26 | * This programming interface lets a JavaScript client application use the MQTT V3.1 or 27 | * V3.1.1 protocol to connect to an MQTT-supporting messaging server. 28 | * 29 | * The function supported includes: 30 | *
38 | * The API consists of two main objects: 39 | *
51 | * The programming interface validates parameters passed to it, and will throw 52 | * an Error containing an error message intended for developer use, if it detects 53 | * an error with any parameter. 54 | *
55 | * Example:
56 | *
57 | *
58 | client = new Paho.MQTT.Client(location.hostname, Number(location.port), "clientId");
59 | client.onConnectionLost = onConnectionLost;
60 | client.onMessageArrived = onMessageArrived;
61 | client.connect({onSuccess:onConnect});
62 |
63 | function onConnect() {
64 | // Once a connection has been made, make a subscription and send a message.
65 | console.log("onConnect");
66 | client.subscribe("/World");
67 | message = new Paho.MQTT.Message("Hello");
68 | message.destinationName = "/World";
69 | client.send(message);
70 | };
71 | function onConnectionLost(responseObject) {
72 | if (responseObject.errorCode !== 0)
73 | console.log("onConnectionLost:"+responseObject.errorMessage);
74 | };
75 | function onMessageArrived(message) {
76 | console.log("onMessageArrived:"+message.payloadString);
77 | client.disconnect();
78 | };
79 | *
1541 | * Most applications will create just one Client object and then call its connect() method, 1542 | * however applications can create more than one Client object if they wish. 1543 | * In this case the combination of host, port and clientId attributes must be different for each Client object. 1544 | *
1545 | * The send, subscribe and unsubscribe methods are implemented as asynchronous JavaScript methods 1546 | * (even though the underlying protocol exchange might be synchronous in nature). 1547 | * This means they signal their completion by calling back to the application, 1548 | * via Success or Failure callback functions provided by the application on the method in question. 1549 | * Such callbacks are called at most once per method invocation and do not persist beyond the lifetime 1550 | * of the script that made the invocation. 1551 | *
1552 | * In contrast there are some callback functions, most notably onMessageArrived, 1553 | * that are defined on the {@link Paho.MQTT.Client} object. 1554 | * These may get called multiple times, and aren't directly related to specific method invocations made by the client. 1555 | * 1556 | * @name Paho.MQTT.Client 1557 | * 1558 | * @constructor 1559 | * 1560 | * @param {string} host - the address of the messaging server, as a fully qualified WebSocket URI, as a DNS name or dotted decimal IP address. 1561 | * @param {number} port - the port number to connect to - only required if host is not a URI 1562 | * @param {string} path - the path on the host to connect to - only used if host is not a URI. Default: '/mqtt'. 1563 | * @param {string} clientId - the Messaging client identifier, between 1 and 23 characters in length. 1564 | * 1565 | * @property {string} host - read only the server's DNS hostname or dotted decimal IP address. 1566 | * @property {number} port - read only the server's port. 1567 | * @property {string} path - read only the server's path. 1568 | * @property {string} clientId - read only used when connecting to the server. 1569 | * @property {function} onConnectionLost - called when a connection has been lost. 1570 | * after a connect() method has succeeded. 1571 | * Establish the call back used when a connection has been lost. The connection may be 1572 | * lost because the client initiates a disconnect or because the server or network 1573 | * cause the client to be disconnected. The disconnect call back may be called without 1574 | * the connectionComplete call back being invoked if, for example the client fails to 1575 | * connect. 1576 | * A single response object parameter is passed to the onConnectionLost callback containing the following fields: 1577 | *
2112 | * All attributes may be null, which implies the default values. 2113 | * 2114 | * @name Paho.MQTT.Message 2115 | * @constructor 2116 | * @param {String|ArrayBuffer} payload The message data to be sent. 2117 | *
2118 | * @property {string} payloadString read only The payload as a string if the payload consists of valid UTF-8 characters. 2119 | * @property {ArrayBuffer} payloadBytes read only The payload as an ArrayBuffer. 2120 | *
