如何在Javascript中的多个浏览器中获得相同的值？

Question

I'm working on a section for a web page that allows the user to see when the page was last updated.

The way it's supposed to work is I choose a date in the first input box and click the update button and the second box fill the the Last Updated field with the date and the time.

After that, I should be able to exit out of the page and when I reopen the page Last Updated field should be filled with the same date and time until I change it.

I'm able to see that my code does still show the date that I have added in the last time I was on e the page, the problem I'm having is I want the result to be the same regardless of what browser I'm using it on.

For example if the date is 2020-09-15T13:53 on Chrome I want the resulting date to be 2020-09-15T13:53 on Edge, Safari and Firefox as well. Of I go on Edge and open my page there it would show nothing or another date when I edited on Edge.

Here's my code:

    <div class="last-update-header">
        <h3> New Update Date: <input type="datetime-local" id="update" name="update-start" value="yyyy-mm-dd hh:mm"/> </h3>
        <h3> Last Updated: <input type="label; submit" id="lastUpdate"  readonly="readonly"/> </h3>
        <button id="updateButton" onclick="myFunction(); saveValue(lastUpdate)"> Update </button>
        <script>
            document.getElementById("lastUpdate").value = getSavedValue("lastUpdate");
            function myFunction(e) {
                document.getElementById("lastUpdate").value = document.getElementById("update").value;
            }
            function saveValue(e) {
                var id = e.id;
                var val = e.value;
                localStorage.setItem(id, val);
            }
            function getSavedValue(v) {
                if (!localStorage.getItem(v)) {
                    return "";
                }
                return localStorage.getItem(v);
            }
        </script>
    </div>

My question is how can I get this code where I can read the same output on all browsers and from multiple computers and not different things for different browsers?

Answer 1

You'll need to save it on the server somewhere. Even if localStorage worked across different browsers (it doesn't) that would only be saved on your machine, others wouldn't be able to see it.

You're probably making it unnecessarily complicated using JavaScript at all. You could just update the HTML to reflect the last updated time.

If you really want it to work the way you've requested you'll need to use a server-side language on-top of the JavaScript but you'd also need to rewrite all of that.