According to [this site](http://www.nczonline.net/blog/2009/07/21/introduction-to-sessionstorage/), Firefox’s and Safari’s storage limit is 5MB per domain, Internet Explorer’s limit is 10 MB per domain.



However, according to [this site which tests your web browser local storage capabilities](http://dev-test.nemikor.com/web-storage/support-test/), on my machine:

    Browser        LocalStorage         SessionStorage
    -------        ------------         --------------
    Chrome              5M                   5M
    Firefox             5M                Unlimited
    IE11                5M                   5M

Also, note the handy chart at the bottom of the page.


The amount able to be stored varries from browser to browser with IE being able to store up to a couple MB. It is also good to note that there is a vulnerabilty that allows an unlimited amount of data to be stored.

The Dart language does not have enums (yet??). What is the proper or idiomatic way to construct an enum, at least until a language feature arrives?

How can I build an enum with Dart?

When I draw a shape using:

    canvas.create_rectangle(10, 10, 50, 50, color=&quot;green&quot;)

Does Tkinter keep track of the fact that it was created? 

In a simple game I&#39;m making, my code has one `Frame` create a bunch of rectangles, and then draw a big black rectangle to clear the screen, and then draw another set of updated rectangles, and so on. 

Am I creating thousands of rectangle objects in memory? 

I know you can assign the code above to a variable, but if I don&#39;t do that and just draw directly to the canvas, does it stay in memory, or does it just draw the pixels, like in the HTML5 canvas?

How to clear Tkinter Canvas?

Although the [size of localStorage](https://stackoverflow.com/questions/2989284) has been addressed in detail and there is a [online test for it](http://arty.name/localstorage.html), I was wondering what the maximum size of [sessionStorage](https://developer.mozilla.org/en-US/docs/DOM/Storage#sessionStorage) is for the common browsers?

How large is HTML5 session storage?

<p>Although the <a href="https://stackoverflow.com/questions/2989284" target="_blank" rel="noopener noreferrer">size of localStorage</a> has been addressed in detail and there is a <a href="http://arty.name/localstorage.html" target="_blank" rel="noopener noreferrer">online test for it</a>, I was wondering what the maximum size of <a href="https://developer.mozilla.org/en-US/docs/DOM/Storage#sessionStorage" target="_blank" rel="noopener noreferrer">sessionStorage</a> is for the common browsers?</p>


I am Javascript beginner.

I am initing web page via the `window.onload`, I have to find bunch of elements by their class name (`slide`) and redistribute them into different nodes based on some logic. I have function `Distribute(element)` which takes an element as input and does the distribution. I want to do something like this (as outlined for example [here][1] or [here][2]):

    var slides = getElementsByClassName(&quot;slide&quot;);
    for(var i = 0; i &lt; slides.length; i++)
    {
       Distribute(slides[i]);
    }

however this does not do the magic for me, because `getElementsByClassName` does not actually return array, but a [`NodeList`][3], which is... 

**...this is my speculation...**

...being changed inside function `Distribute` (the DOM tree is being changed inside this function, and cloning of certain nodes happen). `For-each` loop structure does not help either.

The variable slides act&#39;s really un-deterministicaly, through every iteration it changes it&#39;s length and order of elements wildly.


What is the correct way to iterate through NodeList in my case? I was thinking about filling some temporary array, but am not sure how to do that...

**EDIT:**
---------

 

important fact I forgot to mention is that there might be one slide inside another, this is actually what changes the `slides` variable as I have just found out thanks to user [Alohci][4].

The solution for me was to clone each element into an array first and pass the array ono-by-one into `Distribute()` afterwards.


  [1]: https://stackoverflow.com/questions/5179798/javascript-getelementsbyclassname-always-returns-none
  [2]: https://stackoverflow.com/questions/3871547/js-iterating-over-result-of-getelementsbyclassname-using-array-foreach
  [3]: https://developer.mozilla.org/en-US/docs/DOM/NodeList
  [4]: https://stackoverflow.com/users/42585/alohci

How to correctly iterate through getElementsByClassName

Is there any difference between `typeof (myVariable)` compared to `typeof myVariable`? 

Both work, but coming from PHP, I don&#39;t understand why this function can use parenthesis or not. 



Why does &quot;typeof&quot; not need parentheses?

