Working on the principle that any content is better than no content here's a little tip some of you (probably not the experts though) might find useful.

I was working on an Ajax-based document rating system this week and seeing some unexpected results (that is, nothing was happening). After staring blankly at the LotusScript code for a while I looked elsewhere and it turned out that the calls to the rating agent were being cached by IE.

To prevent the Ajax call caching I added an extra parameter the function which creates the GET URL, like so:

$.get( "RateArticle?OpenAgent",
        { 
                article: id, 
                ajax: true, 
                rate: rate, 
                _: new Date().getTime()
        },
        function(data){
                alert(data)
        }
)

Calls to the JavaScript function which contains the above Ajax code will result in URLs like so:

Obviously each one is unique and never repeated, so caching is not a problem.

In this case the problem is only ever during testing as, in practice, a document rating URL is only ever called once per article and so it's the id= parameter that makes each one unique - per user. However, it's a handy trick to use in any Ajax call and hence I thought I'd share it with you all.

Whenever you find yourself building a list of parameters to pass in a URL you don't want caching, tag "new Date().getTime()" to the end of it.

Alternatively, assuming your LotusScript Agent is returning all the content you could prevent caching from there. Like so:

Print "content-type: text/plain"
Print "cache-control: no-cache"
Print |{ rate: 4, message: "Thank you for rating this article."}|

This is all probably old hat to lots of you, but I'm always mindful that there are a wide range of skill-sets among my readers.