{@user} taxonomy relationship magic tags output only first ID or pass false

[pd-cm]

Description

Magic tags for {@user.field} multi-select relationship taxonomy fields have inconsistent output and passed values to helper functions.

If multiple terms are assigned to the field:

• In a query for a CPT, {@user.field} outputs only the first term, and it's the Term ID.
• In a query for a CPT, {@user.field,helper_function} passes false to the helper.
• In a query over users, {@field} passes a formatted string of Term Names with "and".
• In a query over users, {@field,helper_function} passes an array of term arrays.

This was found to be an issue with taxonomy relationship fields associated with users.
It's not yet known whether the issue also applies to relationship fields from or to other object types or single-select fields.

Not included in the example, but also problematic, are {@user.field.term_id} and {@user.field.term_id,helper}

It's also notable that when adding fields to a user, a field key that is the same as a taxonomy key is allowed; this is not allowed on post types. While this did not seem to be the cause of the issue, as the tests check fields with two different names, it is confusing.

Originally reported in this thread where the field names and taxonomy names are in a mix of German and English, changing through the course of the conversation: https://wordpress.org/support/topic/compare-cpt-taxonomy-to-users-relationship-field/ . A PHP approach to expected behavior was provided on page 2: https://wordpress.org/support/topic/compare-cpt-taxonomy-to-users-relationship-field/page/2/#post-17019774

Version

2.9.19

Testing Instructions

1. Import the pods.json
2. Unzip and import this WXR: usertaxonomy.WordPress.2023-09-01.xml.zip
3. Assign multiple taxonomy terms to the current user using both fields on the user profile page.
4. Add this function:

function terms_from_taxonomy_relationship_magic_tag( $value ) {
	ob_start();
	var_dump( $value );
	return str_replace( PHP_EOL, '', ob_get_clean() );
}

6. View the page titled "test".

Screenshots / Screencast

Term 2 is term_id 4. Term 3 is term_id 5.

It's also notable that in the var_dump()s of the term arrays, term_id, term_taxonomy_id, parent, count, term_group, object_id, term_order, and pod_item_id are all of type string, while integer would most likely be appropriate.

Possible Workaround

Extensive unit tests.

Site Health Information

It's a LocalWP multisite on WP 6.3.1 with no other plugins active.

Pods Package

{
    "@meta": {
        "version": "2.9.19",
        "build": 1693599594
    },
    "settings": {
        "types_only": "0",
        "watch_changed_fields": "0",
        "metadata_integration": "1",
        "metadata_override_get": "0",
        "media_modal_fields": "0",
        "session_auto_start": "0",
        "wisdom_opt_out": "1"
    },
    "pods": [
        {
            "name": "page",
            "id": 19,
            "label": "Page",
            "description": "",
            "type": "post_type",
            "storage": "meta",
            "object": "page",
            "_migrated_28": "1",
            "groups": [
                {
                    "name": "more_fields",
                    "id": 20,
                    "label": "More Fields",
                    "description": "",
                    "weight": 0,
                    "fields": []
                }
            ]
        },
        {
            "name": "test_post",
            "id": 7,
            "label": "Test Posts",
            "description": "",
            "type": "post_type",
            "storage": "meta",
            "label_singular": "Test Post",
            "public": "1",
            "show_ui": "1",
            "rest_enable": "1",
            "supports_title": "1",
            "supports_editor": "1",
            "_migrated_28": "1",
            "built_in_taxonomies_test_taxonomy": "1",
            "groups": [
                {
                    "name": "more_fields",
                    "id": 8,
                    "label": "More Fields",
                    "description": "",
                    "weight": 0,
                    "fields": []
                }
            ]
        },
        {
            "name": "test_taxonomy",
            "id": 5,
            "label": "Test Taxonomy Terms",
            "description": "",
            "type": "taxonomy",
            "storage": "meta",
            "label_singular": "Test Taxonomy",
            "public": "1",
            "show_ui": "1",
            "hierarchical": "1",
            "rest_enable": "1",
            "_migrated_28": "1",
            "built_in_post_types_test_post": "1",
            "groups": [
                {
                    "name": "more_fields",
                    "id": 6,
                    "label": "More Fields",
                    "description": "",
                    "weight": 0,
                    "fields": []
                }
            ]
        },
        {
            "name": "user",
            "id": 9,
            "label": "User",
            "description": "",
            "type": "user",
            "storage": "meta",
            "object": "user",
            "_migrated_28": "1",
            "required": "0",
            "required_help_boolean": "0",
            "groups": [
                {
                    "name": "more_fields",
                    "id": 10,
                    "label": "More Fields",
                    "description": "",
                    "weight": 0,
                    "fields": [
                        {
                            "name": "test_taxonomy",
                            "id": 11,
                            "label": "Test Taxonomy",
                            "description": "",
                            "weight": 0,
                            "type": "pick",
                            "pick_object": "taxonomy",
                            "pick_val": "test_taxonomy",
                            "sister_id": "-- Select One --",
                            "pick_table": "-- Select One --",
                            "required": "0",
                            "required_help_boolean": "0",
                            "pick_format_type": "multi",
                            "pick_format_single": "dropdown",
                            "pick_format_single_help": "0",
                            "pick_format_multi": "list",
                            "pick_format_multi_help": "0",
                            "pick_display_format_multi": "default",
                            "pick_display_format_separator": ", ",
                            "pick_allow_add_new": "1",
                            "pick_taggable": "0",
                            "pick_show_icon": "1",
                            "pick_show_edit_link": "1",
                            "pick_show_view_link": "1",
                            "pick_limit": "0",
                            "pick_user_role": "Administrator",
                            "pick_post_status": "publish",
                            "pick_post_author": "0",
                            "repeatable": "0",
                            "repeatable_format": "default",
                            "roles_allowed": "administrator",
                            "rest_pick_response": "array",
                            "rest_pick_depth": "1"
                        },
                        {
                            "name": "rel_test_taxonomy",
                            "id": 12,
                            "label": "Rel Test Taxonomy",
                            "description": "",
                            "weight": 1,
                            "type": "pick",
                            "pick_object": "taxonomy",
                            "sister_id": "-- Select One --",
                            "pick_table": "-- Select One --",
                            "required": "0",
                            "required_help_boolean": "0",
                            "pick_format_type": "multi",
                            "pick_format_single": "dropdown",
                            "pick_format_single_help": "0",
                            "pick_format_multi": "list",
                            "pick_format_multi_help": "0",
                            "pick_display_format_multi": "default",
                            "pick_display_format_separator": ", ",
                            "pick_allow_add_new": "1",
                            "pick_taggable": "0",
                            "pick_show_icon": "1",
                            "pick_show_edit_link": "1",
                            "pick_show_view_link": "1",
                            "pick_limit": "0",
                            "pick_user_role": "Administrator",
                            "pick_post_status": "publish",
                            "pick_post_author": "0",
                            "repeatable": "0",
                            "repeatable_format": "default",
                            "roles_allowed": "administrator",
                            "rest_pick_response": "array",
                            "rest_pick_depth": "1",
                            "pick_val": "test_taxonomy"
                        }
                    ]
                }
            ]
        }
    ]
}

[JoryHogeveen]

Hi @pd-cm
Could you please test my patch for this issue? #7153

It's also notable that when adding fields to a user, a field key that is the same as a taxonomy key is allowed; this is not allowed on post types. While this did not seem to be the cause of the issue, as the tests check fields with two different names, it is confusing.

Users do not have taxonomies by default in WordPress, therefore these are not reserved keys for users.
When using relationship fields these taxonomies are not stored as term relationships but as metadata.