Defining Your First Custom Field

A focused walkthrough of a single field: change its type, validate its input, then lock it down for editing.

1. Change the type

Start with ->change_type($field, $type, $length = '', $extra = []) to pick how the field renders in the form:

$xcrud->change_type('email', 'text');

See Field Types Overview for the full list of available types.

2. Validate its value

->validation_pattern($field, $pattern) requires a field's (non-empty) value to match a regex in the Add/Edit form, enforced both client- and server-side. $pattern is either one of the named shortcuts below, or a literal regex body with no delimiters:

$xcrud->validation_pattern('email', 'email');

Shortcut	Matches
`email`	A simple `user@host` shape
`alpha`	Letters only
`alpha_numeric`	Letters and digits
`alpha_dash`	Letters, digits, underscore, hyphen
`numeric`	An integer or decimal number, optionally negative
`natural`	Digits only (a non-negative integer)
`url`	An `http://` or `https://` URL

For anything else, pass a literal regex body (no slashes, no flags):

$xcrud->validation_pattern('sku', '^[A-Z]{2}-\d{4}$');

An empty field passes a pattern check on its own - pair it with ->validation_required() to also forbid leaving it blank. See Field Validation for the full required/pattern write-up.

3. Show it, but block editing

->readonly($field) and ->disabled($field) both display a field in the form while preventing the visitor from changing it - the difference is purely cosmetic (a readonly-styled input vs. a grayed-out disabled control). Neither is a server-side security control: they only change what the browser lets a visitor click, not what the API accepts.

$xcrud->readonly('accountNumber');

A visitor who calls the REST API directly, bypassing the form entirely, is not stopped by readonly()/disabled() at all. The real security boundary is whitelisting which columns are editable in the first place - see Security: Blacklisting Tables & Columns.

Putting it together

$xcrud = Xcrud::get_instance();
$xcrud->table('customers');
$xcrud->route('customers');

$xcrud->change_type('email', 'text');
$xcrud->validation_pattern('email', 'email');
$xcrud->readonly('accountNumber');

$xcrud->render();