Date formatting using luxon
The default rendering of dates from our models is very ugly: Mon Apr 10 2020 15:49:58 GMT+1100 (AUS Eastern Daylight Time). In this section we'll show how you can update the BookInstance List page from the previous section to present the due_date field in a more friendly format: Apr 10th, 2023.
The approach we will use is to create a virtual property in our BookInstance model that returns the formatted date. We'll do the actual formatting using luxon, a powerful, modern, and friendly library for parsing, validating, manipulating, formatting and localising dates.
Note:
It is possible to use luxon to format the strings directly in our Pug templates, or we could format the string in a number of other places. Using a virtual property allows us to get the formatted date in exactly the same way as we get the due_date currently.
Install luxon
Enter the following command in the root of the project:
npm install luxon
Create the virtual property
-
Open ./models/bookinstance.js.
-
At the top of the page, import luxon.
jsconst { DateTime } = require("luxon");
Add the virtual property due_back_formatted just after the URL property.
BookInstanceSchema.virtual("due_back_formatted").get(function () {
return DateTime.fromJSDate(this.due_back).toLocaleString(DateTime.DATE_MED);
});
Note:
Luxon can import strings in many formats and export to both predefined and free-form formats. In this case we use fromJSDate() to import a JavaScript date string and toLocaleString() to output the date in DATE_MED format in English: Apr 10th, 2023.
For information about other formats and date string internationalization see the Luxon documentation on formatting.
Update the view
Open /views/bookinstance_list.pug and replace due_back with due_back_formatted.
if val.status != 'Available'
//span (Due: #{val.due_back} )
span (Due: #{val.due_back_formatted} )
That's it. If you go to All book-instances in the sidebar, you should now see all the due dates are far more attractive!
Next steps
- Return to Express Tutorial Part 5: Displaying library data.
- Proceed to the next subarticle of part 5: Author list page and Genre list page challenge.