CODEWITHSUNDEEP
javascripthtml
user3464627
user3464627

Reputation: 55

If localstorage empty do nothing. If not, do something

Would I be able to create a function that automatically runs when something is put into localstorage?

I tried to come up with something myself but it doesn't seem to work.

function () {
    if (localStorage.value == ""){
        //do nothing
    }
    else {
        document.getElementById("test").innerHTML = "" + (localStorage.getItem("server")) + ""  ;
    }
}

Edit: This bit of code works, but it doesn't update itself, so if I enter a new value into localstorage, this code won't pick it up and will display the old value still.

if (localStorage.length == 0){   
    document.getElementById("test").innerHTML = "Please go back and enter your name.";
}
else {
    document.getElementById("test").innerHTML = "" + (localStorage.getItem("server")) + ""  ;
}

Upvotes: 0

Views: 865

Answers (3)

user3464627
user3464627

Reputation: 55

I managed to use setInterval to refresh itself.

if (localStorage.length == 0){
    document.getElementById("test").innerHTML = "Please go back and enter your name.";
}
else {
    var myVar = setInterval(function(){myTimer()}, 1000);
    function myTimer() {
        var nameprint = document.getElementById("test").innerHTML ="" + (localStorage.getItem("server")) + "";
    }
}

Upvotes: 0

Rob M.
Rob M.

Reputation: 36511

If you wrote a wrapper around localStorage and used that instead set you could run a callback when a value is set

var storage = {
   get: function(key){
      return localStorage.getItem(key);
   },
   set: function(key, value, callback){
      localStorage.setItem(key, value);
      if(typeof(callback) === 'function'){
          callback.call(null, value);
      }
   }
}

storage.set('user', "John Smith", function(value){
    console.log("You set your username to %s", value);
});

Upvotes: 1

Lorenz Meyer
Lorenz Meyer

Reputation: 19915

This is the way to find out if localstorage is empty. 

if (localStorage.length == 0){ ...

Upvotes: 0

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