<> See also: * [[ROS/Master_Slave_APIs|Master Slave APIs]] * [[ROS/Slave_API|Slave API]] * [[ROS/Parameter Server API|Parameter Server API]] == Using XMLRPC == The Master API is implemented via XMLRPC, which has good library support in a variety of languages. For example, in Python: {{{ import os import xmlrpclib caller_id = '/script' m = xmlrpclib.ServerProxy(os.environ['ROS_MASTER_URI']) code, msg, val = m.getSystemState(caller_id) if code == 1: pubs, subs, srvs = val else: print "call failed", code, msg }}} == API Listing == '''Language-specific client APIs as well as tools may define convenience methods that make it unnecessary to call these APIs directly.''' === register/unregister methods === `registerService(caller_id, service, service_api, caller_api)` Register the caller as a provider of the specified service. <
> ''Parameters'' `caller_id` (str) ROS caller ID `service` (str) Fully-qualified name of service `service_api` (str) ROSRPC Service URI `caller_api` (str) XML-RPC URI of caller node ''Returns'' (int, str, int) (code, statusMessage, ignore) `unregisterService(caller_id, service, service_api)` Unregister the caller as a provider of the specified service. <
> ''Parameters'' `caller_id` (str) ROS caller ID `service` (str) Fully-qualified name of service `service_api` (str) API URI of service to unregister. Unregistration will only occur if current registration matches. ''Returns'' (int, str, int) (code, statusMessage, numUnregistered). <
> Number of unregistrations (either 0 or 1). If this is zero it means that the caller was not registered as a service provider. The call still succeeds as the intended final state is reached. `registerSubscriber(caller_id, topic, topic_type, caller_api)` Subscribe the caller to the specified topic. In addition to receiving a list of current publishers, the subscriber will also receive notifications of new publishers via the publisherUpdate API. <
> ''Parameters'' `caller_id` (str) ROS caller ID `topic` (str) Fully-qualified name of topic. `topic_type` (str) Datatype for topic. Must be a package-resource name, i.e. the .msg name. `caller_api` (str) API URI of subscriber to register. Will be used for new publisher notifications. ''Returns'' (int, str, [str]) (code, statusMessage, publishers) <
> Publishers is a list of XMLRPC API URIs for nodes currently publishing the specified topic. `unregisterSubscriber(caller_id, topic, caller_api)` Unregister the caller as a publisher of the topic. <
> ''Parameters'' `caller_id` (str) ROS caller ID `topic` (str) Fully-qualified name of topic. `caller_api` (str) API URI of subscriber to unregister. Unregistration will only occur if current registration matches. ''Returns'' (int, str, int) (code, statusMessage, numUnsubscribed) <
> If numUnsubscribed is zero it means that the caller was not registered as a subscriber. The call still succeeds as the intended final state is reached. `registerPublisher(caller_id, topic, topic_type, caller_api)` Register the caller as a publisher the topic. <
> ''Parameters'' `caller_id` (str) ROS caller ID `topic` (str) Fully-qualified name of topic to register. `topic_type` (str) Datatype for topic. Must be a package-resource name, i.e. the .msg name. `caller_api` (str) API URI of publisher to register. ''Returns'' (int, str, [str]) (code, statusMessage, subscriberApis) <
> List of current subscribers of topic in the form of XMLRPC URIs. `unregisterPublisher(caller_id, topic, caller_api)` Unregister the caller as a publisher of the topic. <
> ''Parameters'' `caller_id` (str) ROS caller ID `topic` (str) Fully-qualified name of topic to unregister. `caller_api` (str) API URI of publisher to unregister. Unregistration will only occur if current registration matches. ''Returns'' (int, str, int) (code, statusMessage, numUnregistered) <
> If numUnregistered is zero it means that the caller was not registered as a publisher. The call still succeeds as the intended final state is reached. === Name service and system state === `lookupNode(caller_id, node_name)` Get the XML-RPC URI of the node with the associated name/caller_id. This API is for looking information about publishers and subscribers. Use lookupService instead to lookup ROS-RPC URIs. <
> ''Parameters'' `caller_id` (str) ROS caller ID `node` (str) Name of node to lookup ''Returns'' (int, str, str) (code, statusMessage, URI) `getPublishedTopics(caller_id, subgraph)` Get list of topics that can be subscribed to. This does not return topics that have no publishers. See getSystemState() to get more comprehensive list. <
> ''Parameters'' `caller_id` (str) ROS caller ID `subgraph` (str) Restrict topic names to match within the specified subgraph. Subgraph namespace is resolved relative to the caller's namespace. Use empty string to specify all names. ''Returns'' (int, str, [[str, str],]) (code, statusMessage, [ [topic1, type1]...[topicN, typeN] ]) `getTopicTypes(caller_id)` Retrieve list topic names and their types. <
> ''Parameters'' `caller_id` (str) ROS caller ID ''Returns'' (int, str, [ [str,str] ]) (code, statusMessage, topicTypes) <
> topicTypes is a list of [topicName, topicType] pairs. `getSystemState(caller_id)` Retrieve list representation of system state (i.e. publishers, subscribers, and services). <
> ''Parameters'' `caller_id` (str) ROS caller ID ''Returns'' (int, str, [ [str,[str] ], [str,[str] ], [str,[str] ] ]) (code, statusMessage, systemState) <
> System state is in list representation {{{ [publishers, subscribers, services] }}} publishers is of the form{{{ [ [topic1, [topic1Publisher1...topic1PublisherN]] ... ] }}} subscribers is of the form{{{ [ [topic1, [topic1Subscriber1...topic1SubscriberN]] ... ] }}} services is of the form{{{ [ [service1, [service1Provider1...service1ProviderN]] ... ] }}} `getUri(caller_id)` Get the URI of the master. <
> ''Parameters'' `caller_id` (str) ROS caller ID ''Returns'' (int, str, str) (code, statusMessage, masterURI) `lookupService(caller_id, service)` Lookup all provider of a particular service. <
> ''Parameters'' `caller_id` (str) ROS caller ID `service` (str) Fully-qualified name of service ''Returns'' (int, str, str) (code, statusMessage, serviceUrl) <
> service URL is provides address and port of the service. Fails if there is no provider.