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The Statecharts community on Spectrum is (along with spectrum) MOVING TO OTHER PLATFORMS: For statecharts discussions in general go to Statecharts Discussion on GitHub or Gitter(https://gitter.im/statecharts/statecharts). For XState-specific questions, go to the XState discussion forum for Q&A or the Stately discord chat to chat.

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Statecharts watercooler

March 7, 2019 at 5:55am
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October 28, 2020 at 3:19pm
that's what I'm using, but that doesn't provide an interface to override things like services on a per-case basis?
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November 6, 2020 at 4:01pm
Would anyone have a good example of how to connect graphQL subscriptions to a state machine? Currently I'm subscribing in a Vue component and sending the result to the state machine to store in its context, but ideally I would want any data fetching/subscribing to be done in the machine instead, so my component can just be an expression of the context/state
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November 9, 2020 at 11:23pm
Using Typescript... if I spawn another machine as an actor and save the ref in context, how should I type it?
I have ServerMachine which spawns instances of SocketMachine and saves them in a sockets array in the context - but what should the type of the array be?
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November 10, 2020 at 1:17pm
currently I've used any but it feels icky
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November 14, 2020 at 2:01pm
Hi all! I'm new to statecharts and I need some help. Let me know if I should ask newbie questions in another channel (failed to find the help one). I have a modal with three states, "a" "b" and "c". I also have 3 possible options to select on the initial "a" screen, let's call these options 1, 2 and 3. These options define state of the modal on certain events, e.g
  • 1 => closeModal
  • 2 => "b" => "c"
  • 3 => "c" What is the best way to describe behavior with xstate? I tried to create to parallel states for modal and option, but failed to trigger state stransitions from the siblings. Any thougths on this?
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November 15, 2020 at 5:53pm
The options are events, not states
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(davidkpiano) Thanks, David! What should I do with options that require multiple modal transitions, like option 2? Is it better to describe it as a separate machine?
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(rreckonerr) have a look at this link https://statecharts.github.io/ to get your head around the basics and try to figure out a state model for your scenario in terms of just sequential states and events*. The guides at https://xstate.js.org/docs/guides/states.html are also useful (start with States and Events) and check out the guide on Guarded Transitions also. Good luck.
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(rreckonerr) and note from the guide : An event is what causes a state machine to transition from its current state to its next state. All state transitions in a state machine are due to these events; state cannot change unless some stimulus (the event) causes it to change.
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(simongandrews) Thank you! I have no problems switching the modal machine from one state to another by sending the events. What I'm trying to grasp is how to combine it with the options that can carry a different logic in between modal's idle and final step. I don't want to keep this option specific logic (on which modal states to trigger and how many of them there're) in component, but rather store it on the option itself, so I could alter the flow only by adjusting an option. I'm wondering if an option can be a driver for the modal machine itself. Will dig into this more this week, sorry if my question is too unclear! Will return with more questions if I get stuck :)
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November 26, 2020 at 10:56am
Does anybody know why assign actions are not called on entry on the initial state? I have a simple example here of my problem ->
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November 27, 2020 at 4:15pm
Does anybody know why assign actions are not called on entry on the initial state? I have a simple example here of my problem ->
This bug was recently fixed, please use the latest version of /fsm
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November 27, 2020 at 11:15pm
I saw it, thanks!
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December 9, 2020 at 7:59pm
Is anyone here using Statecharts to model HDL for FPGAs?
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I'm trying to get a good design pattern going for hierarchical state machines in Hardware Description Language, but I'm new to Statecharts. Consequently, I'm trying to learn from two directions... How to implement Statechart concepts in HDL, and how to produce Statecharts which represent behavior in my existing HDL.
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So a specific question of the second type... how would we use a state chart to represent a conditional action which is independent of a state transition? At present, my best notion would be to, within a state, say do/ if(condition){value = 0} Or similarly, on a state transition (changeState == true) / if (condition2 == true) {value = 0} It just starts to be a lot of pseudocode crammed into an action statement.
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Does anyone know how to access machine context from within interpreter.onDone() method?
I'm struggling with it...
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December 13, 2020 at 6:10pm
So a specific question of the second type... how would we use a state chart to represent a conditional action which is independent of a state transition? At present, my best notion would be to, within a state, say do/ if(condition){value = 0} Or similarly, on a state transition (changeState == true) / if (condition2 == true) {value = 0} It just starts to be a lot of pseudocode crammed into an action statement.
In SCXML, there is <if> for this. In XState, the equivalent is the choose(...) action creator, to give you ideas.
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When using TS and you provide a context Interface, why does the machine allow it to be undefined?
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Shouldn't it force the machine to be modelled according to the context interface if you provide one?
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December 17, 2020 at 3:10pm
Are there other channels/servers for xstate? This seems fairly dead and I have some questions regarding TS
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December 21, 2020 at 6:27am
what's the difference between spawning an actor and spawning a machine? by the looks of the docs they look identical? actors machine
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December 21, 2020 at 4:12pm
what's the difference between spawning an actor and spawning a machine? by the looks of the docs they look identical? actors machine
From my understanding one can describe the behaviour of an actor using a callback, a promise, an observable or a machine. The first docs link you mention simply uses the machine case to describe the general concept.
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Hey all ! I recently made my first statechart using xstate, This statechart isn't directly modelled in the UI layer, as it has two distinct UIs to drive simultaneously. I'm now trying to make it easier to understand in the visualizer by regrouping states that share transitions in compound states (clustering, as this page describes it. While statechard.github.io doesn't make the distinction, xstate lets me choose between creating hierarchical state nodes and invoking other machines/actors. Do you have any guidelines about when to prefer one method over the other ? My guts tell me it's a modularisation/boundaries problem. Also having separate machines allows isolation of the context data. But feel free to correct me.
In addition to this, when creating compound states, I find myself adding more states that don't have a representation in the UI; like final child state nodes. How does a normal xstate + react app handle those to make no re-render happens ?
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December 22, 2020 at 1:23am
For those passing by, I think I'm finding parts of answers to my questions in this thread about decoupling statecharts and views :

Coupling between view and statechart

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