Geolocation and Popups

Geolocation and Popups

Two more handy browser APIs: finding location and showing message boxes.

Geolocation

navigator.geolocation finds the user's position (with permission):

navigator.geolocation.getCurrentPosition(
  function(position) {
    console.log(position.coords.latitude);
    console.log(position.coords.longitude);
  },
  function(error) {
    console.log("Location denied");
  }
);

Popup boxes

JavaScript has three built-in dialogs:

• alert(): a message box with OK.
• confirm(): asks OK or Cancel, returns true/false.
• prompt(): asks for text input.

alert("Hello");
let ok = confirm("Are you sure?");
let name = prompt("What is your name?");

When to use popups

Popups block the page and can be annoying, so use them sparingly. Custom dialogs and forms are usually nicer.

The navigator object

navigator describes the browser and system:

navigator.userAgent;
navigator.language;

TL;DR

• Geolocation gets the user's position with permission.
• alert, confirm, and prompt are built-in popups.
• Use popups sparingly.
• navigator describes the browser.