public static void DemonstrateVarAndExpression()
{
// A ReactiveVar is a simple mutable object with a Set method to update it in its entirety. It can turn
// any existing type--often a primitive type--into a reactive type. You can create it with "new" or,
// more concisely, with the factory method
ReactiveVar <int> var1 = new ReactiveVar <int>(1);
ReactiveVar <int> var2 = ReactiveVar(2);
// A ReactiveExpression is computed based on other reactive data. When any of the components change, the expression itself changes
Reactive <int> sumExpression = ReactiveExpression(() => var1.Value + var2.Value);
// Expressions can depend on other expressions. They can call nested functions too, being arbitrarily complex
Reactive <int> doubleSumExpression = ReactiveExpression(() => sumExpression.Value * 2);
// React to changes in doubleSumExpression using the Changed event, showing a message when it changes.
// Changed is used to run code with side effects when reactive data changes. It can, for instance, update UI.
doubleSumExpression.Changed += () => {
Console.WriteLine($"Double sum is now: {doubleSumExpression.Value}");
};
// All updates are made inside a transaction; if you try to update data outside a transaction, you'll get an error
Transaction.Start();
var1.Set(3);
var2.Set(2);
// Note that Changed notifications are only sent when the Transaction completes. That ensures all data is in it's final state and no "glitches" are possible.
Console.WriteLine($"About to commit transaction; should show a new value of 10");
Transaction.End();
}
public void TestIndexedListOnReactiveSequence()
{
var length = new ReactiveVar <int>(2);
ParentSequence <int> rootSequence = Sequences(
Items(0, 1, 2),
Sequences(
Expression(() => CreateTestSequenceOfLength(length.Value)),
Items(3, 4, 5)
)
);
var list = new List <int>();
new IndexedListOnSequence <int>(new ListInterfaceIndexedList <int>(list), rootSequence);
AssertListRangeIs(list, start: 0, end: 3, firstValue: 0);
AssertListRangeIs(list, start: 3, end: 5, firstValue: 100);
AssertListRangeIs(list, start: 5, end: 8, firstValue: 3);
Assert.AreEqual(8, list.Count);
Transaction.Run(() => length.Set(3));
AssertListRangeIs(list, start: 0, end: 3, firstValue: 0);
AssertListRangeIs(list, start: 3, end: 6, firstValue: 100);
AssertListRangeIs(list, start: 6, end: 9, firstValue: 3);
Assert.AreEqual(9, list.Count);
Transaction.Run(() => length.Set(0));
AssertListRangeIs(list, start: 0, end: 3, firstValue: 0);
AssertListRangeIs(list, start: 3, end: 6, firstValue: 3);
Assert.AreEqual(6, list.Count);
}
public void TestNestedExpressions()
{
var term1 = new ReactiveVar <int>(1);
var term2 = new ReactiveVar <int>(2);
var subexpression = new ReactiveExpression <int>(() => term1.Value + term2.Value);
ChangedCalled subexpressionChangedCalled = EnsureChangedCalled(subexpression);
var term3 = new ReactiveVar <int>(3);
var expression = new ReactiveExpression <int>(() => subexpression.Value + term3.Value);
ChangedCalled expressionChangeCalled = EnsureChangedCalled(expression);
Transaction.Start();
term3.Set(5);
CompleteTransactionAndAssertChangedCalled(expressionChangeCalled);
Assert.AreEqual(8, expression.Value);
expressionChangeCalled.Reset();
Transaction.Start();
term1.Set(10);
CompleteTransactionAndAssertChangedCalled(expressionChangeCalled);
subexpressionChangedCalled.AssertCalled();
Assert.AreEqual(17, expression.Value);
}
public void TestSet()
{
var reactiveVar = new ReactiveVar <int>(1);
ChangedCalled changedCalled = EnsureChangedCalled(reactiveVar);
Transaction.Start();
reactiveVar.Set(2);
changedCalled.AssertNotCalled();
Transaction.End();
changedCalled.AssertCalled();
Assert.AreEqual(2, reactiveVar.Value);
}
public void TestSimpleExpression()
{
var term1 = new ReactiveVar <int>(1);
var term2 = new ReactiveVar <int>(2);
var expression = new ReactiveExpression <int>(() => term1.Value + term2.Value);
Assert.AreEqual(3, expression.Value);
ChangedCalled changedCalled = EnsureChangedCalled(expression);
Transaction.Start();
term1.Set(3);
term2.Set(4);
CompleteTransactionAndAssertChangedCalled(changedCalled);
Assert.AreEqual(7, expression.Value);
changedCalled = EnsureChangedCalled(expression);
Transaction.Start();
term1.Set(5);
CompleteTransactionAndAssertChangedCalled(changedCalled);
Assert.AreEqual(9, expression.Value);
}