Query<I extends Input, O extends Output> class abstract

A unit of work that reads and answers, and changes nothing.

The CLI counterpart of a read in modular_api. There, the split between reading and writing is imposed by the transport — GraphQL publishes reads, REST publishes the whole use case. A CLI has one transport, so the split has to be declared, and this is the declaration.

A query has no preview because it has nothing to preview, and that absence is the whole difference between it and Command. The two share no method, so neither can be mistaken for the other by accident, and the SDK rejects --plan and --apply on a query without the author writing a line.

Lifecycle (managed by the framework):

  1. Factory function builds the Query from a CliRequest
  2. validate — return an error string, or null when the input is valid
  3. execute — read, and return O
  4. Framework formats O through the active output mode
class ListCommands implements Query<ListInput, ListOutput> {
  @override
  final ListInput input;
  ListCommands(this.input);

  @override
  String? validate() => null;

  @override
  Future<ListOutput> execute() async =>
      ListOutput(Directory(input.path).listSync().map(basename).toList());
}

Constructors

Query()

Properties

hashCode → int
The hash code for this object.
no setterinherited
input → I
The validated input for this invocation.
no setter
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

execute() → Future<O>
Read, and return the answer.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited
validate() → String?
Validate business rules on input. Return a human-readable error string, or null when valid.

Operators

operator ==(Object other) → bool
The equality operator.
inherited