:12608)
    at c (polyfills.js:3)
    at c (polyfills.js:3)
    at polyfills.js:3
    at t.invokeTask (polyfills.js:3)
    at Object.onInvokeTask (core.js:4744)
    at t.invokeTask (polyfills.js:3)
    at r.runTask (polyfills.js:3)
    at o (polyfills.js:3)
    at <anonymous>
#6

You need to import and add File to your list of providers in app.module.ts.

1 Like
#7

@SigmundFroyd awesome thanks that worked

#8

where would I find the reference to the json file I’m trying to import data from?
The file is oxr.json and is located at /assets/oxr.json.

I’m using the following command to test if it can find a file but it is outputting nothing.

console.log("dir: "+this.file.readAsText(this.file.dataDirectory + "/assets/", "oxr.json"));
#9

Better use http for json ans other stuff in assets folder

http.get(’/assets/etc’)

#10

Hi @MattE I need to know how to or what to use for encryption & decryption of files using ionic cordova file plugin ?

thanks in advance

#11