How to avoid roundtrip to server on value select in dropdown box in ALV cel

Question

Dear Experts,
I have WD ALV table where user edits values in the cels using dropdown by key element.
Then after edit he saves whole table. When value is changed in dropdown box the roundtrip to server occurs and it takes noticable time for every cell. My dropdown lists are fixed and are the same for all rows. It is not pleasant user experience and is annoying for user.
Is there a way to disable this roundtrip for each value selection for each cell and transfer all the data for whole ALV table only when I save whole table (separate button "Save")?
Help very much appreciated.
Dmitry

Answer 1

A lot of enterprises, however, actively avoid systems which are locked down to a particular server for very legitimate reasons. If my data center dies in the middle of the night, I sure don't want to have to call your mobile phone so that you can get to a computer, log in to the office network, and get me a new key so that I can finish my emergency failover. If I've got dozens of applications, I absolutely don't want to do that with dozens of different vendors.
It sounds like your problem, though, isn't that users are installing your software on multiple computers it's that they are accessing functionality they haven't licensed. That is generally a much easier problem to solve and doesn't require you to lock anything down to a particular machine. You can create a table LICENSED_CONTENT, for example,
CREATE TABLE licensed_content (
  client_id    NUMBER,
  content_type VARCHAR2(30),
  key          RAW(128)
)In this case, KEY is, say, a hash (using the DBMS_CRYPTO or DBMS_OBFUSCATION_TOOLKIT packages if you'd like) of the client_id, content_type, and a bit of salt (i.e. a fixed string that only you know). When you sell a license to manage diamond content, you provide a script that inserts the appropriate row in the LICENSED_CONTENT table. When your application starts up, it reads the LICENSED_CONTENT table and verifies the hash before allowing users to access that type of content. This allows legitimate customers to move the software from one system to another but prevents them from accessing new functionality without a new license.
Justin