| 1 | throw new Error("Description for built in functions. Must not be included!");
|
|---|
| 2 | /**
|
|---|
| 3 | * @fileOverview
|
|---|
| 4 | * Documentation of a DIM service Subscription
|
|---|
| 5 | */
|
|---|
| 6 |
|
|---|
| 7 | /**
|
|---|
| 8 | * @class
|
|---|
| 9 | *
|
|---|
| 10 | * Subscription to a DIM service.
|
|---|
| 11 | *
|
|---|
| 12 | * This class represents the subscription to a DIM service. Received
|
|---|
| 13 | * events are first copied to an even queue internally, to avoid
|
|---|
| 14 | * any processing blocking the DIM thread (which could block the
|
|---|
| 15 | * whole network as a result). Then the events are processed.
|
|---|
| 16 | * If a callback is installed, the processing will take place in
|
|---|
| 17 | * another JavaScript thread. Physically it will run synchronously
|
|---|
| 18 | * with the other JavaScript threads. However, the processing blocks
|
|---|
| 19 | * event processing. Consequetly, processing should on average be
|
|---|
| 20 | * faster than the frequency with which events arrive to ensure they
|
|---|
| 21 | * will not fill up the memory and possible reactions to there
|
|---|
| 22 | * contents will happen within a reasonable time and not delayed
|
|---|
| 23 | * too much.
|
|---|
| 24 | *
|
|---|
| 25 | * @param {String} service
|
|---|
| 26 | * Name of the DIM service to which a subscription should be made.
|
|---|
| 27 | * Usully of the form SERVER/SUBSCRIPTION.
|
|---|
| 28 | *
|
|---|
| 29 | * @param {Function} [callback]
|
|---|
| 30 | * An optional function which is set as 'onchange' property.
|
|---|
| 31 | * This can avoid to loose th first event after the subscription
|
|---|
| 32 | * before the callback is set by the 'onchange' property (which
|
|---|
| 33 | * is very unlikely).
|
|---|
| 34 | *
|
|---|
| 35 | * @throws
|
|---|
| 36 | * <li>If number or type of arguments is wrong
|
|---|
| 37 | * <li>If an open subscription to the same service already exists.
|
|---|
| 38 | *
|
|---|
| 39 | * @example
|
|---|
| 40 | * var handle1 = new Subscription("MAGIC_WEATHER/DATA");
|
|---|
| 41 | * var handle2 = new Subscription("TNG_WEATHER/DATA", function(evt) { console.out(JSON.stringify(evt)); });
|
|---|
| 42 | * ...
|
|---|
| 43 | * handle2.close();
|
|---|
| 44 | * handle1.close();
|
|---|
| 45 | */
|
|---|
| 46 | function Subscription(service, callback)
|
|---|
| 47 | {
|
|---|
| 48 | /**
|
|---|
| 49 | *
|
|---|
| 50 | * The name of the service subscribed to.
|
|---|
| 51 | *
|
|---|
| 52 | * @constant
|
|---|
| 53 | * @type String
|
|---|
| 54 | *
|
|---|
| 55 | */
|
|---|
| 56 | this.name = service;
|
|---|
| 57 |
|
|---|
| 58 | /**
|
|---|
| 59 | *
|
|---|
| 60 | * Boolean value which is set to false if the Subscription was closed.
|
|---|
| 61 | *
|
|---|
| 62 | * @type Boolean
|
|---|
| 63 | *
|
|---|
| 64 | */
|
|---|
| 65 | this.isOpen = false;
|
|---|
| 66 |
|
|---|
| 67 | /**
|
|---|
| 68 | *
|
|---|
| 69 | * Callback in case of event reception.
|
|---|
| 70 | *
|
|---|
| 71 | * To install a callback in case a new event of this Subscription
|
|---|
| 72 | * was received, set this property to a function. The argument
|
|---|
| 73 | * provided to the function is identical with the object returned
|
|---|
| 74 | * by Subscription.get(). For the code executed, the same rules apply
|
|---|
| 75 | * than for a thread created with Thread.
|
|---|
| 76 | *
|
|---|
| 77 | * @type Function
|
|---|
| 78 | *
|
|---|
| 79 | * @example
|
|---|
| 80 | * handle.onchange = function(event) { console.out(JSON.stringify(event); };
|
|---|
| 81 | *
|
|---|
| 82 | */
|
|---|
| 83 | this.onchange = callback;
|
|---|
| 84 |
|
|---|
| 85 | /**
|
|---|
| 86 | *
|
|---|
| 87 | * Returns the last received event of this subscription.
|
|---|
| 88 | *
|
|---|
| 89 | * @param {Integer} [timeout=0]
|
|---|
| 90 | * A timeout in millisecond to wait for an event to arrive.
|
|---|
| 91 | * This timeout only applied if no event has been received yet
|
|---|
| 92 | * after a new Subscription has been created. If an event
|
|---|
| 93 | * is already available, the event is returned. If the timeout
|
|---|
| 94 | * is 'null', waiting will never timeout until an event was received.
|
|---|
| 95 | * If the timeout is less than zero, no exception will be thrown,
|
|---|
| 96 | * but 'undefined' returned in case of timeout. The corresponding
|
|---|
| 97 | * timeout is then Math.abs(timeout).
|
|---|
| 98 | *
|
|---|
| 99 | * @param {Boolean} [requireNamed=true]
|
|---|
| 100 | * Usually an event is only considered complete, if also the
|
|---|
| 101 | * corresponding decription is available distributed through
|
|---|
| 102 | * the service SERVER/SERVICE_DESC. If an event has no
|
|---|
| 103 | * description or access to the data by name is not important,
|
|---|
| 104 | * requireNamed can be set to false.
|
|---|
| 105 | *
|
|---|
| 106 | * @throws
|
|---|
| 107 | * <li> If number or type of arguments is wrong
|
|---|
| 108 | * <li> After a timeout, if the timeout value was greater or equal zero
|
|---|
| 109 | * <li> If conversion of the received data to an event object has failed
|
|---|
| 110 | *
|
|---|
| 111 | * @returns {Event}
|
|---|
| 112 | * A valid event is returned, undefined in the case waiting for an
|
|---|
| 113 | * event has timed out and exceptions are supressed by a negative
|
|---|
| 114 | * timeout.
|
|---|
| 115 | *
|
|---|
| 116 | */
|
|---|
| 117 | this.get = function() { /* [native code] */ }
|
|---|
| 118 |
|
|---|
| 119 | /**
|
|---|
| 120 | *
|
|---|
| 121 | * Unsubscribe from an existing subscription. Note that all open
|
|---|
| 122 | * subscription produce network traffic and should be omitted if
|
|---|
| 123 | * not needed.
|
|---|
| 124 | *
|
|---|
| 125 | * @returns {Boolean}
|
|---|
| 126 | * true if the subscription was still open, false if it was
|
|---|
| 127 | * already closed.
|
|---|
| 128 | *
|
|---|
| 129 | */
|
|---|
| 130 | this.close() = function() { /* [native code] */ }
|
|---|
| 131 | }
|
|---|
