utils.js

// obtained from react native tutorials

import React from "react";
import { PixelRatio } from "react-native";
import Dimensions from "Dimensions";

const Util = {
  ratio: PixelRatio.get(),
  pixel: 1 / PixelRatio.get(),
  size: {
    width: Dimensions.get("window").width,
    height: Dimensions.get("window").height
  },
  post(url, data, callback) {
    const fetchOptions = {
      method: "POST",
      headers: {
        Accept: "application/json",
        "Content-Type": "application/json"
      },
      body: JSON.stringify(data)
    };

    fetch(url, fetchOptions)
      .then(response => {
        return response.json();
      })
      .then(responseData => {
        callback(responseData);
      });
  },
  key: "BDKHFSDKJFHSDKFHWEFH-REACT-NATIVE"
};

export default Util;