Default values

[jni-]

jQuery plugins often implement a way to provide defaults for a plugin, and i think that would be a good addition too.

For example, I always want to do the same when a JSON parsing error happens, and i don't want to write the function all the time.

Is there already a way to do this?

[blueimp]

I'm not sure if this is what you want, but there is the onError callBack option which gets called on XHR upload and JSON parsing errors (the latter only with the advanced User Interface plugin).

[jni-]

Yes and no. I know about this callback option, and i want to use it.

But lets say i use this plugin on alot of pages, i would like if i can define in one place something like

$.fileUploadUI.defaults = {}

Just like you can do with blockUI : http://jquery.malsup.com/block/#options

This way, i can define some callbacks and some options for all the forms on my site in the main.js. Most of my forms are loaded through AJAX calls with JS among it. If i define my function in each, even if that's just 0.5Kb more per AJAX call, it will eventually show. Plus it's not possible for browsers to cache it that way.

If someone else is worried about this, the best solution i found was to define my callbacks in main.js or somewhere like that, and passing it by reference, so you basically only have the name of the function going through AJAX.

So briefly, some options need to vary according to the form, some don't, and it's those i'd like to define as default values

[blueimp]

OK, now I understand what you meant by defaults for the plugin, thanks for the explanation.
Although the plugin doesn't currently offer a way to globally override it's default options, you can still make use of a custom set of default functionality the following way:
Define an object with your defaults:
var fileUploadDefaults = {
uploadTable: $('.upload_files'),
downloadTable: $('.download_files'),
buildUploadRow: function (files, index) {/* ... /},
buildDownloadRow: function (file) {/ ... */}
};
Then call the fileUpload plugin the following way, overriding some of the defaults with form-specific behavior:
$('.upload').fileUploadUI($.extend({}, fileUploadDefaults, {
downloadTable: $('.custom_download_files')
}));
See also the documentation on jquery.extend for an explanation of its usage.