In the Web2.0 Application (normally using the Ajax-typed technique), we normally don't need to download all data to One page.
We only need to download the necessary data (say "begin data") & when we need other data (say "other related data") then we just need to call them. However, there is a problem. That is, at the time we downloaded the "begin data" we got the latest up-to-date data. We then use that data for many hours, but at that time the "begin data" in the database was changed by other user. Ok, now we has the old "begin data" on the page of our Web2.0 app & we also have the new (latest) "begin data" in the Database. Then, we get the "other related data". At this time, the user didn't know that the "begin data" got updated, so they continue to work on the "other related data" with the assumption that the "other related data" is in the context of OLD "begin data", but in fact the "other related data" was already in the context of NEW "begin data". Let see 1 simple example. We got 2 tables BeginData (ID1 is primary key) & OtherRelatedData (ID2 is primary key) all related to each other. At the beginning we have these 2 tables: BeginData ID1 - ID2 - Text 1 - 3 - begin data text 1 OtherRelatedData ID2 - Text 3 - other related data text 1 Now user "A" downloaded "begin data" so he working on this record "1 - 3 - begin data text 1" for many hours. At the same time, a user "B" modified BeginData & because they are related so "other related data" also got modified: User "B" modified data: BeginData ID1 - ID2 - Text 1 - 3 - begin data text 2 OtherRelatedData ID2 - Text 3 - other related data text 2 Now user "A" did not download the latest "begin data" & he is using "1 - 3 - begin data text 1" then he get the "other related data" then the system will provide him "3 - other related data text 2", so he thought the "3 - other related data text 2" is in the context of "1 - 3 - begin data text 1" but actually it is not. This is very serious. What if we have so many related data like this then how can we manage them? Do we need to check the consistency of "begin data" & "other related data" on 1 page whenever we get the "other related data"? -- You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/google-web-toolkit. For more options, visit https://groups.google.com/d/optout.
