Mark IGenshiStreamFilter as legacy

[seanh]

and make sure this shows up in the plugin interfaces docs

also any other plugin interfaces that should be marked legacy or deprecated

[tobes]

it would be easy enough to poll all IGenshiStreamFilter extensions at startup and do a log.critical or similar.

Do we also want to do a log.warn when genshi templates are used (maybe not till 2.1 though)

[vitorbaptista]

I started doing this in https://github.com/vitorbaptista/ckan/commit/d0115492b36e5894395398d40273fbcd589b9049. I've added a warning every time a IGenshiStreamFilter is used, adding the extension's name.

I don't like the deprecated message in the docs so far. I think it's missing what should be used instead of IGenshiStreamFilter... what do you think?

[seanh]

I think the jinja equivalent of igenshistreamfilter is overriding blocks in templates, or if the template doesn't have any blocks you have to override the whole template file. @tobes @johnmartin

[tobes]

@vitorbaptista

I'd still prefer that we did this a plugin registration time to say this plugin uses the IGenshiStreamFilter which is deprecated as

a) we will not hit the place you added the warning for jinja2 templates so there will be no warning
b) That way we only warn once and it will be at application startup.

@seanh

yeah the jinja2 way is {% ckan_extends %} or via ITemplateHelpers

[vitorbaptista]

Solved by #365