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