I am getting an error (ReferenceError:
localforage is not defined) when using the below code.
app.service('cacheService',
function () {
    return
{
        set: function
(key, value, expireTimeInSeconds) {
            return
localforage.setItem(key, {
                data: value,
                timestamp: new
Date().getTime(),
                expireTimeInMilliseconds:
expireTimeInSeconds * 1000
            })
        },
        get: function
(key) {
            return
localforage.getItem(key).then(function (item) {
                if
(!item || new Date().getTime() > (item.timestamp +
item.expireTimeInMilliseconds)) {
                    return null
                } else
{
                    return
item.data
                }
            })
        }
    }
});
Error:
 ReferenceError: localforage is not
defineds
We need to add localforage to our project as well: https://github.com/mozilla/localForage
angular-localforage is just the angular wrapper.
We need to add localforage to our project as well: https://github.com/mozilla/localForage
angular-localforage is just the angular wrapper.
Solution
1:  To use
localForage, just drop a single JavaScript file into your page:
<script src="localforage/dist/localforage.js"></script>
<script>localforage.getItem('something', myCallback);</script>
Solution
2: 
Download the latest localForage from GitHub, or
install with npm:
npm install localforage
Solution
3: 
Add the reference on the HTML page,
<script src="https://cdn.rawgit.com/mozilla/localForage/master/dist/localforage.js"></script>
Live example,
https://codepen.io/thgreasi/pen/ojYKeE