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Composite Collections
Roland Pheasant edited this page Apr 5, 2016
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Dynamic data previously has the capability of applying logic operators to reactive collections. For example, you could combine the results of multiple collections as follows.
var a = new SourceList<int>();
var b = new SourceList<int>();
var c = new SourceList<int>();
var inAll = a.Connect().Or(b.Connect()).Or(c.Connect()); //a logical OR
var inAny = a.Connect().And(b.Connect()).And(c.Connect()); //a logical AND
var inOnlyOne = a.Connect().Xor(b.Connect()).Xor(c.Connect()); //a logical Exclusive OR
var inFirstAndNotAnyOther = a.Connect().Except(b.Connect()).Except(c.Connect()); //a logical Except. i.e. items in a and not (b or c)
From version 4.6 you can now dynamically add or remove collections which are logically combined.
//child lists can be amended any time
var list1 = new SourceList<int>();
var list2 = new SourceList<int>();
var list3 = new SourceList<int>();
var combined = new SourceList<ISourceList<int>>();
//child lists can be added or removed any time
combined.Add(list1);
combined.Add(list2);
combined.Add(list3);
//The operators look after themselves
var inAll = combined.And();
var inAny = combined.Or();
var inOnlyOne = combined.Xor();
var inFirstAndNotAnyOther = combined.Except();
These operators produce an observable with the same signature as a single observable list. And even better than that, it is optimised to give the best possible performance.