Helper methods provided by Blacklight should be easily overriden by local implementations

[MrDys]

CODEBASE-364: From http://groups.google.com/group/rubyonrails-core/browse_thread/thread/3da0012435e7c72a

I want to let the local application selective over-ride helper methods from AdvancedHelper in the engine (and ideally be able to call 'super'). That's a pretty reasonable thing to want to allow, right, a perfectly reasonable (and I'd think common) design? Problem is I can't get it to work. Let's say there's a method

do_something in the engine's app/helpers/advanced_helper.rb.

• If the local app provides an app/helpers/advanced_helper.rb, then it completely replaces the one from the engine, the one from the engine isn't loaded at all. (So it has none of it's methods, even though we just wanted to over-ride one of em). Okay, this isn't actually TOO unexpected.
  • So I provide a helper called, say local_advanced_helper.rb(LocalAdvancedHelper) in my local app/helpers. It DOES load. If it implements a #new_method_name, that helper is of course available in views (including the engine's views, as it happens). However, if it tries to over-ride the engine's

    do_something ... the local do_something is never called.

[MrDys]

Original reporter: jrochkind

[MrDys]

cbeer: Fixed in https://github.com/projectblacklight/blacklight/commit/2f205df335f2cc816aa2b03d48b18055bb7b81c7

[MrDys]

cbeer: This is an older issue that I thought was addressed earlier -- at least my local applications were working ok, but apparently that may have been a fluke.

We intend to address this as follows:

• The implementations from the Blacklight helpers will be moved from the app/helpers/helper.rb files and into "behavior" modules. These behavior files will live in app/helpers/blacklight/helper_behavior.rb (which won't be automatically loaded by Rails)
• Alternative implementations of the existing helpers will be provided that include the newly created behavior files.
• Local applications who want to override Blacklight-provided methods must create a new file in the local app/helpers with the same name as the helper they want to override. Using the same approach as the Blacklight-provided helpers, they can load the Behavior files, e.g.:

app/helpers/catalog_helper.rb:

module CatalogHelper include Blacklight::CatalogHelperBehavior # it'll get this from the plugin, great

and now we can individually over-ride whatever methods

from Blacklight::CatalogHelperBehavior we want, and not the others.

end