jQuery Forum

I'm not opposed to making this change, and technically it should not affect anyone since the current behavior isn't something that anyone should be depending upon. Of course we often find out that there is a lot of undocumented behavior that people exploit, which is often reason enough to avoid making a change. It seems to me that items with a value of null or undefined should not appear in the serialization at all, is there a reason why you'd want them coerced to an empty string? In a JSON serialization for example, undefined entries don't appear. But this is why a seemingly simple request is harder to implement than you might think.

Can you create a ticket for this suggestion at bugs.jquery.com and reference this thread? That way we can get it tracked and make a decision on it.

I definitely not in favor of creating some flag that lets people select the old or new behavior. We did that with the ajaxSettings.traditional flag and I think it was a mistake. In that case the new behavior was the default, which is what I suspect you are recommending here. So some old code broke until users went in and changed their code to flip the traditional flag. Even if we do it the other way around it just complicates the code and documentation; it becomes more straightforward for the few people who need the exceptional behavior to do it themselves, rather than push the burden onto everyone.

In your example, you set foo equal to null, and you have a problem with null being passed as a url value. 

I don't see how this is a problem. foo is null, so it passes null. if it was undefined, it would pass undefined. if it was an empty string, it would pass an empty string. where is the issue?

Should jQuery.param() be automagically reassigning the values that you are passing into it?

If I wanted jQuery.param() to return an empty string for a value, i would pass that value as an empty string, not null or undefined.

Edit: In the end though i dont think a change like this would affect very many people. how many times do you use .param() on something other than form elements? i personally haven't come across this scenario before.

-- Kevin