react-native动态获取/设置配置变量（API URL）

Question

My app starts by choosing a country and I want to change my API_URL according to the country data a user selects.

My country_id is stored in AsyncStorage. I have tried this but is has not worked.

function Configure() {
    let url = '';
}
Configure.prototype.getApiUrl = function (params = null) {
    AsyncStorage.getItem("country").then((value) => {
        if(value == 223) {
            return "https://www.website.com/usa_api"
        }else{
            return "https://www.website.com/api"
        }
    });
}

module.exports = Configure

Answer 1

You have to return the Promise function

function Configure() {
    let url = '';
}

Configure.prototype.getApiUrl = function (params = null) {
    return AsyncStorage // Have to return the promise
        .getItem("country")
        .then((value) => {
            if (value == 223) {
                return "https://www.website.com/usa_api"
            } else {
                return "https://www.website.com/api"
            }
        });
}

module.exports = Configure

Usage

Now that we are returning the Promise, we can await it from where you want to use it

// Use the promise
Configure
  .getApiUrl()
  .then((apiURL) => {
      // You should be getting the API URL here
  })


// Or better looking code with async/await
const apiURL = await Configure.getApiUrl();
// You should be getting the API URL here