How to make a `div` remain fixed after you scroll to that `div`? I have a `div` that is later in a page and you need to scroll to get to that `div`.

If I use:

    .divname {
      position: fixed;
    }

The `div` will appear before it should appear normally. Maybe a good example of what I need is second ad on [9gag][1]. If your screen resolution is low enough, you won&#39;t see that ad after you load the front page, but after you scroll down, you&#39;ll see the second ad and it will remain fixed while you scroll down.

  [1]: https://9gag.com/

How to make div fixed after you scroll to that div?

How can one remove a whole IndexedDB database from JavaScript, as opposed to just an object store? I&#39;m using the [IndexedDB shim](http://nparashuram.com/IndexedDBShim/), which may use WebSQL as its backend.

I&#39;d mainly like to know how to do this for the PhantomJS (headless) browser, although Chrome, Safari (on iPad) and IE10 are other important browsers.

How can I remove a whole IndexedDB database from JavaScript?

I want to use the `filter` in angular and want to filter for multiple values, if it has either one of the values then it should be displayed.

I have  for example this structure: 

An object `movie` which has the property `genres` and I want to filter for `Action` and `Comedy`.

I know I can do `filter:({genres: &#39;Action&#39;} || {genres: &#39;Comedy&#39;})`, but what to do if I want to filter it dynamically. E.g. `filter: variableX`

How do I set `variableX` in the `$scope`, when I have an array of the genres I have to filter?

I could construct it as a string and then do an `eval()` but I don&#39;t want to use eval()...

How to filter multiple values (OR operation) in angularJS

I want an optional line-breaking character that is always invisible that works with the `word-wrap: break-word;` CSS style.

Here are some specifics. My goal is to break apart long links in reasonable places. These characters are a good place to start: `-`, `.`, `_`, `/`, `\`. This is not a Rails-specific question, but I wanted to share some code I&#39;m using now:

    module ApplicationHelper
      def with_optional_line_breaks(text)
        text.gsub(%r{([-._/\\])}, &#39;\1&amp;shy;&#39;)
      end
    end

Here&#39;s the problem with the code above: when `&amp;shy;` takes effect (in a table with: `word-wrap: break-word;`), `&amp;shy;` gets displayed as `-`. I don&#39;t want to see the `-`; I want a line break without any character shown.




----------

Optional line-breaking HTML entity that is always invisible

I&#39;m looking to set a parent DIV as 70% of the full 100% screen height. I&#39;ve set the following CSS but it doesn&#39;t seem to do anything:

    body {
	font-family: &#39;Noto Sans&#39;, sans-serif;
	margin: 0 auto;
	height: 100%;
	width: 100%;
    }
    .header {
	height: 70%;
    }

For some reason it doesn&#39;t seem to be working though and the header isn&#39;t 70% of the screen size. Any advice?

DIV height set as percentage of screen?

Why this does not work ? 

    if(typeof(localStorage.getItem(&quot;username&quot;))==&#39;undefined&#39;){
    	alert(&#39;no&#39;);
    };

The goal is to redirect the user from the index page to the login page if not already logged.
Here the `localStorage.getItem(&quot;username&quot;))` variable is not defined for the moment.

It&#39;s for an ios phonegap app.


HTML5 LocalStorage: Checking if a key exists

I know there has been many questions about checking for `localStorage` but what if someone manually shuts it off in their browser?  Here&#39;s the code I&#39;m using to check:

    localStorage.setItem(&#39;mod&#39;, &#39;mod&#39;);
	if (localStorage.getItem(&#39;mod&#39;) != null){
	  alert (&#39;yes&#39;);
	  localStorage.removeItem(&#39;mod&#39;);
	} else {
      alert (&#39;no&#39;);
	}

Simple function and it works.  But if I go into my Chrome settings and choose the option &quot;Don&#39;t Save Data&quot; (I don&#39;t remember exactly what it&#39;s called), when I try to run this function I get nothing but `Uncaught Error: SecurityError: DOM Exception 18`.  So is there a way to check if the person has it turned off completely?

