React Native + Javascript + Date Time + JSON.Stringify() + JSON.parse()

This page will capture all issues related to Date and React Native mobile app development. Will add more as I go through the development cycle. 

I will play around with Javascript for a bit before switching to TypeScript. 

Some of the information below might not be following the best practice as I just started the development process. Will update as I learn more about React Native + Javascript.

Storing Date object in AsyncStorage

You can store Date object directly into AsyncStorage. Generally in other programming language, you can store the Date object directly in a data storage. However, with React Native, you will get the the Debug Console warning on Expo Go if you do so. I recommend using JSON.stringify() command below to store the date object. Please follow the instruction below. 

On the side note, you can also store millisecond and use the date toString option but it is not recommended. I would recommend using stringify command as it will store using the toISOString() which is the ISO 8601 string format.

Prior to storing a date object in AsyncStorage, convert it to string first before you store it. Use JSON.stringify() command.

Example code:

await AsyncStorage.setItem('selectedDate', JSON.stringify(newDate));

Retrieve From AsyncStorage

retrieveDate = async () => {

    const stringifiedObject = await AsyncStorage.getItem('date'); 

    let newDate = new Date(Date.parse(JSON.parse(stringifiedObject)));

}; 

JSON.stringify() - Date double quote issue

When you use stringify on a date object, this command will add double quote (") around your date attribute. If you use the Date.parse(stringifiedObject) command here, you will get an Invalid Date error.

There are 2 options:

1. Before you use Date.parse command to change it back to a date object, make sure you remove the double quote; or,

2. The better option is to use the command: new Date(Date.parse(JSON.parse(stringifiedObject)))

So yes, I recommend the following option to create a date option out of a stringified date:

let sampleDate = new Date(Date.parse(JSON.parse(stringifiedObject)));