If you turn on extended-data in configuration profile then you may start missing out on some of the data that should be passed to your application. The reason for this is that the default method is a GET request. All the information that is passed with extended-data can often exceed the maximum allowed length of CGI parameters, which results in cutting off some of the data from the end of the request. There are a couple of ways to fix this. The most permanent way is to set the method parameter in the httapi.conf.xml file as shown here:

<param name="method" value="POST"/> 

However, there is a way to set the method per-request if you decide that you only want to set the method to POST on the requests that are causing issues. You can set the method in the URL string as shown here:

<action application="httapi"  
  data="{url=http://localhost/httapi/index.php,method=POST}"/>