You've created custom fields for user registration in Joomla 5, assigned them to the registration form context, but they render as
disabled (greyed out). Users can see them but can't fill them in. The fields work fine in the admin user editor.
Symptoms
- Custom fields appear on the registration form
- They are visually greyed out / disabled
- Inspecting the HTML shows disabled="true" on the input elements
- Even if you remove the disabled attribute with JavaScript, the values are stripped server-side
- The same fields work perfectly when editing a user in the admin backend
Root Cause
Joomla's
FieldsPlugin.php (around line 305) checks
FieldsHelper::canEditFieldValue($field) before rendering each field. If the current user doesn't have
core.edit.value permission on that field's asset, the field gets
disabled="true".
On top of that, the
onContentNormaliseRequestData handler strips values from disabled fields server-side. So even a JavaScript hack to remove the disabled attribute won't work -- the values are rejected on submit.
The permission check walks up the asset tree:
1. Check the specific field asset:
com_users.field.{ID}
2. If no asset record exists, check the parent component:
com_users
3. If nothing found, check root asset
For guest users (registering), Joomla checks the
Public group (group ID 1). By default, Public has no
core.edit.value permission anywhere -- so every custom field is disabled.
The Fix (Safe Way)
Create individual asset records for each field, granting
core.edit.value to the Public group on only those specific fields:
Step 1: Find the parent asset ID for com_users
Code:
SELECT id, lft, rgt FROM j5_assets WHERE name = 'com_users';
Step 2: Insert asset records for each field
For each custom field (e.g., field ID 5):
Code:
-- Get insertion point
SET @parent_rgt = (SELECT rgt FROM j5_assets WHERE name = 'com_users');
-- Make room in the nested set tree
UPDATE j5_assets SET rgt = rgt + 2 WHERE rgt >= @parent_rgt ORDER BY rgt DESC;
UPDATE j5_assets SET lft = lft + 2 WHERE lft >= @parent_rgt ORDER BY lft DESC;
-- Insert field asset
INSERT INTO j5_assets (parent_id, lft, rgt, level, name, title, rules)
VALUES (
(SELECT id FROM j5_assets WHERE name = 'com_users'),
@parent_rgt,
@parent_rgt + 1,
(SELECT level + 1 FROM j5_assets WHERE name = 'com_users'),
'com_users.field.5',
'Field: Your Field Name',
'{"core.edit.value":{"1":1}}'
);
The key is
{"core.edit.value":{"1":1}} -- this grants the permission to group ID 1 (Public) on this specific field only.
WARNING: Do NOT grant
core.edit.value to Public on the entire
com_users component. That would apply to ALL current AND future fields, which is a security risk.
[hr]
This is one of 65+ gotchas documented in
The AI Joomla Blueprint --
theaidirector.win
