When auto-populating a date picker, use the date picker's format

[kirk-circle]

Overview

This patch ensures that when a CF date picker field is auto-populated, it uses the format specified by the date picker.

Before

When a processor auto-populated a form with the logged in user's data, any date values (e.g. date of birth) being put into date pickers were being left in the format in which they were returned from the CiviCRM API, e.g. 'yyyy-mm-dd'. If the date picker specified a different format, then the date picker misread and scrambled the date value.

After

When a processor is auto-populates a form with the logged in user's data, any date values being put into date pickers are converted to the format specified by the date picker.

Technical Details

CF date pickers use a different formatting specification to the one used by PHP date functions. A new function - translate_date_picker_format - translates from the former to the latter.

This patch only reformats dates that have been left in ISO 8601 format (the format in which dates are returned by the CiviCRM API). This is to avoid any problems that might be caused if the value has been altered, e.g. by the cfc_filter_mapped_field_to_prerender filter.

Comments

This solution is not perfect, but it is better than before. Problems can still arise if the date picker's format includes literal text other than dashes or slashes, but in most cases it won't.

[kirk-circle]

See #108 for a description of how to reproduce the bug addressed by this PR.

[mecachisenros]

@kirk-circle thank you for this, I'll review it today and get back to you.

[mecachisenros]

@kirk-circle this looks very good, thank you! I suggested some amendments before merging.