UPDATE:  This is the second function I tried and I still get no response (alert).

    try {
	  localStorage.setItem(&#39;name&#39;, &#39;Hello World!&#39;);
    } catch (e) {
	  if (e == QUOTA_EXCEEDED_ERR) {
	   alert(&#39;Quota exceeded!&#39;);
	  }
    }

Check if localStorage is available

On my previous websites, I used to use a cookie to display a pre-home page only on the first visit. That worked great ([see for example here](http://newyork.arte.tv/)), but using cookies is not so trendy today, so I want to avoid it as much as possible.

Now, my new website projects almost always have pre-home launched via javascript (showing a modalbox), so I don&#39;t need to do any action on the server side. I&#39;m considering to use HTML5 localStorage instead of cookies, with a fallback on cookies if the browser does not have localStorage. Is this a good idea? What is the impact in terms of usability, privacy protection and website performance?

Using localStorage will improve usability for users that have disabled cookies. But I know that some HTML5 features are only opt-in (like geolocalisation) in some browser. Is there any restriction like that for localStorage on any browser ? Is there any case where I will get a JS error if localStorage is available but deactivated for my site ?

Are there any drawbacks to using localStorage instead of Cookies?

I&#39;m required to develop a web application that will function offline for long periods. In order for this to be viable I cannot avoid saving sensitive data (personal data but not the kind of data you would only store hashed) in local storage. 

I accept that this is not recommended practice, but given little choice I&#39;m doing the following to secure the data:

 - encyrypting everything going into local storage using the stanford javascript crypto library and AES-256
 - the user password is the encryption key and is not stored on the device
 - serving all content (when online) from a single trusted server over ssl
 - validating all data going to and from local storage on the server using owasp antisamy project
 - in the network section of the appcache, not using *, and instead listing only the URIs required for connection with the trusted server
 - in general trying to apply the guidelines suggested in the OWASP XSS cheat sheet

I appreciate that the devil is often in the detail, and know there is a lot of scepticism about local storage and javascript-based security in general. Can anyone comment on whether there are:

 - fundamental flaws in the above approach?
 - any possible solutions for such flaws?
 - any better way to secure local storage when an html 5 application must function offline for long periods?

Thanks for any help.



Can local storage ever be considered secure?

I want to show all of the keys and storage written before. 
My code is below. I created a function (allStorage) but it doesn&#39;t work. 
How can I do this? 


        function storeUserScribble(id) {
            var scribble = document.getElementById(&#39;scribble&#39;).innerHTML;
            localStorage.setItem(&#39;userScribble&#39;,scribble);
        }

        function getUserScribble() {
            if ( localStorage.getItem(&#39;userScribble&#39;)) {
                var scribble = localStorage.getItem(&#39;userScribble&#39;);
            }
            else {
                var scribble = &#39;You can scribble directly on this sticky... and I will also remember your message the next time you visit my blog!&#39;;
            }
            document.getElementById(&#39;scribble&#39;).innerHTML = scribble;
        }

        function clearLocal() {
            localStorage.clear();
            return false;
        }

        function allStorage() {
            var archive = [];
            for (var i = 0; i&lt;localStorage.length; i++) {
                archive[i] = localStorage.getItem(localStorage.key(i));
            }
        }



How to retrieve all localStorage items without knowing the keys in advance?

What are the technical pros and cons of `localStorage`, `sessionStorage`, session and `cookies`, and when would I use one over the other?

What is the difference between localStorage, sessionStorage, session and cookies?

I have some values in my site which I want to clear when the browser is closed. I chose `sessionStorage` to store those values. When tab is closed they are indeed cleared, and kept if the user presses f5; But if the user opens some link in a different tab these values are unavailable.

How I can share `sessionStorage` values between all browser tabs with my application?

The use case: put a value in some storage, keep that value accessible in all browser tabs and clear it if all tabs are closed.

    if (!sessionStorage.getItem(key)) {
        sessionStorage.setItem(key, defaultValue)
    }

Content Type	Original Author	Original Content on Stackoverflow
Question	Brian M. Hunt	View Question on Stackoverflow
Solution 1 - Javascript	Robert Harvey	View Answer on Stackoverflow
Solution 2 - Javascript	Taylor Henderson	View Answer on Stackoverflow

How large is HTML5 session storage?

Javascript Problem Overview

Javascript Solutions

Solution 1 - Javascript

Solution 2 - Javascript

How to clear Tkinter Canvas?

How can I build an enum with Dart?

Attributions