W3C home > Mailing lists > Public > public-webapps@w3.org > July to September 2014


From: <nmork_consultant@cusa.canon.com>
Date: Tue, 29 Jul 2014 14:41:27 -0400
To: public-webapps@w3.org
Message-ID: <OFAC74E2A6.C0DAD4EC-ON85257D24.0064C76D-88257D24.0066ACBF@cusa.canon.com>
While debugging an intranet application using xmlHttpRequest recently, I 
got a message on the Firefox browser console: "Synchronous XMLHttpRequest 
on the main thread is deprecated because of its detrimental effects to the 
end user's experience."

This worries me, since many useful web browser features which are 
"deprecated" eventually disappear (e.g. CSS width specification in the 
<col> tag.)  I have an application which makes many http requests to make 
multiple large updates to database work tables, finally running a single 
SQL xmlHttpRequest to copy all work table data to the main data tables 
after all updates are successful.

1. The volume and size of the data is too large to be sent by a single 
2. Each subsequent request cannot be submitted until the prior request is 
completed SUCCESSFULLY or the database will be corrupted
3. The final SQL acts as the "commit" for the whole shebang and has its 

In this case, synchronous xmlHttpRequests are not only NOT deprecated, 
they are ABSOLUTELY ESSENTIAL to provide reliable database updating for 
the end user, and reliability is what the end user most desires, in 
addition to IMMEDIATE FEEDBACK whether the update succeeded or not.

Please do not deprecate synchronous xmlHttpRequests.  They are needed in 
general and specifically needed for complex web applications.

Also, unrelated, please bring back CSS width to the <col> tag.  On very 
large data tables, this can reduce page downloads by megabytes, no matter 
how small you make your column class names.
Received on Thursday, 31 July 2014 07:26:43 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 18:14:26 UTC