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nv/html/nv-nopdf/styles/packages/reactive-var.js

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+//////////////////////////////////////////////////////////////////////////
+//                                                                      //
+// This is a generated file. You can view the original                  //
+// source in your browser if your browser supports source maps.         //
+// Source maps are supported by all recent versions of Chrome, Safari,  //
+// and Firefox, and by Internet Explorer 11.                            //
+//                                                                      //
+//////////////////////////////////////////////////////////////////////////
+
+
+(function () {
+
+/* Imports */
+var Meteor = Package.meteor.Meteor;
+var global = Package.meteor.global;
+var meteorEnv = Package.meteor.meteorEnv;
+var Tracker = Package.tracker.Tracker;
+var Deps = Package.tracker.Deps;
+
+/* Package-scope variables */
+var ReactiveVar;
+
+(function(){
+
+//////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+//                                                                                                              //
+// packages/reactive-var/reactive-var.js                                                                        //
+//                                                                                                              //
+//////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+                                                                                                                //
+/*
+ * ## [new] ReactiveVar(initialValue, [equalsFunc])
+ *
+ * A ReactiveVar holds a single value that can be get and set,
+ * such that calling `set` will invalidate any Computations that
+ * called `get`, according to the usual contract for reactive
+ * data sources.
+ *
+ * A ReactiveVar is much like a Session variable -- compare `foo.get()`
+ * to `Session.get("foo")` -- but it doesn't have a global name and isn't
+ * automatically migrated across hot code pushes.  Also, while Session
+ * variables can only hold JSON or EJSON, ReactiveVars can hold any value.
+ *
+ * An important property of ReactiveVars, which is sometimes the reason
+ * to use one, is that setting the value to the same value as before has
+ * no effect, meaning ReactiveVars can be used to absorb extra
+ * invalidations that wouldn't serve a purpose.  However, by default,
+ * ReactiveVars are extremely conservative about what changes they
+ * absorb.  Calling `set` with an object argument will *always* trigger
+ * invalidations, because even if the new value is `===` the old value,
+ * the object may have been mutated.  You can change the default behavior
+ * by passing a function of two arguments, `oldValue` and `newValue`,
+ * to the constructor as `equalsFunc`.
+ *
+ * This class is extremely basic right now, but the idea is to evolve
+ * it into the ReactiveVar of Geoff's Lickable Forms proposal.
+ */
+
+/**
+ * @class 
+ * @instanceName reactiveVar
+ * @summary Constructor for a ReactiveVar, which represents a single reactive variable.
+ * @locus Client
+ * @param {Any} initialValue The initial value to set.  `equalsFunc` is ignored when setting the initial value.
+ * @param {Function} [equalsFunc] Optional.  A function of two arguments, called on the old value and the new value whenever the ReactiveVar is set.  If it returns true, no set is performed.  If omitted, the default `equalsFunc` returns true if its arguments are `===` and are of type number, boolean, string, undefined, or null.
+ */
+ReactiveVar = function (initialValue, equalsFunc) {
+  if (! (this instanceof ReactiveVar))
+    // called without `new`
+    return new ReactiveVar(initialValue, equalsFunc);
+
+  this.curValue = initialValue;
+  this.equalsFunc = equalsFunc;
+  this.dep = new Tracker.Dependency;
+};
+
+ReactiveVar._isEqual = function (oldValue, newValue) {
+  var a = oldValue, b = newValue;
+  // Two values are "equal" here if they are `===` and are
+  // number, boolean, string, undefined, or null.
+  if (a !== b)
+    return false;
+  else
+    return ((!a) || (typeof a === 'number') || (typeof a === 'boolean') ||
+            (typeof a === 'string'));
+};
+
+/**
+ * @summary Returns the current value of the ReactiveVar, establishing a reactive dependency.
+ * @locus Client
+ */
+ReactiveVar.prototype.get = function () {
+  if (Tracker.active)
+    this.dep.depend();
+
+  return this.curValue;
+};
+
+/**
+ * @summary Sets the current value of the ReactiveVar, invalidating the Computations that called `get` if `newValue` is different from the old value.
+ * @locus Client
+ * @param {Any} newValue
+ */
+ReactiveVar.prototype.set = function (newValue) {
+  var oldValue = this.curValue;
+
+  if ((this.equalsFunc || ReactiveVar._isEqual)(oldValue, newValue))
+    // value is same as last time
+    return;
+
+  this.curValue = newValue;
+  this.dep.changed();
+};
+
+ReactiveVar.prototype.toString = function () {
+  return 'ReactiveVar{' + this.get() + '}';
+};
+
+ReactiveVar.prototype._numListeners = function() {
+  // Tests want to know.
+  // Accesses a private field of Tracker.Dependency.
+  var count = 0;
+  for (var id in this.dep._dependentsById)
+    count++;
+  return count;
+};
+
+//////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+}).call(this);
+
+
+/* Exports */
+Package._define("reactive-var", {
+  ReactiveVar: ReactiveVar
+});
+
+})();