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@minshallj /foo.js
Last active Apr 19, 2016

What would you like to do?
roslibjs example
//* The Ros object, wrapping a web socket connection to rosbridge.
var ros = new ROSLIB.Ros({
url: 'ws://localhost:9090' // url to your rosbridge server
});
//* A topic for messaging.
var exampleTopic = new ROSLIB.Topic({
ros: ros,
name: '/com/endpoint/example', // use a sensible namespace
messageType: 'std_msgs/String'
});
/**
* Serializes an object and publishes it to a std_msgs/String topic.
* @param {ROSLIB.Topic} topic
* A topic to publish to. Must use messageType: std_msgs/String
* @param {Object} obj
* Any object that can be serialized with JSON.stringify
*/
function publishEncoded(topic, obj) {
var msg = new ROSLIB.Message({
data: JSON.stringify(obj)
});
topic.publish(msg);
}
/**
* Decodes an object from a std_msgs/String message.
* @param {Object} msg
* Message from a std_msgs/String topic.
* @return {Object}
* Decoded object from the message.
*/
function decodeMessage(msg) {
return JSON.parse(msg.data);
}
/**
* Typed messaging wrapper for a std_msgs/String ROS Topic.
* @param {ROSLIB.Topic} topic
* A std_msgs/String ROS Topic for multiplexed messaging.
* @constructor
*/
function RosTypedMessaging(topic) {
this.topic = topic;
this.topic.subscribe(this.handleMessage_.bind(this));
}
RosTypedMessaging.prototype.__proto__ = EventEmitter2.prototype;
/**
* Handles an incoming message from the topic by firing an event.
* @param {Object} msg
* @private
*/
RosTypedMessaging.prototype.handleMessage_ = function(msg) {
var decoded = decodeMessage(msg);
var type = decoded.type;
var data = decoded.data;
this.emit(type, data);
};
/**
* Sends a typed message to the topic.
* @param {String} type
* @param {Object} data
*/
RosTypedMessaging.prototype.sendMessage = function(type, data) {
var msg = {type: type, data: data};
publishEncoded(this.topic, msg);
};
//* Example implementation of RosTypedMessaging.
var myMessageChannel = new RosTypedMessaging(exampleTopic);
myMessageChannel.on('fooo', function(data) {
console.log('fooo!', data);
});
setInterval(function() {
var mySyncObject = {
time: Date.now(),
myFavoriteColor: 'red'
};
myMessageChannel.sendMessage('fooo', mySyncObject);
}, 1000);
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