registerExtension function
Register a ServiceExtensionHandler that will be invoked in this isolate
for method
. NOTE: Service protocol extensions must be registered
in each isolate.
NOTE: method
must begin with 'ext.' and you should use the following
structure to avoid conflicts with other packages: 'ext.package.command'.
That is, immediately following the 'ext.' prefix, should be the registering
package name followed by another period ('.') and then the command name.
For example: 'ext.dart.io.getOpenFiles'.
Because service extensions are isolate specific, clients using extensions must always include an 'isolateId' parameter with each RPC.
Implementation
void registerExtension(String method, ServiceExtensionHandler handler) {
if (method is! String) {
throw new ArgumentError.value(method, 'method', 'Must be a String');
}
if (!method.startsWith('ext.')) {
throw new ArgumentError.value(method, 'method', 'Must begin with ext.');
}
if (_lookupExtension(method) != null) {
throw new ArgumentError('Extension already registered: $method');
}
if (handler is! ServiceExtensionHandler) {
throw new ArgumentError.value(
handler, 'handler', 'Must be a ServiceExtensionHandler');
}
_registerExtension(method, handler);
}