Ajax.BeginForm AjaxOptions custom arguments for OnComplete, OnSuccess, OnFailure and OnBegin

Some interesting behavior I noticed recently about the Microsoft MVC 3 jQuery library jquery.unobtrusive-ajax.js is the ability to pass you own arguments into the handler.

Normally you have probably used it like this:

@using (Ajax.BeginForm(new AjaxOptions{OnComplete = "DefaultEditOnComplete"}))
{
    //Person data and submit button
}

This works pretty well but it’s not very clear if/how you could pass additional arguments into the OnComplete (possibly to get some code reuse anyone?). If you take a look at the jquery.unobtrusive-ajax.js source however it becomes apparent that you can actually pass any (*see notes at end of post) arguments you want into your OnComplete.

Here is an example of just that:

@using (Ajax.BeginForm(new AjaxOptions{OnComplete = "DefaultEditOnComplete(xhr, status, 'Person')"}))
{
    //Person data and submit button
}

Here is what the OnComplete JavaScript function looks like:

function DefaultEditOnComplete(xhr, status, entityName) {

    //xhr - the ajax response
    //status - the response text, ex. "success"
    //entityName - your custom argument, in this example 'Person'

    alert('DefaultEditOnComplete fired for ' + entityName);
}

This should work fine for all the types of events specified in AjaxOptions, but different argument names are available for the different events:

• OnBegin – xhr
• OnComplete – xhr, status
• OnSuccess – data, status, xhr
• OnFailure – xhr, status, error

*I have noticed one problem with passing arguments, do not include a ‘.’ in any passed arguments. The function ‘getFunction’ does a split on ‘.’ on passed arguments presumably for some JavaScript namespacing/method purposes?