Resource Hints: improve filtering

[dimadin]

By looking at name and description of wp_resource_hints filter, one would assume that it filters all resource hints, while it is in foreach loop filtering only one relation type at the time. This means that unless you want to always pass an empty array, you need to arguments and then conditional.

I suggest that we change this before RC. There are a few ways to do, attached is with moving filter with wp_resource_hints name before loop and filtering all resource hints there, while making current filter name dynamic, based on relation type currently used,

[ocean90]

For 4.6 we should only improve the docs of the existing filter.

[peterwilsoncc]

Needs refresh following @ocean90's comment re 4.6.

There is a reluctance to add further dynamic filter names to WP core as it makes searching more difficult, passing parameters is preferred.

[ocean90]

@peterwilsoncc What do you think about 37458.3.diff​?

[peterwilsoncc]

In 38161:

Script Loader: Clarify documentation of wp_resource_hints hook.

Specify that the wp_resource_hints hook is firing for a single relation type.

Props: dimadin for initial patch.
See #37458.

[peterwilsoncc]

The documentation has been improved in [38161].

I'm going to close this off as wontfix for the reasons I mentioned earlier about dynamic filters.