Add an optional group to the status key to allow separation of prefetch status from normal page status.

[DavidCPhillips]

Closes #116

[rviscomi]

WDYT of implementing this with var_args? The "arguments" object is array-like, but not sure if spf.array handles it well enough.

I like not having to wrap this method's input in an array each and every time.

[nicksay]

why not simply

return type + '-' + label + (opt_group ? '-' + opt_group : '');

[rviscomi]

+1 that makes more sense, so that the order of the input is somewhat enforceable. Also O(1) instead of O(n) 😉

[DavidCPhillips]

@nicksay I felt that the function had an awkward name/use case combination. The name implied some generic prefixing capability, but really only built keys from one specific combination. In fact, many of the users refer to the output as 'key'.

So instead I figured it would make more sense as a generic key maker for resources. Which would work equally well for any set of labels that were being sent to it. I wouldn't necessarily be to opposed to

spf.net.resource.key = function(type, label, opt_group)

But, I would put money on a new variable being needed soon enough, and we'd revisit it again.

@rviscomi Added in var args.

[nicksay]

Perhaps, but given the broad usage, I'd prefer to avoid the repeated array creation and iteration. Also, the tighter type-annotation of the arguments version will allow better optimization and error checking. (We should probably actually change the second arg to be {string} to allow possible string joining during compilation.)

No problems with renaming the function.

[DavidCPhillips]

Alright fair enough. I went to back to specified parameters, and left it as spf.net.resource.key.

[rviscomi]

LGTR

[nicksay]

LGTM