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POHow to combine n observables dynamically into a list?
 

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  1. POHow to combine n observables dynamically into a list?
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    <p>I have a collection of observables that generate state changes for a so-called <code>Channel</code>. And I have a <code>ChannelSet</code> that should monitor those channels.</p> <p>I would like to write something like this: if one channel is operational, the channel set is up, else, the channel set is down.</p> <pre><code>IEnumerable&lt;ChannelState&gt; channelStates = ...; if (channelStates.Any(cs =&gt; cs == ChannelState.Operational)) channelSet.ChannelSetState = ChannelSetState.Up; else channelSet.ChannelSetState = ChannelSetState.Down; </code></pre> <p>But where do I get my <code>IEnumerable&lt;ChannelState&gt;</code>? If I have 1 channel, I can simply subscribe to its state changes and modify the state of the channel set accordingly. For two channels, I could use <code>CombineLatest</code>:</p> <pre><code>Observable.CombineLatest(channel0States, channel1States, (cs0, cs1) =&gt; { if (cs0 == ChannelSetState.Up || cs1 == ChannelSetState.Up) return ChannelSetState.Up; else return ChannelSetState.Down; }); </code></pre> <p>But I have an <code>IEnumerable&lt;Channel&gt;</code> and a corresponding <code>IEnumerable&lt;IObservable&lt;ChannelState&gt;&gt;</code>. I'm looking for something like <code>CombineLatest</code> that is not limited to a fixed number of observables.</p> <p>To complicate matters, the collection of channels can be added to and removed from. So once in a while, a channel will be added for example. The new channel also generates state changes that need to be incorporated.</p> <p>So what I'm actually looking for is a function:</p> <pre><code>IEnumerable&lt;IObservable&lt;ChannelState&gt;&gt; --&gt; IObservable&lt;ChannelSetState&gt; </code></pre> <p>that keeps up-to-date when the input changes. There should be some way to accomplish this using Rx but I can't really figure out how.</p>
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    1. USRonald Wildenberg
    1. USRonald Wildenberg
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    1. COCan you add details on how new Channels are created?
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      1. USScott Weinstein
    2. COSeems like in this case you need a combination of CombineLatest some sort of Accumulator. I have this problem all of the time with things like Validation (where all objects need to be valid at the same time for the composite validation to be valid). This is a great question.
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      1. USAnderson Imes
    3. CO@Scott What do you want to know about channel creation? They are rather complex objects that wrap a TCP connection.
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      1. USRonald Wildenberg
 

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