2121 | * @property {string} destinationName mandatory The name of the destination to which the message is to be sent 2122 | * (for messages about to be sent) or the name of the destination from which the message has been received. 2123 | * (for messages received by the onMessage function). 2124 | *
2125 | * @property {number} qos The Quality of Service used to deliver the message. 2126 | *
2132 | * @property {Boolean} retained If true, the message is to be retained by the server and delivered 2133 | * to both current and future subscriptions. 2134 | * If false the server only delivers the message to current subscribers, this is the default for new Messages. 2135 | * A received message has the retained boolean set to true if the message was published 2136 | * with the retained boolean set to true 2137 | * and the subscrption was made after the message has been published. 2138 | *
2139 | * @property {Boolean} duplicate read only If true, this message might be a duplicate of one which has already been received. 2140 | * This is only set on messages received from the server. 2141 | * 2142 | */ 2143 | var Message = function(newPayload) { 2144 | var payload; 2145 | if (typeof newPayload === "string" 2146 | || newPayload instanceof ArrayBuffer 2147 | || newPayload instanceof Int8Array 2148 | || newPayload instanceof Uint8Array 2149 | || newPayload instanceof Int16Array 2150 | || newPayload instanceof Uint16Array 2151 | || newPayload instanceof Int32Array 2152 | || newPayload instanceof Uint32Array 2153 | || newPayload instanceof Float32Array 2154 | || newPayload instanceof Float64Array 2155 | ) { 2156 | payload = newPayload; 2157 | } else { 2158 | throw (format(ERROR.INVALID_ARGUMENT, [newPayload, "newPayload"])); 2159 | } 2160 | 2161 | this._getPayloadString = function() { 2162 | if (typeof payload === "string") 2163 | return payload; 2164 | else 2165 | return parseUTF8(payload, 0, payload.length); 2166 | }; 2167 | 2168 | this._getPayloadBytes = function() { 2169 | if (typeof payload === "string") { 2170 | var buffer = new ArrayBuffer(UTF8Length(payload)); 2171 | var byteStream = new Uint8Array(buffer); 2172 | stringToUTF8(payload, byteStream, 0); 2173 | 2174 | return byteStream; 2175 | } else { 2176 | return payload; 2177 | } 2178 | ; 2179 | }; 2180 | 2181 | var destinationName = undefined; 2182 | this._getDestinationName = function() { 2183 | return destinationName; 2184 | }; 2185 | this._setDestinationName = function(newDestinationName) { 2186 | if (typeof newDestinationName === "string") 2187 | destinationName = newDestinationName; 2188 | else 2189 | throw new Error(format(ERROR.INVALID_ARGUMENT, [newDestinationName, "newDestinationName"])); 2190 | }; 2191 | 2192 | var qos = 0; 2193 | this._getQos = function() { 2194 | return qos; 2195 | }; 2196 | this._setQos = function(newQos) { 2197 | if (newQos === 0 || newQos === 1 || newQos === 2) 2198 | qos = newQos; 2199 | else 2200 | throw new Error("Invalid argument:" + newQos); 2201 | }; 2202 | 2203 | var retained = false; 2204 | this._getRetained = function() { 2205 | return retained; 2206 | }; 2207 | this._setRetained = function(newRetained) { 2208 | if (typeof newRetained === "boolean") 2209 | retained = newRetained; 2210 | else 2211 | throw new Error(format(ERROR.INVALID_ARGUMENT, [newRetained, "newRetained"])); 2212 | }; 2213 | 2214 | var duplicate = false; 2215 | this._getDuplicate = function() { 2216 | return duplicate; 2217 | }; 2218 | this._setDuplicate = function(newDuplicate) { 2219 | duplicate = newDuplicate; 2220 | }; 2221 | }; 2222 | 2223 | Message.prototype = { 2224 | get payloadString() { 2225 | return this._getPayloadString(); 2226 | }, 2227 | get payloadBytes() { 2228 | return this._getPayloadBytes(); 2229 | }, 2230 | 2231 | get destinationName() { 2232 | return this._getDestinationName(); 2233 | }, 2234 | set destinationName(newDestinationName) { 2235 | this._setDestinationName(newDestinationName); 2236 | }, 2237 | 2238 | get qos() { 2239 | return this._getQos(); 2240 | }, 2241 | set qos(newQos) { 2242 | this._setQos(newQos); 2243 | }, 2244 | 2245 | get retained() { 2246 | return this._getRetained(); 2247 | }, 2248 | set retained(newRetained) { 2249 | this._setRetained(newRetained); 2250 | }, 2251 | 2252 | get duplicate() { 2253 | return this._getDuplicate(); 2254 | }, 2255 | set duplicate(newDuplicate) { 2256 | this._setDuplicate(newDuplicate); 2257 | } 2258 | }; 2259 | 2260 | // Module contents. 2261 | return { 2262 | Client: Client, 2263 | Message: Message 2264 | }; 2265 | }) 2266 | (window); 2267 | 2268 | if(module && module.exports) module.exports=Paho; --------------------------------------------------------------------------------