CODEWITHSUNDEEP
jquerylocal-storagedefault-value
daGUY
daGUY

Reputation: 28793

jQuery Storage: set default value if stored value is NaN

I'm using jQuery Storage to save and restore a user's set volume level for a music player. Whenever they drag the volume slider, I save the value...

this.setVolume = function(volume) {
    ...
    $.Storage.set('volume', volume + '');
    ...
};

Then I use that value as the initial value for the slider the next time the page is loaded...

$("#volumeslider").slider({
    ...
    value: volume,
    ...
});

The saving and restoring part works fine. The problem is, if you're a brand new user and haven't yet adjusted the volume slider, volume doesn't have a value.

So I tried using a try/catch block to set the volume at 0.6 by default, unless there was a saved value to restore:

var volume = 0.6;
try {
    volume = parseFloat($.Storage.get('volume'));
} catch (e) { }

But instead, volume comes back as NaN. Then I realized that there's no "error" to catch because NaN is simply the result of parseFloat on the empty value in storage.

So: how would I set a default value only for when there's nothing in storage?

Upvotes: 0

Views: 2087

Answers (3)

daGUY
daGUY

Reputation: 28793

A cleaner solution than my original answer:

var volume = parseFloat($.Storage.get('volume'));
if (!volume) {
    volume = 0.6;
    $.Storage.set('volume', volume + '');
}

Use a stored value if it exists; if not, set a default value and store that instead.

Upvotes: 0

daGUY
daGUY

Reputation: 28793

Solved it using this question as a reference:

if (!isNaN(parseFloat($.Storage.get('volume')))){
    var volume = parseFloat($.Storage.get('volume'));
} else {
    var volume = 0.6;
}

Upvotes: 1

Andreas
Andreas

Reputation: 21911

Why are you storing the value as string to convert it back to a number?
Nevertheless

$("#volumeslider").slider({
    value: parseFloat($.Storage.get("volume") || 0.6),
});

Upvotes: 3

Related Questions