How does Stackoverflow remember what I entered in the input before I posted?

Question

When I start writing a question on Stackoverflow without finishing, I can leave the page, and when I return the input still is keeping what I had entered. How can this be done? Is a database absolutely necessary?

I would like to do something similar for a small webapp. Its a question-app where users answer questions with "No"/"Maybe"/"Yes". Depending on the answer, different points are awarded. When the user quits the test and returns, I would like to be still able to return the results of the last time he used it.

Can this be done completely in JavaScript?

What the test looks like

score 2 · Answer 1 · answered Mar 21 '18 at 07:25

2

You can store persistent information in localStorage - which is obviously local on the computer they're using.

Reference: https://developer.mozilla.org/en-US/docs/Web/API/Window/localStorage

answered Mar 21 '18 at 07:25

Jamiec

133,658
13
134
193

*Note* localStorage has ~10MB limit – Justinas Mar 21 '18 at 07:26
@Justinas true - but given the usecase here (3 yes/no/maybe questions) I'm hoping the OP doesnt even get close :) – Jamiec Mar 21 '18 at 07:27
Unless it is media files, to save just text ~10MB is alot :) – Suresh Atta Mar 21 '18 at 07:27
Side note: when using localStorage, always have a fallback mechanism if the localStorage is empty. – Ayush Gupta Mar 21 '18 at 07:30

score 0 · Answer 2 · edited Mar 22 '18 at 08:46

0

If you want this to across many systems/browser, you should use Database and store results and get back when access again.

If this feature restricted to the browser that you logged in, browsers localStorage alone will do the job.

Can this be done completely in JavaScript?

Yes if you are using localstorage.

edited Mar 22 '18 at 08:46

Ayush Gupta

8,716
8
59
92

answered Mar 21 '18 at 07:25

Suresh Atta

120,458
37
198
307

How does Stackoverflow remember what I entered in the input before I posted?

2 Answers2