Drupal 9 version

Problem/Motivation

I needed this to work for a Drupal 9 site - parse each line of a file based on a regex, and create nodes from lines that matched the regex, ignoring all other lines.

Proposed resolution

So I wrote the module. Any interest in folding it into this project?

Remaining tasks

A peer review would be nice. Also didn't write any tests, but...

User interface changes

Based on the CSV parser code, so UI is very much like that. However, there's a text area for the regex, with a fulsome description of how to construct a suitable regex (uses named patterns), and I exposed the limit iterator value. Also, the sub-pattern names in the regex appear as "RegEx Pattern Field: sub_pattern_name" in the mapping.

API changes

Feeds for Drupal 9, so completely different API.

Data model changes

Feeds for Drupal 9, so uses that data model.