Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>One answer: Among other things, <strong>unload events cause the back/forward cache to be invalidated</strong>.</p> <p>Some browsers store the current state of the entire web page in the so-called "bfcache" or "page cache". This allows them to re-render the page very quickly when navigating via the back and forward buttons, and preserves the state of the DOM and all JavaScript variables. However, when a page contains onunload events, those events could potentially put the page into a non-functional state, and so the page is not stored in the bfcache and must be reloaded (but may be loaded from the standard cache) and re-rendered from scratch, including running all onload handlers. When returning to a page via the bfcache, the DOM is kept in its previous state, without needing to fire onload handlers (because the page is already loaded).</p> <p>Note that the behavior of the bfcache is different from the standard browser cache with regards to Cache-Control and other HTTP headers. In many cases, browsers will cache a page in the bfcache even if it would not otherwise store it in the standard cache.</p> <p><del>jQuery automatically attaches an unload event to the window, so unfortunately using jQuery will disqualify your page from being stored in the bfcache for DOM preservation and quick back/forward</del>. [Update: this has been fixed in jQuery 1.4 so that it only applies to IE]</p> <ul> <li><a href="https://developer.mozilla.org/En/Using_Firefox_1.5_caching" rel="noreferrer">Information about the Firefox bfcache</a></li> <li><a href="http://webkit.org/blog/427/webkit-page-cache-i-the-basics/" rel="noreferrer">Information about the Safari Page Cache</a> and <a href="http://webkit.org/blog/516/webkit-page-cache-ii-the-unload-event/" rel="noreferrer">possible future changes to how unload events work</a></li> <li><a href="http://www.opera.com/support/kb/view/827/" rel="noreferrer">Opera uses fast history navigation</a></li> <li>Chrome doesn't have a page cache (<a href="http://code.google.com/p/chromium/issues/detail?id=2879" rel="noreferrer">[1]</a>, <a href="http://code.google.com/p/chromium/issues/detail?id=48657" rel="noreferrer">[2]</a>)</li> <li>Pages for playing with DOM manipulations and the bfcache: <ul> <li><a href="http://www.twmagic.com/misc/cache.html" rel="noreferrer">This page will be stored in the regular cache</a></li> <li><a href="http://www.twmagic.com/misc/cache-nocache.html" rel="noreferrer">This page will not, but will still be bfcached</a></li> </ul></li> </ul>
    singulars
    1. This table or related slice is empty.
    1. POAjax, back button and DOM updates
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USMiles
    1. USMiles
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POAjax, back button and DOM updates
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTAcceptedByOriginator
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COyou totally nailed it. both, reddit and stackoverflow are using jquery while basecamp and apple are using prototypejs. this pretty much explains everything.
      singulars
      1. PO
      1. USlubos hasko
    2. CO+1 interesting ( not cross browser though ) the question is far different than when it started...
      singulars
      1. PO
      1. USBigBlondeViking
    3. COit will be probably cross-browser because I can reproduce it on my Internet Explorer as well. I'm sure every webbrowser with javascript enabled had to deal with this problem anyway. but this is really a mess, when you think about that, back button should always get people to the page that they've seen last with all DOM updates, javascript state etc. developers shouldn't break this by doing something in unload event and if they do, webbrowsers shouldn't try to fix the problem by not using bfcache at all. whole unload event is one big joke. I'm sure 99% of time it's used to patch memory leaks.
      singulars
      1. PO
      1. USlubos hasko
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload