Found pretty good script for showing recently viewed products using sessionStorage. There is only one problem: each product could be stored and showed multiple times.

Here is jsfiddle /

There should be one more IF to check if current product is already in storage, something like this:

// check if product already in storage
if(!productExistsInStorage()) {

    var currentCount = parseInt(sessionStorage.getItem("storedCount"));

    // add to storage
    sessionStorage.setItem(currentCount.toString(), JSON.stringify(productInfo()));

    // update storedCount var by one
    sessionStorage.setItem("storedCount", (currentCount + 1).toString());

}

I tried to make it, but without any success.

Any tips how not to save product data if it was already set in sessionStorage?

Found pretty good script for showing recently viewed products using sessionStorage. There is only one problem: each product could be stored and showed multiple times.

Here is jsfiddle http://jsfiddle/r77oozh8/

There should be one more IF to check if current product is already in storage, something like this:

// check if product already in storage
if(!productExistsInStorage()) {

    var currentCount = parseInt(sessionStorage.getItem("storedCount"));

    // add to storage
    sessionStorage.setItem(currentCount.toString(), JSON.stringify(productInfo()));

    // update storedCount var by one
    sessionStorage.setItem("storedCount", (currentCount + 1).toString());

}

I tried to make it, but without any success.

Any tips how not to save product data if it was already set in sessionStorage?

• javascript
• html
• local-storage
• session-storage

3 Answers 3

Just came across this post after I've looked it up myself.

if ("value" in sessionStorage) {
    alert("yes");
}
else {
    alert("no");
}

Instead of setting separate items in sessionStorage for each product, i would set them all in one array. That would make it easier to check if it already exists:

var currentItems = JSON.parse(sessionStorage.getItem('products'));
var currentProduct = productInfo();
if (currentItems.filter(function(p){return p.productURL == currentProduct.productURL}).length == 0) {
// add
}

Why not check is session storage for that item is null or not?

if(sessionStorage.getItem("storedCount") === null)
{
//do something
}

Even better make a function that you can pass the name of an item to to check it.

function doesStorageExist(item)
{

if(sessionStorage.getItem(""+item) === null)
{
//do something
}

}