prefer_correct_handler_name

v1.0.0WarningConfigurableClass Naming

This rule flags a method passed as an event handler that is not named _onSomething or _handleSomething.

A handler is the other half of the onTap:/onChanged: convention that prefer_correct_callback_field_name enforces on the parameter. When the parameter is onTap: and the method behind it is submit, the call site reads onTap: submit and the reader holds the mapping themselves; onTap: _onTap states it once.

Only a tear-off passed to an on... parameter is considered. A closure is not a named handler, a method called normally is not a handler at all, and a parameter that is not named on... gives the rule no anchor to judge by.

The prefix must start a new word, so _online does not satisfy on.

This rule is in the pedantic preset.

Don’t

Button(onTap: _submit);

Do

Button(onTap: _onTap);
Button(onTap: _handleTap);

Enabling this rule

This rule is in the pedantic preset, so it is enabled by preset: pedantic or by name:

many_lints.yaml

rules:
  prefer_correct_handler_name:
    enabled: true

Options

analysis_options.yaml

analysis_options.yaml

many_lints:
  rules:
    prefer_correct_handler_name:
      prefixes: [on, handle]
      additional_prefixes: [process]
      require_private: true

many_lints.yaml

many_lints.yaml

rules:
  prefer_correct_handler_name:
    prefixes: [on, handle]
    additional_prefixes: [process]
    require_private: true

Option	Type	Default	Description
prefixes	list	[on, handle]	Accepted handler prefixes
additional_prefixes	list	[]	Prefixes to add without replacing the defaults
require_private	bool	true	Whether a handler must also start with an underscore

Turning this rule off

To disable this rule:

many_lints.yaml

rules:
  prefer_correct_handler_name: false

To keep the rule on but skip certain paths, use per-rule exclude.

Related rules

• prefer_correct_callback_field_name — Name callbacks onSomething, the way Flutter does.
• prefer_correct_error_name — Name exception and error classes with the matching suffix.
• prefer_correct_setter_parameter_name — Use one parameter name in every setter.
• prefer_boolean_prefixes — Name booleans as questions.