Fields are the core of an admin model. Each field describes a database column, its form input, its validation rules, its relations and how it is shown in the listing table.
The database follows the fields. Run php artisan admin:migrate after every change, see changing fields.

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Writing fields

Return the fields from the fields() method of the admin model. Each key is the name of a database column, the value is the field configuration combined with Laravel validation rules. The configuration is written as a string of parameters separated by |, or as an array.

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String notation

This notation is recommended for all fields.
app/Models/Product.php
Parsing rules:
  • A parameter without a value is a flag and becomes true, required is required => true.
  • Values are always strings, default:10 becomes '10'.
  • Only the first colon separates the key, so title:Opens at 10:30 or date_format:H:i keep the rest of the value.
  • A repeated parameter becomes an array of values, index:a|index:b is index => ['a', 'b'].
  • Empty parts are ignored (name:Name||required), placeholder: sets an empty string.
  • A value can not contain |. Use the array notation when you need it.
The form generated from a field definition:
Form generated from the field definition

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Array notation

Each field can also be an array. Values keep their PHP types, and a value without a key is a flag.
Use real booleans. 'required' => 'true' is a string, it is passed to Laravel validation but the column stays nullable.

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Method notation

Validation often differs between creating a record and editing it. The fields() method receives the edited record as $row, which is null in the create form. Combine the string notation with arrays when you need Laravel rule objects.

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Field keys

The field key is the database column name. Keys are slugged with _ as the separator, so they are also lowercased: Always use snake_case keys. The original camelCase key is not recognised in requests, in getField() or as $row->firstName.

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Field parameters

Every parameter which is not an admin parameter is passed to the Laravel validator as a rule, see validation rules. The admin parameters are documented on these pages: Fields can be arranged into groups and tabs, and fields of an existing model can be changed with mutateFields(), see groups and tabs.

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Custom field parameters

A parameter which only expands into other parameters is a rule alias (custom_rules, global_rules). A parameter with its own logic is a field mutation: one class which changes every field carrying the parameter, in all models. Use a mutation instead of repeating the same change in mutateFields() of several models, and for every parameter a package adds.
app/Admin/Mutations/Money.php
update($field, $key, $model) changes the field, create($field, $key, $model) returns new fields key => field to add next to it, remove($field, $key, $model) returns true to drop the field. Inside the mutation $this->getModel(), $this->getKey() and $this->fields (all fields of the model) are available. Fields are built once and cached, php artisan admin:cache compiles them in the console and long running processes keep them for the whole worker. A value which depends on the logged administrator or on data of the database belongs into a runtime mutation: it implements Admin\Core\Fields\Mutations\RuntimeMutation and is applied in the administration only, to fields with one of its $attributes, on top of the built fields.
Register mutations in $mutations of a package service provider, or in boot() of the application with Fields::addMutation(Money::class). A mutation is registered once, also when the application boots more times in one process.