dbus

Description:

dbus

A native Dart client implementation of D-Bus.
Accessing remote objects #
The easiest way to get started is to generate Dart classes from a D-Bus interface definition, for example:
<node name="/com/example/Test/Object">
<interface name="com.example.Test">
<property name="Version" type="s" access="read"/>
<method name="ReverseText">
<arg name="input" type="s" direction="in"/>
<arg name="output" type="s" direction="out"/>
</method>
</interface>
</node>
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The dart-dbus tool processes this interface to generate a Dart source file:
$ dart-dbus generate-remote-object test-object.xml -o test-remote-object.dart
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You can then use the generated test-remote-object.dart to access that remote object from your program:
import 'package:dbus/dbus.dart';
import 'test-remote-object.dart';

Future<void> main() async {
var client = DBusClient.session();
var object = ComExampleTestObject(client, 'com.example.Test');
var version = await object.getVersion();
print('version: $version');
var reversedText = await object.callReverseText('Hello World');
print(reversedText);
await client.close();
}
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The code generated by dart-dbus may not be the cleanest API you want to expose for your service. It is recommended that you use the generated code as a starting point and then modify it as necessary.
Exporting local objects #
The above interface definition can also be processed to generate a class for exporting this object.
$ dart-dbus generate-object test-object.xml -o test-object.dart
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You can then use the generated test-object.dart in your program:
import 'package:dbus/dbus.dart';
import 'test-object.dart';

class TestObject extends ComExampleTestObject {
@override
Future<DBusMethodResponse> getVersion() async {
return DBusGetPropertyResponse(DBusString('1.2'));
}

@override
Future<DBusMethodResponse> doReverseText(String input) async {
var reversedText = String.fromCharCodes(input.codeUnits.reversed);
return DBusMethodSuccessResponse([DBusString(reversedText)]);
}
}

Future<void> main() async {
var client = DBusClient.session();
await client.requestName('com.example.Test');
await client.registerObject(TestObject());
}
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Using objects without dbus-dart #
You can also choose to access D-Bus objects directly without interface definitions and dbus-dart.
This requires writing more code and handing more error cases.
The following code shows how to access the remote object in the above examples:
import 'package:dbus/dbus.dart';

Future<void> main() async {
var client = DBusClient.session();
var object = DBusRemoteObject(client, name: 'com.example.Test', path: DBusObjectPath('/com/example/Test/Object'));
var value = await object.getProperty('com.example.Test', 'Version', signature: DBusSignature('s'));
var version = value.asString();
print('version: $version');
var response = await object.callMethod('com.example.Test', 'ReverseText', [DBusString('Hello World')], replySignature: DBusSignature('s'));
var reversedText = response.values[0].asString();
print('$reversedText');
await client.close();
}
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And the following shows how to export that object:
import 'package:dbus/dbus.dart';

class TestObject extends DBusObject {
TestObject() : super(DBusObjectPath('/com/example/Test/Object'));

@override
Future<DBusMethodResponse> getProperty(String interface, String name) async {
if (interface == 'com.example.Test' && name == 'Version') {
return DBusGetPropertyResponse(DBusString('1.2'));
} else {
return DBusMethodErrorResponse.unknownProperty();
}
}

@override
Future<DBusMethodResponse> handleMethodCall(DBusMethodCall methodCall) async {
if (methodCall.interface == 'com.example.Test') {
if (methodCall.name == 'ReverseText') {
if (methodCall.signature != DBusSignature('s')) {
return DBusMethodErrorResponse.invalidArgs();
}
var input = methodCall.values[0].asString();
var reversedText = String.fromCharCodes(input.codeUnits.reversed);
return DBusMethodSuccessResponse([DBusString(reversedText)]);
} else {
return DBusMethodErrorResponse.unknownMethod();
}
} else {
return DBusMethodErrorResponse.unknownInterface();
}
}
}

Future<void> main() async {
var client = DBusClient.session();
await client.requestName('com.example.Test');
await client.registerObject(TestObject());
}
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Contributing to dbus.dart #
We welcome contributions! See the contribution guide for more details.