Skip to main content

Caching in Safari on IOS 6 for Ajax calls

When using caching for Ajax calls, the standard rule is to cache GET requests and not to cache POST requests. However Apple seems to have broken this rule in IOS 6 release. Safari seems to be aggresively caching in order to improve performance on iPad.

We noted this problem when one of our applications started failing as it wasn't calling a webservice using Ajax. We couldn't replicate the problem on a PC. So after enabling logging for the webservice, we noticed that Safari wasn't calling the webservice after first call and caching the content. The logic Safari uses that if the parameters and the value of parameters is  same, then it will use cached reponse.

We tried disabling the caching by setting response headers to prevent any form of caching. Safari ignores all caching headers (Thank you apple for deviating from standards...). The only workable solution is to set of the parameters which will have a different value for every request. We have used a timestamp. This forces Safari to fetch updated content on every request.

Here is an good article which explains the problem

http://arstechnica.com/apple/2012/09/developers-claim-safari-in-ios-6-breaks-web-apps-with-aggressive-caching/

Update: 2013-01-29 : It is expected that IOS 6.1 update will contain the fix for this. IOS 6.1 is out now.
Labels:

Comments

Post a Comment

Popular posts from this blog

Searching Unicode characters in Oracle table

Oracle implementation of Regular expression has no support for using hexadecimal code to search for Unicode characters. The only way to search for Unicode character is it use the character itself. Normally with Regular expression, you can use \x or \u followed by hexadecimal code to search for any character. E.g. \x20 will match space. But REGEXP_LIKE in Oracle does not support \x. You need to use unistr function to convert the code to equivalent character and then use it with REGEXP_LIKE. E.g. REGEXP_LIKE(source,'[' ||unistr('\0020')|| ']');
Post a Comment
Read more

C# Performance Improvement - The Power of StringBuilder

 Often when we are wring code we don't think about performance and go with the default options available to achieve a task. String concatenation is one such scenario. If you are doing simple and few string catenations, then you can use the following result = string1 + string2; string1+= string2; result = String.Concat(string1,string2); String.Format and string interpolation are few other options.  However when you are performing large and repetitive  operation, string catenation can be expensive. Here is an example to prove the point.  As you can see it took 41 seconds to perform 100k string catenation. Now lets replace this with StringBuilder and see.  8 ms!!!!!! That is a massive performance difference. Hope you get the point. More info on StringBuilder can be found here https://learn.microsoft.com/en-us/dotnet/api/system.text.stringbuilder?view=net-7.0
Post a Comment
Read more

How to get started with .Net Core and Lambda functions?

 Recently I started experimenting with .Net Core and AWS Lambda functions, I thought I will share the steps I took to get started Tools to install .Net Core 3.1 -  https://dotnet.microsoft.com/download/dotnet-core/3.1 AWS CLI -  https://aws.amazon.com/cli/   AWS Account - 12 months Free Tier -  https://aws.amazon.com/free Terminal - on iOS I use iTerm2 -  https://www.iterm2.com   Once you installed the above tools, head to AWS console and login with your root account to create an account which will be used by AWS CLI. Please see steps here   Now you can configure AWS CLI as detailed here . Verify that you able to connect to AWS service using CLI. To make life little easy with dotnet core and Lambda functions, you need to install AWS Extensions nuget pack for .Net CLI dotnet tool install -g Amazon.Lambda.Tools You can also install templates to get started quickly  dotnet new -i Amazon.Lambda.Templates That's it. Now the fun part!!!  Creat...
Post a Comment
Read more