Deprecate zope.formlib

[gforcada]

A quick search reveals some usage as well: https://github.com/plone/plone.app.vocabularies/search?utf8=%E2%9C%93&q=formlib&type=Code

Is there any porting guide out of it? Should that be replaced by z3c.form?

[jensens]

What we have

From formlib theres only the ISourceQueryView interface used:

• Interface https://github.com/zopefoundation/zope.formlib/blob/master/src/zope/formlib/interfaces.py#L334
• Usage https://github.com/plone/plone.app.vocabularies/search?utf8=%E2%9C%93&q=ISourceQueryView&type=Code

I seems this is an old definition for what then was expressed by zope.browser.interfaces.ITerms https://github.com/zopefoundation/zope.browser/blob/master/src/zope/browser/interfaces.py#L88

But even this is kind of deprecated, because the "All source implementations will be deprecated"

plone.app.vocabularies/plone/app/vocabularies/configure.zcml

Line 162 in ad75d57

<!-- All source implementations will be deprecated -->

Proposed Solution:

• Really deprecate all source implemenations (let them emit a DeprecationWarning), see http://docs.plone.org/develop/styleguide/deprecation.html
• conditional import from zope.formlib, if not available provide stub Interface
• conditional registration in zcml (only if zope.formlib is available)
• mark code for removal in Plone 6