Compatibility with Display Suite

Problem/Motivation

An error occurs when this module is used in combination with Display Suite's core fields (like node Post Date). It's down to the fact that these DS fields are not fully conformant to Field API. For a detailed analysis see the related issues in Display Suite.

Proposed resolution

1. #1875634: Remove Field Formatter Class settings in uninstall →
   Cleaning up this module's settings on uninstall would at least allow recovery from the situation described in Comment #5.
2. The rest is best fixed in Display Suite project. Track the related issues for Display Suite.
   Potentially affects all modules using Field Formatter Settings API in combination with Display Suite.
3. If no satisfactory resolution in Display Suite, consider adding some workaround code for DS core fields.
   For a possible approach, see the workaround (hacky) in Field Formatter Conditions

Related Issues

#1875634: Remove Field Formatter Class settings in uninstall →
#1875750: Allow DS core fields to have alterable settings, include them in field_info_instance_settings() →
#1900014: Field formatter settings summary alter implementations choke on DS Pseudo fields →

Original report by marcorai

I install your module and it works for my objectives, but i had these error messages:

Notice: Undefined index: title in field_formatter_class_formatter_info() (linea 68 di /sites/all/modules/field_formatter_class/field_formatter_class.module).
Notice: Undefined index: post_date in field_formatter_class_formatter_info() (linea 68 di /sites/all/modules/field_formatter_class/field_formatter_class.module).

How can I fix it?