Content management for existing PHP project

Question

In existing project which is developed as complete custom solution we face need for content management system (for us as well as client). Our current generic needs are (in WordPress terminology):

• Create custom post types and taxonomies (translable & versioned).
• Access given content by progammable API (e.g. get all item of certain post types)
• Administration for given post type (datagrid + forms)

Considered following options:

1. Use "standard" CMS (Drupal, Wordpress) - seems impossible as they seem too standalone to just use part of them which would mainly require complete rewrite of our current codebase (which is impossible).
2. Write such functionality to fit the project - no that much abstract, but no-reusable.
3. Library providing described functionality, just install and configure the post types, taxonomies... - would be perfect, but haven't found so far. (Symfony CMF seems that it could do this, hard to say from documentation).

Questions:

1. Is there any CMS with described functionality that would be possible to integrate into existing project?
2. Is there any library providing described functionality?

Note: previously asked on https://stackoverflow.com/questions/42230616/content-management-for-existing-php-project as I considered it to be a more programming related question.

Answer 1

From what you wrote I'd say that you should have another look at Drupal.

• You can easily define your post content types, with custom field names, field types and relational fields. You can translate each post and can define its URL schema. The taxonomy system rocks, you can have parent-child relationships, synonyms, parallel taxonomies, etc.
• Drupal 8 core is well structured and could theoretically be included as a dependency in your PHP project, where only parts of the Drupal API can be used to have programmatic access to the content objects (querying, filtering, creating, etc). Alternatively, you can use the REST API for access.
• Administration for post types can be configured.

I'd advise against using a "library" for this, because that library will be lacking all administration functionality (data grid and forms, access restrictions, authentication) and you will be ending up writing your own CMS.